16 Jun 2004 13:31:28
Nigel
How much power is in a 100ah battery

Stupid question time...
If I have a 100ah battery how much power can I expect to get out of it... is
100ah the total battery capacity or it's useable/available capacity. My
understanding is that a normal lead acid battery shouldn't be run too flat,
so when is flat too flat? If I should only let my battery drain down to say
a 90% charge, have I only got 10ah before I need to recharge?




16 Jun 2004 13:52:38
Steve Brassett
Re: How much power is in a 100ah battery


"Nigel" <jassira53@hotmail.com > wrote in message
news:40d03da0$0$4586$db0fefd9@news.zen.co.uk...
> Stupid question time...
> If I have a 100ah battery how much power can I expect to get out of
it... is
> 100ah the total battery capacity or it's useable/available capacity.
My
> understanding is that a normal lead acid battery shouldn't be run
too flat,
> so when is flat too flat? If I should only let my battery drain down
to say
> a 90% charge, have I only got 10ah before I need to recharge?

If it is a "leisure" or deep discharge battery, then conventional
wisdom is that it shouldn't drop below 50% of charge. This sort
of battery would normally be used for the "domestic" stuff on
your boat.

A "normal" or engine-starting battery is designed to give high
current for short periods of time, then be charged straight away,
so it is more difficult to give a value.

I don't suppose that has helped much.

--
Steve Brassett



16 Jun 2004 08:53:03
Doug Dotson
Re: How much power is in a 100ah battery

100AH is its total capacity. Normal rule of thumb is to only
discharge it down to 50%. So, you have 50AH of useful
capacity.

Doug
s/v Callista

"Nigel" <jassira53@hotmail.com > wrote in message
news:40d03da0$0$4586$db0fefd9@news.zen.co.uk...
> Stupid question time...
> If I have a 100ah battery how much power can I expect to get out of it...
is
> 100ah the total battery capacity or it's useable/available capacity. My
> understanding is that a normal lead acid battery shouldn't be run too
flat,
> so when is flat too flat? If I should only let my battery drain down to
say
> a 90% charge, have I only got 10ah before I need to recharge?
>
>




16 Jun 2004 14:53:46
Stefan
Re: How much power is in a 100ah battery

In article <10d0glvlak4hrda@corp.supernews.com >,
ddotsonNOSPAM@cablespeed.com says...
> 100AH is its total capacity. Normal rule of thumb is to only
> discharge it down to 50%. So, you have 50AH of useful
> capacity.

The advice for NiCad batteries for mobiles etc. is that it is good for
them to go through complete discharge-recharge cycles. Anyone able to
explain why lead/acid batteries are different - if indeed they are?


16 Jun 2004 16:23:06
Jürgen Spelter
Re: How much power is in a 100ah battery

Hi Nigel,

it depends on the type of battery, you are using:

automotive batteries are made for short high current during starting, they
should not been discharged more than 60...80%. In your case 80 AH
discharging will be critical.

marine batteries are made for slow and long discharging and they should not
been discharged too much. Gel batteries should not been discharged more than
60 %, wet batteries not mote than 80 %.

Take a look at the voltage, if you have a digital meter: battery voltage
lower than 10.8 V will damage the battery (deep discharging).

regards

Juergen

"Nigel" <jassira53@hotmail.com > schrieb im Newsbeitrag
news:40d03da0$0$4586$db0fefd9@news.zen.co.uk...
> Stupid question time...
> If I have a 100ah battery how much power can I expect to get out of it...
is
> 100ah the total battery capacity or it's useable/available capacity. My
> understanding is that a normal lead acid battery shouldn't be run too
flat,
> so when is flat too flat? If I should only let my battery drain down to
say
> a 90% charge, have I only got 10ah before I need to recharge?
>
>




16 Jun 2004 15:22:28
Tony Brooks
Re: How much power is in a 100ah battery


"Doug Dotson" <ddotsonNOSPAM@cablespeed.com > wrote in message
news:10d0glvlak4hrda@corp.supernews.com...
> 100AH is its total capacity. Normal rule of thumb is to only
> discharge it down to 50%. So, you have 50AH of useful
> capacity.
>
> Doug
> s/v Callista
>

Not quiet. Lets assume lead acid batteries and only engine charging.

Yes the 50% of discharge is a generally acceptable figure, but you are
unlikley to get them much above 80% of fully charged because we tend to use
automotive alternator regulator designs that are built down to a price and
not up to a duty (they do the job very well on a car).

This means that you can only reliably assume 30% of usable capacity. The
problem is that over the winter that 20% between 80% and 100% of fully
charged will sulphate, which further reduces the capacity of the battery.

To overcome this either charge with a mains charger that can charge to 100%
or fit an advanced regulator that may reach 98% of fully charged.

Tony Brooks


> "Nigel" <jassira53@hotmail.com> wrote in message
> news:40d03da0$0$4586$db0fefd9@news.zen.co.uk...
> > Stupid question time...
> > If I have a 100ah battery how much power can I expect to get out of
it...
> is
> > 100ah the total battery capacity or it's useable/available capacity. My
> > understanding is that a normal lead acid battery shouldn't be run too
> flat,
> > so when is flat too flat? If I should only let my battery drain down to
> say
> > a 90% charge, have I only got 10ah before I need to recharge?
> >
> >
>
>




16 Jun 2004 15:31:13
Tony Brooks
Re: How much power is in a 100ah battery


"Stefan" <dont@spam.me > wrote in message
news:capivf$3gs$1$8300dec7@news.demon.co.uk...
> In article <10d0glvlak4hrda@corp.supernews.com>,
> ddotsonNOSPAM@cablespeed.com says...
> > 100AH is its total capacity. Normal rule of thumb is to only
> > discharge it down to 50%. So, you have 50AH of useful
> > capacity.
>
> The advice for NiCad batteries for mobiles etc. is that it is good for
> them to go through complete discharge-recharge cycles. Anyone able to
> explain why lead/acid batteries are different - if indeed they are?

I think - and it is only think, that it is to do with how the plates are
constructed and move when they afre accepting or delivering high current
flows.

A lead acid battery has its plates made of a grid of lead latice upon which
lead oxide powder is compressed, a bit like plastering a wall.

When high currents are passed the plates actuall flex, the higher the
current the greater the flex. Domestic batteries tend to have thick plates
to give capacity, this means that when they flex the outer particles of the
oxide are compressed or streached so tend to fall off. When they build up in
the bottom of the cell and short a pos. & neg. plate the battery has failed.

The flatter the battery the higher the charging current it will accept for
any given charging voltage, so the more teh plates flex and the more they
shed oxide.

This explanation does for me, although there may be chemical one as well.
This also explains why tubular plates (being curved so resisting flexing)
tend to have a longer life than "normal" flat plate batteries.

Tony Brooks




16 Jun 2004 10:34:33
Glenn Ashmore
Re: How much power is in a 100ah battery

NiCads develop a memory over time and can't be fully recharged unless
they are fully discharged occasionally. Lead acid batteries don't
develop a memory but do start to shed lead from the plates when they get
very low.

As a practical matter you really can't get more than about 35-40% of a
wet cell's capacity out of a normal cycle while cruising. They should
not be discharged more than 50 to 60% and when recharging that last
10-15% takes a long time. Up to about 80% you can safely push 25% of
the capacity per hour back in but above that the rate of charge drops
quickly.

Stefan wrote:
> In article <10d0glvlak4hrda@corp.supernews.com>,
> ddotsonNOSPAM@cablespeed.com says...
>
>>100AH is its total capacity. Normal rule of thumb is to only
>>discharge it down to 50%. So, you have 50AH of useful
>>capacity.
>
>
> The advice for NiCad batteries for mobiles etc. is that it is good for
> them to go through complete discharge-recharge cycles. Anyone able to
> explain why lead/acid batteries are different - if indeed they are?

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com



16 Jun 2004 11:09:23
Guy Fawkes
Re: How much power is in a 100ah battery

Nigel wrote:

> Stupid question time...
> If I have a 100ah battery how much power can I expect to get out of it...
> is 100ah the total battery capacity or it's useable/available capacity. My
> understanding is that a normal lead acid battery shouldn't be run too
> flat, so when is flat too flat? If I should only let my battery drain down
> to say a 90% charge, have I only got 10ah before I need to recharge?

batteries are USUALLY rated on a 10 hour cycle, so a brand new and fully
charged 100Ah battery with put out 10 A for 10 hours, a 60 Ah battery will
put out 6 A for 10 hours, and so on.

The vast majority of batteries, eg car / domestic type, eg NOT deep cycle
type as fitted to fork lifts and milk floats, will die VERY quickly if you
deep cycle them, losing as much as 5% of their total capacity every time
they are deep cycled, so a 2 year old 100 Ah battery that has not been deep
cycled but has been used for engine starting may only have 75 Ah capacity
left, given this I personally rate a 100 Ah battery as a 50 Ah battery to
take this into account.

Others are sure to disagree.
--
Liquid Cooled PC? -- > http://www.surfbaud.co.uk/

E-mail (rot-13) qnirahyy NG oyhrlbaqre QBG pb QBG hx
EoF



16 Jun 2004 17:55:57
Keith Lewis
Re: How much power is in a 100ah battery

In message <capivf$3gs$1$8300dec7@news.demon.co.uk >, Stefan
<dont@spam.me > writes
>In article <10d0glvlak4hrda@corp.supernews.com>,
>ddotsonNOSPAM@cablespeed.com says...
>> 100AH is its total capacity. Normal rule of thumb is to only
>> discharge it down to 50%. So, you have 50AH of useful
>> capacity.
>
>The advice for NiCad batteries for mobiles etc. is that it is good for
>them to go through complete discharge-recharge cycles.

Only applies where a critical cut-off voltage is involved for the
equipment. Otherwise "memory" is an urban myth

>Anyone able to
>explain why lead/acid batteries are different - if indeed they are?

Tend to have steeper discharge curves and be used in non voltage
critical applications

--
Keith Lewis


16 Jun 2004 11:58:34
Steve Alexanderson
Re: How much power is in a 100ah battery

Power is the time rate of energy use. Asking how much power is in a battery
is like asking how much velocity is in a full can of gasoline. There is no
limit implied by the spec quoted.

The Ah spec is usually given at the 20hr rate which is the time to discharge
the battery to 1.75 V/cell (lead acid battery assumed) with a steady current
draw, 5 amps in this case. For a 12 V battery this equates to 10.5 V. It is
a non-linear relationship, halving the current will not double the discharge
time. Battery manufacturers can provide curves or charts that show the
actual Ah for different current draws. The spec is intended to represent
usable capacity, since a battery can be recharged from 1.75V/cell with
little loss of life. Deeper discharges will shorten life. Not too many real
world loads are constant current. Lights will use less current as voltage
drops (constant resistance), motors will use more (constant power.)


"Nigel" <jassira53@hotmail.com > wrote in message
news:40d03da0$0$4586$db0fefd9@news.zen.co.uk...
> Stupid question time...
> If I have a 100ah battery how much power can I expect to get out of it...
is
> 100ah the total battery capacity or it's useable/available capacity. My
> understanding is that a normal lead acid battery shouldn't be run too
flat,
> so when is flat too flat? If I should only let my battery drain down to
say
> a 90% charge, have I only got 10ah before I need to recharge?
>
>




16 Jun 2004 21:17:14
Cerumen
Re: How much power is in a 100ah battery


"Nigel" <jassira53@hotmail.com > wrote in message
news:40d03da0$0$4586$db0fefd9@news.zen.co.uk...
> Stupid question time...
> If I have a 100ah battery how much power can I expect to get out of
it... is
> 100ah the total battery capacity or it's useable/available capacity. My
> understanding is that a normal lead acid battery shouldn't be run too
flat,
> so when is flat too flat? If I should only let my battery drain down to
say
> a 90% charge, have I only got 10ah before I need to recharge?
>
As a very basic answer, a 100 amp/hour battery should provide 100 amps for
an hour or 1 amp for 100 hours, in reality of course it would probably
melt if required to do the former. Then you need to factor in age, type of
use, deep charge trickle or whatever. At best it is a guide only as to the
possible maximum the battery can provide.







16 Jun 2004 22:03:12
Ian Sandell
Re: How much power is in a 100ah battery

On Wed, 16 Jun 2004 21:17:14 +0100, "Cerumen"
<spammers.are.low.life.scum@invalid.com > wrote:

>
>"Nigel" <jassira53@hotmail.com> wrote in message
>news:40d03da0$0$4586$db0fefd9@news.zen.co.uk...
>> Stupid question time...
>> If I have a 100ah battery how much power can I expect to get out of
>it... is
>> 100ah the total battery capacity or it's useable/available capacity. My
>> understanding is that a normal lead acid battery shouldn't be run too
>flat,
>> so when is flat too flat? If I should only let my battery drain down to
>say
>> a 90% charge, have I only got 10ah before I need to recharge?
>>
>As a very basic answer, a 100 amp/hour battery should provide 100 amps for
>an hour or 1 amp for 100 hours, in reality of course it would probably
>melt if required to do the former. Then you need to factor in age, type of
>use, deep charge trickle or whatever. At best it is a guide only as to the
>possible maximum the battery can provide.
>
No. 100 amphour (not amp/hour - that means amps per hour and is quite
different) will be rated at a particular discharge rate - either in
amps or more lilely over a period of time like 10 hours. Discharging
at a different rate wiil give a different capacity. Capacity should
always be quoted at discharge rate, but it's often in the small print.

Ian


16 Jun 2004 22:27:35
Tony
Re: How much power is in a 100ah battery

Ian Sandell wrote:
> On Wed, 16 Jun 2004 21:17:14 +0100, "Cerumen"
> <spammers.are.low.life.scum@invalid.com> wrote:
>
>>
>> "Nigel" <jassira53@hotmail.com> wrote in message
>> news:40d03da0$0$4586$db0fefd9@news.zen.co.uk...
>>> Stupid question time...
>>> If I have a 100ah battery how much power can I expect to get out of
>>> it... is 100ah the total battery capacity or it's useable/available
>>> capacity. My understanding is that a normal lead acid battery
>>> shouldn't be run too flat, so when is flat too flat? If I should
>>> only let my battery drain down to say a 90% charge, have I only got
>>> 10ah before I need to recharge?
>>>
>> As a very basic answer, a 100 amp/hour battery should provide 100
>> amps for an hour or 1 amp for 100 hours, in reality of course it
>> would probably melt if required to do the former. Then you need to
>> factor in age, type of use, deep charge trickle or whatever. At best
>> it is a guide only as to the possible maximum the battery can
>> provide.
>>
> No. 100 amphour (not amp/hour - that means amps per hour and is quite
> different) will be rated at a particular discharge rate - either in
> amps or more lilely over a period of time like 10 hours. Discharging
> at a different rate wiil give a different capacity. Capacity should
> always be quoted at discharge rate, but it's often in the small print.
>

What's the CCA rating mean?

Tony




16 Jun 2004 22:58:33
Ian Sandell
Re: How much power is in a 100ah battery

On Wed, 16 Jun 2004 22:27:35 +0100, "Tony" <Rodney@10uk.net > wrote:

>Ian Sandell wrote:
snip.
>>>
>> No. 100 amphour (not amp/hour - that means amps per hour and is quite
>> different) will be rated at a particular discharge rate - either in
>> amps or more lilely over a period of time like 10 hours. Discharging
>> at a different rate wiil give a different capacity. Capacity should
>> always be quoted at discharge rate, but it's often in the small print.
>>
>
>What's the CCA rating mean?
>
>Tony
>
Cold cranking amps. I'm no expert but I understand that this is a
measure of high current, short duration ability, eg for starting,
rather than capacity rating. I dont know the definition (if there is
one) but suspect it's something like max amps for so many secs at
battery temp Cdeg without battery output voltage falling below V
Volts.

Ian


16 Jun 2004 23:36:04
Andy Champ
Re: How much power is in a 100ah battery

Guy Fawkes wrote:
>
<snip >
> ...so a 2 year old 100 Ah battery that has not been deep
> cycled but has been used for engine starting may only have 75 Ah capacity
> left...
<snip more >

Guy, you may be being pessimistic. My last car was scrapped complete
with original (working) battery after 8 years & 120,000 miles. If I had
lost 25% in 2 years, after 8 years I'd only have 30% left. Yet it
cranked fine - even when periodically I forgot to turn the immobiliser
off so it didn't fire...
Then again, I may have been lucky.

Andy.



16 Jun 2004 23:51:44
Jeff Richards
Re: How much power is in a 100ah battery

Ah capacity is only slightly related to cranking ability. A battery can be
significantly down on it's rated capacity yet still able to deliver adequate
voltage for the typical period needed for starting an engine, even with the
immobiliser.
--

"Andy Champ" <no.way@nospam.com > wrote in message
news:40d0cb3c$0$20514$cc9e4d1f@news-text.dial.pipex.com...
> Guy Fawkes wrote:
>>
> <snip>
>> ...so a 2 year old 100 Ah battery that has not been deep
>> cycled but has been used for engine starting may only have 75 Ah capacity
>> left...
> <snip more>
>
> Guy, you may be being pessimistic. My last car was scrapped complete with
> original (working) battery after 8 years & 120,000 miles. If I had lost
> 25% in 2 years, after 8 years I'd only have 30% left. Yet it cranked
> fine - even when periodically I forgot to turn the immobiliser off so it
> didn't fire...
> Then again, I may have been lucky.
>
> Andy.
>




17 Jun 2004 00:00:26
Lyndon Nerenberg
Re: How much power is in a 100ah battery

Andy Champ <no.way@nospam.com > writes:

>Guy Fawkes wrote:
>> ...so a 2 year old 100 Ah battery that has not been deep
>> cycled but has been used for engine starting may only have 75 Ah capacity
>> left...

>Guy, you may be being pessimistic. My last car was scrapped complete
>with original (working) battery after 8 years & 120,000 miles. If I had
>lost 25% in 2 years, after 8 years I'd only have 30% left. Yet it
>cranked fine - even when periodically I forgot to turn the immobiliser
>off so it didn't fire...

He was talking about deep-cycle batteries. They are not designed for
extremely high current draw applications (such as engine starting).
Just like starting batteries are not designed to be drawn way down.
The difference is due to the plate design. A plate designed for
providing cranking amps isn't good for deep cycle applications,
and vice versa.

Head to your local library and see if they have a copy of
_Boatowner's Mechanical and Electrical Manual_ by Nigel
Calder. The introduction in chapter one gives an excellent
description of the difference between the two battery types.

In fact, this is a "must own" book for any cruiser. I paid
$80 (Canadian) for mine (second edition hardcover) and it was
worth every penny.

--lyndon


17 Jun 2004 07:39:08
Tony
Re: How much power is in a 100ah battery

Ian Sandell wrote:
> On Wed, 16 Jun 2004 22:27:35 +0100, "Tony" <Rodney@10uk.net> wrote:
>
>> Ian Sandell wrote:
> snip.
>>>>
>>> No. 100 amphour (not amp/hour - that means amps per hour and is
>>> quite different) will be rated at a particular discharge rate -
>>> either in amps or more lilely over a period of time like 10 hours.
>>> Discharging at a different rate wiil give a different capacity.
>>> Capacity should always be quoted at discharge rate, but it's often
>>> in the small print.
>>>
>>
>> What's the CCA rating mean?
>>
>> Tony
>>
> Cold cranking amps. I'm no expert but I understand that this is a
> measure of high current, short duration ability, eg for starting,
> rather than capacity rating. I dont know the definition (if there is
> one) but suspect it's something like max amps for so many secs at
> battery temp Cdeg without battery output voltage falling below V
> Volts.
>

Thank you.




17 Jun 2004 08:53:55
Tony Brooks
Re: How much power is in a 100ah battery


"Ian Sandell" <ian@sandell.co.uk > wrote in message
news:hbg1d0he69nkrvrckc76aj1sekav1oest3@4ax.com...
> On Wed, 16 Jun 2004 22:27:35 +0100, "Tony" <Rodney@10uk.net> wrote:
>
> >Ian Sandell wrote:
> snip.
> >>>
> >> No. 100 amphour (not amp/hour - that means amps per hour and is quite
> >> different) will be rated at a particular discharge rate - either in
> >> amps or more lilely over a period of time like 10 hours. Discharging
> >> at a different rate wiil give a different capacity. Capacity should
> >> always be quoted at discharge rate, but it's often in the small print.
> >>
> >
> >What's the CCA rating mean?
> >
> >Tony
> >
> Cold cranking amps. I'm no expert but I understand that this is a
> measure of high current, short duration ability, eg for starting,
> rather than capacity rating. I dont know the definition (if there is
> one) but suspect it's something like max amps for so many secs at
> battery temp Cdeg without battery output voltage falling below V
> Volts.
>
> Ian

Exactly so

But I can not get my hand on the exact definition. at the moment, but in any
cas ethis is only applicable to Starting battteries.

There is also Reserve Capacity. This indcates how long, in minutes, at 25C,
the battery will deliver 25 amps before the cell votage drops to
1.75v.

I have only seen this written on vehicle batteries.

Tony Brooks




17 Jun 2004 10:12:23
martin
Re: How much power is in a 100ah battery

On Wed, 16 Jun 2004 23:36:04 +0000, Andy Champ <no.way@nospam.com >
wrote:

>Guy Fawkes wrote:
>>
><snip>
>> ...so a 2 year old 100 Ah battery that has not been deep
>> cycled but has been used for engine starting may only have 75 Ah capacity
>> left...
><snip more>
>
>Guy, you may be being pessimistic. My last car was scrapped complete
>with original (working) battery after 8 years & 120,000 miles. If I had
>lost 25% in 2 years, after 8 years I'd only have 30% left. Yet it
>cranked fine - even when periodically I forgot to turn the immobiliser
>off so it didn't fire...
>Then again, I may have been lucky.

I have a 9 year old Nissan Primera still running on it's original
battery.
--
Martin


17 Jun 2004 10:17:21
martin
Re: How much power is in a 100ah battery

On Thu, 17 Jun 2004 00:00:26 -0000, Lyndon Nerenberg
<lyndon@orthanc.ca > wrote:

>Andy Champ <no.way@nospam.com> writes:
>
>>Guy Fawkes wrote:
>>> ...so a 2 year old 100 Ah battery that has not been deep
>>> cycled but has been used for engine starting may only have 75 Ah capacity
>>> left...
>
>>Guy, you may be being pessimistic. My last car was scrapped complete
>>with original (working) battery after 8 years & 120,000 miles. If I had
>>lost 25% in 2 years, after 8 years I'd only have 30% left. Yet it
>>cranked fine - even when periodically I forgot to turn the immobiliser
>>off so it didn't fire...
>
>He was talking about deep-cycle batteries. They are not designed for
>extremely high current draw applications (such as engine starting).
>Just like starting batteries are not designed to be drawn way down.
>The difference is due to the plate design. A plate designed for
>providing cranking amps isn't good for deep cycle applications,
>and vice versa.
>
>Head to your local library and see if they have a copy of
>_Boatowner's Mechanical and Electrical Manual_ by Nigel
>Calder. The introduction in chapter one gives an excellent
>description of the difference between the two battery types.
>
>In fact, this is a "must own" book for any cruiser. I paid
>$80 (Canadian) for mine (second edition hardcover) and it was
>worth every penny.

There's a copy going for GBP25 at http://www.abebooks.co.uk
--
Martin


17 Jun 2004 08:38:04
Peter W. Meek
Re: How much power is in a 100ah battery

On Wed, 16 Jun 2004 10:34:33 -0400, Glenn Ashmore <gashmore3@cox.net >
wrote:

>NiCads develop a memory over time and can't be fully recharged unless
>they are fully discharged occasionally.

This is (almost) a myth. The Ni-Cad memory phenomenon
does exist, but I can almost promise that no-one
reading this has ever experienced it. It requires
that the partial discharge/charge cycle be repeated
*****EXACTLY***** many, many times. It was discovered
in a satellite (and eventually duplicated) where the
battery discharged for a precise length of time into
a precise load, and then was recharged for a precise
length of time at a precise rate. When the program
of the satellite was changed later, it was found that
the battery could not continue providing power after
passing the previous discharge point.

It simply won't happen just because you don't run
a Ni-Cad down to zero before recharging it. In
fact if you DO run it to zero, there is a very good
chance that (because of slight differences in cell
capacity) that you will reverse-charge one or more
of the cells, which WILL ruin that cell quickly.
Better to get it onto the recharger as soon as
you experience a significant drop in output
under load. At the point where your battery drill
stalls at no load or very light load, you may well
be pumping up one of the cells backwards as the
other cells push the last few electrons through
the load.

The commonest way to damage Ni-cads, however, is to
leave them on the charger too long, or to charge
them too fast at some point in the recharge cycle.
Every time this happens, the battery will lose
some of it's capacity.



17 Jun 2004 15:38:36
taz
Re: How much power is in a 100ah battery


"Peter W. Meek" <pwmeek@mail.msen.com > wrote in message
news:c233d01m92pq2poddu8bm01ojsnctl3upp@4ax.com...
> On Wed, 16 Jun 2004 10:34:33 -0400, Glenn Ashmore <gashmore3@cox.net>
> wrote:
>
> >NiCads develop a memory over time and can't be fully recharged unless
> >they are fully discharged occasionally.
>
> This is (almost) a myth. The Ni-Cad memory phenomenon
> does exist, but I can almost promise that no-one
> reading this has ever experienced it. It requires
> that the partial discharge/charge cycle be repeated
> *****EXACTLY***** many, many times. It was discovered
> in a satellite (and eventually duplicated) where the
> battery discharged for a precise length of time into
> a precise load, and then was recharged for a precise


I Beg to differ with you.
I have on occasions, and know friends who have damaged
Ni-Cad batteries. They were damaged by partial depletion
then recharging. They were in sealed waterproof torches
and over a period of time the batteries were damaged by
that method of charging. I now always run my batteries from
full to empty no mater what type.
taz.




17 Jun 2004 16:40:59
Doug
Re: How much power is in a 100ah battery

I have also seen it happen...running wet cell NiCad's for a back up source
of power for cesium beam frequency standards. These units we periodically
discharged and recharged as a preventative maintenance procedure, and they
did develop memory. The fix was to vary the preventative maintenance
discharge time/amount. H/P factory support helped us solve this problem.
Doug K7ABX
"taz" <taz24taz24@blueyonder.co.uk > wrote in message
news:0WiAc.2748$VB.21788723@news-text.cableinet.net...
>
> "Peter W. Meek" <pwmeek@mail.msen.com> wrote in message
> news:c233d01m92pq2poddu8bm01ojsnctl3upp@4ax.com...
> > On Wed, 16 Jun 2004 10:34:33 -0400, Glenn Ashmore <gashmore3@cox.net>
> > wrote:
> >
> > >NiCads develop a memory over time and can't be fully recharged unless
> > >they are fully discharged occasionally.
> >
> > This is (almost) a myth. The Ni-Cad memory phenomenon
> > does exist, but I can almost promise that no-one
> > reading this has ever experienced it. It requires
> > that the partial discharge/charge cycle be repeated
> > *****EXACTLY***** many, many times. It was discovered
> > in a satellite (and eventually duplicated) where the
> > battery discharged for a precise length of time into
> > a precise load, and then was recharged for a precise
>
>
> I Beg to differ with you.
> I have on occasions, and know friends who have damaged
> Ni-Cad batteries. They were damaged by partial depletion
> then recharging. They were in sealed waterproof torches
> and over a period of time the batteries were damaged by
> that method of charging. I now always run my batteries from
> full to empty no mater what type.
> taz.
>
>




17 Jun 2004 19:27:56
Keith Lewis
Re: How much power is in a 100ah battery

In message <0WiAc.2748$VB.21788723@news-text.cableinet.net >, taz
<taz24taz24@blueyonder.co.uk > writes
>
>"Peter W. Meek" <pwmeek@mail.msen.com> wrote in message
>news:c233d01m92pq2poddu8bm01ojsnctl3upp@4ax.com...
>> On Wed, 16 Jun 2004 10:34:33 -0400, Glenn Ashmore <gashmore3@cox.net>
>> wrote:
>>
>> >NiCads develop a memory over time and can't be fully recharged unless
>> >they are fully discharged occasionally.
>>
>> This is (almost) a myth. The Ni-Cad memory phenomenon
>> does exist, but I can almost promise that no-one
>> reading this has ever experienced it. It requires
>> that the partial discharge/charge cycle be repeated
>> *****EXACTLY***** many, many times. It was discovered
>> in a satellite (and eventually duplicated) where the
>> battery discharged for a precise length of time into
>> a precise load, and then was recharged for a precise
>
>
>I Beg to differ with you.
>I have on occasions, and know friends who have damaged
>Ni-Cad batteries. They were damaged by partial depletion
>then recharging. They were in sealed waterproof torches
>and over a period of time the batteries were damaged by
>that method of charging. I now always run my batteries from
>full to empty no mater what type.
>taz.
>
>
Top-up charging is the best regime for NiCd's used in a torch. Full
discharge every time simply wears out the cells unnecessarily.

Of course cells vary enormously in quality and it is virtually
impossible to buy decent ones from retail outlets.

--
Keith Lewis


17 Jun 2004 22:00:27
Andy Champ
Re: How much power is in a 100ah battery

martin wrote:

> On Wed, 16 Jun 2004 23:36:04 +0000, Andy Champ <no.way@nospam.com>
> wrote:
>>Guy, you may be being pessimistic. My last car was scrapped complete
>>with original (working) battery after 8 years & 120,000 miles. If I had
>>lost 25% in 2 years, after 8 years I'd only have 30% left. Yet it
>>cranked fine - even when periodically I forgot to turn the immobiliser
>>off so it didn't fire...
>>Then again, I may have been lucky.
>
>
> I have a 9 year old Nissan Primera still running on it's original
> battery.

Now there's a coincidence. Mine was a Primera too!

Andy



18 Jun 2004 08:26:05
taz
Re: How much power is in a 100ah battery

> >I Beg to differ with you.
> >I have on occasions, and know friends who have damaged
> >Ni-Cad batteries. They were damaged by partial depletion
> >then recharging. They were in sealed waterproof torches
> >and over a period of time the batteries were damaged by
> >that method of charging. I now always run my batteries from
> >full to empty no mater what type.
> >taz.
> >
> >
> Top-up charging is the best regime for NiCd's used in a torch. Full
> discharge every time simply wears out the cells unnecessarily.
>
> Of course cells vary enormously in quality and it is virtually
> impossible to buy decent ones from retail outlets.
>
> --
> Keith Lewis

I agree Keith there are a lot of variables to batteries and the way
they are charged. The trouble with most set-ups IMHO is one cell
will fail in the battery and then the battery as a unit starts to perform
badly. Good cells are hard to get hold of and can easily be damaged
by incorrect use. In my experience if a cell is sold with the label good for
2000 charge cycles I've found that, that number can be reduced by half
if not even 3/4. So in real terms a battery that should be good for 2000
charges sometimes only last for 500 maybe 1000 charges.
Not a scientific answer just my own experience.
taz.




18 Jun 2004 08:30:44
taz
Re: How much power is in a 100ah battery


"Andy Champ" <no.way@nospam.com > wrote in message
news:40d20653$0$275$cc9e4d1f@news-text.dial.pipex.com...
> martin wrote:
>
> > On Wed, 16 Jun 2004 23:36:04 +0000, Andy Champ <no.way@nospam.com>
> > wrote:
> >>Guy, you may be being pessimistic. My last car was scrapped complete
> >>with original (working) battery after 8 years & 120,000 miles. If I had
> >>lost 25% in 2 years, after 8 years I'd only have 30% left. Yet it
> >>cranked fine - even when periodically I forgot to turn the immobiliser
> >>off so it didn't fire...
> >>Then again, I may have been lucky.
> >
> >
> > I have a 9 year old Nissan Primera still running on it's original
> > battery.
>
> Now there's a coincidence. Mine was a Primera too!
>
> Andy


What you both use the same battery? :-}
taz.




18 Jun 2004 10:57:15
martin
Re: How much power is in a 100ah battery

On Fri, 18 Jun 2004 08:30:44 GMT, "taz" <taz24taz24@blueyonder.co.uk >
wrote:

>
>"Andy Champ" <no.way@nospam.com> wrote in message
>news:40d20653$0$275$cc9e4d1f@news-text.dial.pipex.com...
>> martin wrote:
>>
>> > On Wed, 16 Jun 2004 23:36:04 +0000, Andy Champ <no.way@nospam.com>
>> > wrote:
>> >>Guy, you may be being pessimistic. My last car was scrapped complete
>> >>with original (working) battery after 8 years & 120,000 miles. If I had
>> >>lost 25% in 2 years, after 8 years I'd only have 30% left. Yet it
>> >>cranked fine - even when periodically I forgot to turn the immobiliser
>> >>off so it didn't fire...
>> >>Then again, I may have been lucky.
>> >
>> >
>> > I have a 9 year old Nissan Primera still running on it's original
>> > battery.
>>
>> Now there's a coincidence. Mine was a Primera too!
>>
>> Andy
>
>
>What you both use the same battery? :-}

Where does it say anything like that?
--
Martin


18 Jun 2004 10:01:19
James
Re: How much power is in a 100ah battery


"Peter W. Meek" <pwmeek@mail.msen.com > wrote in message
news:c233d01m92pq2poddu8bm01ojsnctl3upp@4ax.com...
> On Wed, 16 Jun 2004 10:34:33 -0400, Glenn Ashmore <gashmore3@cox.net>
> wrote:
>
> >NiCads develop a memory over time and can't be fully recharged unless
> >they are fully discharged occasionally.
>
> This is (almost) a myth. The Ni-Cad memory phenomenon
> does exist, but I can almost promise that no-one
> reading this has ever experienced it.

I am sorry but you are not entirly correct.

Proven many many times and easy to repeat.
Take two brand new and identical radio controlled racing cars.
FULLY charge and discharge the nicads of one of the cars ten times.
Randomly and gently cycle the nicads of the other car ten times.
Race the cars.

Fully charged/discharged car WILL win.
Not only will the car win a short sprint race... It will also win an
endurance race.







18 Jun 2004 08:47:53
Peter W. Meek
Re: How much power is in a 100ah battery

On Thu, 17 Jun 2004 16:40:59 GMT, "Doug" <dougm@rodgersmarine.com >
wrote:

>I have also seen it happen...running wet cell NiCad's for a back up source
>of power for cesium beam frequency standards. These units we periodically
>discharged and recharged as a preventative maintenance procedure, and they
>did develop memory. The fix was to vary the preventative maintenance
>discharge time/amount. H/P factory support helped us solve this problem.
>Doug K7ABX

Well, I must admit, you ARE one of the very few who
has experienced true "memory" in Ni-Cads. Taz will
have to look elsewhere for his problems with his
sealed waterproof torches. Unless he has found some
way to discharge them partially AND IDENTICALLY each
time (on for the exact same amount of time at the
exact same temperature, EVERY single time) then it
is something else that is reducing the capacity of
his Ni-Cads. (They DO wear out under normal conditions,
just not as soon and with as sharp a cut-off as when
the memory effect is the cause.)



18 Jun 2004 15:04:13
Gary Schafer
Re: How much power is in a 100ah battery

On Fri, 18 Jun 2004 10:01:19 +0000 (UTC), "James"
<jamesenglish4@hotmailnospam.com > wrote:

>
>"Peter W. Meek" <pwmeek@mail.msen.com> wrote in message
>news:c233d01m92pq2poddu8bm01ojsnctl3upp@4ax.com...
>> On Wed, 16 Jun 2004 10:34:33 -0400, Glenn Ashmore <gashmore3@cox.net>
>> wrote:
>>
>> >NiCads develop a memory over time and can't be fully recharged unless
>> >they are fully discharged occasionally.
>>
>> This is (almost) a myth. The Ni-Cad memory phenomenon
>> does exist, but I can almost promise that no-one
>> reading this has ever experienced it.
>
>I am sorry but you are not entirly correct.
>
>Proven many many times and easy to repeat.
>Take two brand new and identical radio controlled racing cars.
>FULLY charge and discharge the nicads of one of the cars ten times.
>Randomly and gently cycle the nicads of the other car ten times.
>Race the cars.
>
>Fully charged/discharged car WILL win.
>Not only will the car win a short sprint race... It will also win an
>endurance race.
>
>
>
>

What you are seeing has nothing to do with "memory effect".
A new nicad cell needs to be exercised several times to bring it up to
its full capacity. The capacity as to charge / discharge cycles is
sort of a bell shaped curve. Brand new not as much, after several
charge discharge cycles the capacity peaks, then it starts declining
with more charge discharge cycles.

When discharging them you should never discharge them below about 1
volt per cell. Doing so you run the risk of a cell being reverse
charged and that is the kiss of death for that cell.

Also nicad's don't like to be float charged like a lead acid battery.
A lead acid battery is as happy as can be when it is properly float
charged. A nicad is not. It will kill them. A nicad is not the proper
battery type for standby power.

Don't let a nicad get too hot when charging as that will cause the
cell to vent. Once a cell vents it is pretty much history.

By the way, there is no such thing as "memory effect". The very early
ni cad cells had sort of that problem but it does not exist in modern
cells.

Regards
Gary


18 Jun 2004 17:00:22
Stefan
Re: How much power is in a 100ah battery

In article <t216d0l444lqnlmtgsqqvh520rertbodmb@4ax.com >,
gaschafer@comcast.net says...

> Also nicad's don't like to be float charged like a lead acid battery.

What does "float-charged" mean?


18 Jun 2004 18:09:13
Gary Schafer
Re: How much power is in a 100ah battery

On Fri, 18 Jun 2004 17:00:22 +0100, Stefan <dont@spam.me > wrote:

>In article <t216d0l444lqnlmtgsqqvh520rertbodmb@4ax.com>,
>gaschafer@comcast.net says...
>
>> Also nicad's don't like to be float charged like a lead acid battery.
>
>What does "float-charged" mean?

"Floating a battery" refers to keeping a constant voltage charge on
the battery that is just high enough to replace the natural losses in
the battery. This is typically done with lead acid batteries that are
to be maintained at peak charge but not used for long periods.

A fully charged 12 volt lead acid battery has a voltage of around 12.7
volts. It will slowly discharge itself with no load on it if left
alone.
If a constant 13.3 to 13.6 volts (depending on temperature) charge is
left on the battery it will replace the self discharge energy of the
battery. This voltage can be left on the battery indefinitely and will
not harm the battery. Any higher charge voltage, only by a few tenths
of a volt, for long periods will harm the battery.

When initially charging the battery the voltage needs to be at around
14.2 volts for finishing the charge. Some gassing of the battery needs
to take place in the final phase of charging, slight overcharging, in
order to properly top off the cells. Then switch to the float voltage
13.3 volts to maintain.

Regards
Gary


19 Jun 2004 14:26:29
taz
Re: How much power is in a 100ah battery

> >What you both use the same battery? :-}
>
> Where does it say anything like that?
> --
> Martin

I was Joking Martin hence the smiley face.
But forget it I won't bother you again.
taz.




20 Jun 2004 13:07:07
Larry W4CSC
Re: How much power is in a 100ah battery

"Doug" <dougm@rodgersmarine.com > wrote in
news:vQjAc.8303$Wr.1083@newsread1.news.pas.earthlink.net:

> I have also seen it happen...running wet cell NiCad's for a back up
> source of power for cesium beam frequency standards. These units we
> periodically discharged and recharged as a preventative maintenance
> procedure, and they did develop memory. The fix was to vary the
> preventative maintenance discharge time/amount. H/P factory support
> helped us solve this problem. Doug K7ABX

I remember that in HP freq standards, too, Doug.

What lab do/did you work in? I'm a metrologist, too.

Larry W4CSC

Metrology Engineering Center (Code 132)
Quality Assurance Office
Charleston Naval Shipyard
(may she rest in peace)


21 Jun 2004 09:12:34
Keith Lewis
Re: How much power is in a 100ah battery

In message <xGxAc.3564$S51.30959848@news-text.cableinet.net >, taz
<taz24taz24@blueyonder.co.uk > writes
>> >I Beg to differ with you.
>> >I have on occasions, and know friends who have damaged
>> >Ni-Cad batteries. They were damaged by partial depletion
>> >then recharging. They were in sealed waterproof torches
>> >and over a period of time the batteries were damaged by
>> >that method of charging. I now always run my batteries from
>> >full to empty no mater what type.
>> >taz.
>> >
>> >
>> Top-up charging is the best regime for NiCd's used in a torch. Full
>> discharge every time simply wears out the cells unnecessarily.
>>
>> Of course cells vary enormously in quality and it is virtually
>> impossible to buy decent ones from retail outlets.
>>
>> --
>> Keith Lewis
>
>I agree Keith there are a lot of variables to batteries and the way
>they are charged. The trouble with most set-ups IMHO is one cell
>will fail in the battery and then the battery as a unit starts to perform
>badly. Good cells are hard to get hold of and can easily be damaged
>by incorrect use. In my experience if a cell is sold with the label good for
>2000 charge cycles I've found that, that number can be reduced by half
>if not even 3/4. So in real terms a battery that should be good for 2000
>charges sometimes only last for 500 maybe 1000 charges.
>Not a scientific answer just my own experience.
>taz.
>
>
Agreed

Cells are extremely variable and the ones on retail sale tend to give
good ones a bad name. Many are in "D" size cases but are only around
1200 mAH as opposed to an average of 4000 mAH for those available to
OEM's

We've been manufacturing NiCd powered lighting for over 20 years and
have been giving a 3 year guarantee for that time. We do however fit
rather good ones:-)
--
Keith Lewis


21 Jun 2004 10:03:46
taz
Re: How much power is in a 100ah battery

> Agreed
>
> Cells are extremely variable and the ones on retail sale tend to give
> good ones a bad name. Many are in "D" size cases but are only around
> 1200 mAH as opposed to an average of 4000 mAH for those available to
> OEM's
>
> We've been manufacturing NiCd powered lighting for over 20 years and
> have been giving a 3 year guarantee for that time. We do however fit
> rather good ones:-)
> --
> Keith Lewis

If I need NiCad cells now I use the ones that power
emergency lights. They come pre-made into batteries
and do seem to be of higher quality.
taz.




21 Jun 2004 19:17:10
Keith Lewis
Re: How much power is in a 100ah battery

In message <6oyBc.1638$YY4.14442613@news-text.cableinet.net >, taz
<taz24taz24@blueyonder.co.uk > writes
>> Agreed
>>
>> Cells are extremely variable and the ones on retail sale tend to give
>> good ones a bad name. Many are in "D" size cases but are only around
>> 1200 mAH as opposed to an average of 4000 mAH for those available to
>> OEM's
>>
>> We've been manufacturing NiCd powered lighting for over 20 years and
>> have been giving a 3 year guarantee for that time. We do however fit
>> rather good ones:-)
>> --
>> Keith Lewis
>
>If I need NiCad cells now I use the ones that power
>emergency lights. They come pre-made into batteries
>and do seem to be of higher quality.
>taz.
>
>
They tend to be "high temperature" versions (gets warm in emergency
lighting luminaires) so separator design has to be good. Dendritic
crystal growth through separators is the usual failure mode of Nicd's


--
Keith Lewis


22 Jun 2004 01:12:46
taz
Re: How much power is in a 100ah battery

> They tend to be "high temperature" versions (gets warm in emergency
> lighting luminaires) so separator design has to be good. Dendritic
> crystal growth through separators is the usual failure mode of Nicd's
>
>
> --
> Keith Lewis

Is that a white powdery substance. Or I'm I just
thinking of corrosion that forms on the aluminium
casing sometimes.
taz.




22 Jun 2004 08:41:44
Keith Lewis
Re: How much power is in a 100ah battery

In message <iILBc.2447$Ag4.21565619@news-text.cableinet.net >, taz
<taz24taz24@blueyonder.co.uk > writes
>> They tend to be "high temperature" versions (gets warm in emergency
>> lighting luminaires) so separator design has to be good. Dendritic
>> crystal growth through separators is the usual failure mode of Nicd's
>>
>>
>> --
>> Keith Lewis
>
>Is that a white powdery substance. Or I'm I just
>thinking of corrosion that forms on the aluminium
>casing sometimes.
>taz.
>
>
No its internal and causes tiny short circuits through the separator.
Eventually these raise the self-discharge rate to unmanageable
proportions ( but you will probably find that straight off charge you
still get sufficient capacity).

The cases are nickel plated steel
--
Keith Lewis


22 Jun 2004 10:58:05
taz
Re: How much power is in a 100ah battery

> No its internal and causes tiny short circuits through the separator.
> Eventually these raise the self-discharge rate to unmanageable
> proportions ( but you will probably find that straight off charge you
> still get sufficient capacity).
>
> The cases are nickel plated steel
> --
> Keith Lewis

Right I must be getting confused then :-)
Not hard I suppose. I understand what you
are saying about the internal circuits now and
as for the casing I obviously can't tell my nickel
from my ally. Thinking back though and this is me
trying to scratch back some resemblance of intelligence,
our batteries were placed in aluminium bodied torches
and with the added ingredient of see water it could of
been that environment that was causing the corrosion
inside the inside the torch and on the battery.

Well that theory makes sense to me. Yeah good one
taz. taz slinks of congratulating him self on how he
pulled it back without any one noticing. ;-)
Cheers taz.




22 Jun 2004 04:48:35
Jens K
Using car battery in boat for limited time (was:How much power is in a 100ah battery)

> As a very basic answer, a 100 amp/hour battery should provide 100 amps for
> an hour or 1 amp for 100 hours, in reality of course it would probably
> melt if required to do the former. Then you need to factor in age, type of
> use, deep charge trickle or whatever. At best it is a guide only as to the
> possible maximum the battery can provide.

As I normally daysail I do not need a battery in my boat. But when I
occasionally cruise for a few days, I would like one, but only for the
lights. I do not have other power consuming devices in my boat.

So now the question is this: could I simply move my car's battery to
the boat? Let's say for a four days cruise during summer time. Will it
still start the car afterwards? I guess there will be the pleasant
side-effect that the car will be less likely to be stolen.


22 Jun 2004 13:22:49
Tony Brooks
Re: Using car battery in boat for limited time (was:How much power is in a 100ah battery)


"Jens K" <jenku@yahoo.com > wrote in message
news:d5988190.0406220348.488d14d8@posting.google.com...
> > As a very basic answer, a 100 amp/hour battery should provide 100 amps
for
> > an hour or 1 amp for 100 hours, in reality of course it would probably
> > melt if required to do the former. Then you need to factor in age, type
of
> > use, deep charge trickle or whatever. At best it is a guide only as to
the
> > possible maximum the battery can provide.
>
> As I normally daysail I do not need a battery in my boat. But when I
> occasionally cruise for a few days, I would like one, but only for the
> lights. I do not have other power consuming devices in my boat.
>
> So now the question is this: could I simply move my car's battery to
> the boat? Let's say for a four days cruise during summer time. Will it
> still start the car afterwards? I guess there will be the pleasant
> side-effect that the car will be less likely to be stolen.

Please do a power audit (www.reading-college.ac.uk/marine) under course
notes. This will tell you exactly how much electricity you need to store.

Then decide if teh battery will still have enough capacity left to start the
car in adverse conditions (my guess is no).

If you do decide to go ahead with your proposed plan, please be aware that a
car battery is constructed differently to those designed for the use you
have in mind and you will shorten its life. If it is going to be by a
measurable amount, I have no idea, butw ould not take the risk.

I suspect a small leasure battery from a caravan shop and a split charge
relay for the car (from the same source) would be your best bet. You could
even just run a wire from the ignition switch to a croc clip in the boot to
recharge the leasure battery whilst driving.

Tony Brooks




22 Jun 2004 08:31:14
Vito
Re: Using car battery in boat for limited time (was:How much power is in a 100ah battery)

"Jens K" <jenku@yahoo.com > wrote
> So now the question is this: could I simply move my car's battery to
> the boat? Let's say for a four days cruise during summer time. Will it
> still start the car afterwards? I guess there will be the pleasant
> side-effect that the car will be less likely to be stolen.

It'd be like leaving your car's interior lights on for four days. Would the
car still start? Probably, but maybe not. (Mine didn't, leaving me stuck).
Would the battery's life be shortened? Probably, but maybe not.




22 Jun 2004 10:42:31
Glenn Ashmore
Re: Using car battery in boat for limited time

Bad idea. Car batteries are designed to produce a lot of power for a
few seconds and then be immediately recharged. They can survive being
deeply discharged maybe 5 or 6 times before they die.

Assuming you have a 25 watt anchor light burning 8 hours. That is 16
AH. Then you have 3 10 watt cabin lights burning 4 hours. That is 10
AH. Over a three night weekend that is about 75 AH. That will kill a
group 27 auto battery in short order. You need 150 AH of battery minumum.

The cheapest and longest lasting route would be a pair of $50 golf cart
batteries from Wallymart, Sam's or Costco and a $60 charger with auto
shutoff from Harbor Freight. You will eat that much in car batteries in
one season.

Jens K wrote:

> As I normally daysail I do not need a battery in my boat. But when I
> occasionally cruise for a few days, I would like one, but only for the
> lights. I do not have other power consuming devices in my boat.
>
> So now the question is this: could I simply move my car's battery to
> the boat? Let's say for a four days cruise during summer time. Will it
> still start the car afterwards? I guess there will be the pleasant
> side-effect that the car will be less likely to be stolen.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com



22 Jun 2004 17:33:54
Keith Lewis
Re: How much power is in a 100ah battery

In message <1hUBc.2660$HO.23609499@news-text.cableinet.net >, taz
<taz24taz24@blueyonder.co.uk > writes
>> No its internal and causes tiny short circuits through the separator.
>> Eventually these raise the self-discharge rate to unmanageable
>> proportions ( but you will probably find that straight off charge you
>> still get sufficient capacity).
>>
>> The cases are nickel plated steel
>> --
>> Keith Lewis
>
>Right I must be getting confused then :-)
>Not hard I suppose. I understand what you
>are saying about the internal circuits now and
>as for the casing I obviously can't tell my nickel
>from my ally. Thinking back though and this is me
>trying to scratch back some resemblance of intelligence,
>our batteries were placed in aluminium bodied torches
>and with the added ingredient of see water it could of
>been that environment that was causing the corrosion
>inside the inside the torch and on the battery.
>
>Well that theory makes sense to me. Yeah good one
>taz. taz slinks of congratulating him self on how he
>pulled it back without any one noticing. ;-)
>Cheers taz.
>
>
Sounds an excellent corrosive cocktail

Cheers
--
Keith Lewis


22 Jun 2004 18:58:59
taz
Re: How much power is in a 100ah battery

>Well that theory makes sense to me. Yeah good one
> >taz. taz slinks of congratulating him self on how he
> >pulled it back without any one noticing. ;-)
> >Cheers taz.
> >
> >
> Sounds an excellent corrosive cocktail
>
> Cheers
> --
> Keith Lewis

Yes quite a stressful environment for the batteries I suppose.
taz.




22 Jun 2004 20:48:14
John Wilson
Re: Using car battery in boat for limited time (was:How much power is in a 100ah battery)

On 22 Jun 2004 04:48:35 -0700, jenku@yahoo.com (Jens K) wrote:

>> As a very basic answer, a 100 amp/hour battery should provide 100 amps for
>> an hour or 1 amp for 100 hours, in reality of course it would probably
>> melt if required to do the former. Then you need to factor in age, type of
>> use, deep charge trickle or whatever. At best it is a guide only as to the
>> possible maximum the battery can provide.
>
>As I normally daysail I do not need a battery in my boat. But when I
>occasionally cruise for a few days, I would like one, but only for the
>lights. I do not have other power consuming devices in my boat.
>
In the same situation many years ago (very impoverished) I bought a
newer secondhand battery for my ancient car and put the old car one
into the boat. With just one 10 watt tricolour nav light (the old
fluorescent type that gave loads of light for low wattage but rotten
colour cutoff) and a similar wattage single cabin fluorescent, plus
oil cabin and anchor lights, a charged old battery usually lasted a
couple of weeks summer cruising. Nights are short, and you don't put
the nav light on till it's genuinely fairly dark. If there's was
nothing around, I admit I turned it off.

>So now the question is this: could I simply move my car's battery to
>the boat? Let's say for a four days cruise during summer time. Will it
>still start the car afterwards? I guess there will be the pleasant
>side-effect that the car will be less likely to be stolen.

Can you push-start your car?
John Wilson
jwilsonNO*SPAM@yachtsnet.co.uk
Remove characters from e-mail address to reply
www.yachtsnet.co.uk - full service online yacht
brokerage with full details and multiple photos
of all boats. Free classified adverts for small
boats and genuinely useful marine links.


23 Jun 2004 06:49:43
Jens K
Re: Using car battery in boat for limited time (was:How much power is in a 100ah battery)

> >
> In the same situation many years ago (very impoverished) I bought a
> newer secondhand battery for my ancient car and put the old car one
> into the boat. With just one 10 watt tricolour nav light (the old
> fluorescent type that gave loads of light for low wattage but rotten
> colour cutoff) and a similar wattage single cabin fluorescent, plus
> oil cabin and anchor lights, a charged old battery usually lasted a
> couple of weeks summer cruising. Nights are short, and you don't put
> the nav light on till it's genuinely fairly dark. If there's was
> nothing around, I admit I turned it off.
> >
> Can you push-start your car?

Well, I don't think I could push-start it, but rolling down a slope
would work. Unfortunately there is no slope at the marina.
However, I think I won't risk it. Coming back from a cruise and not
being able to start the car will certainly make my wife mad, so I
would have to buy a new battery for this reason anyway.
I guess I just dislike the idea of the thing sitting in the boat doing
nothing, almost the whole year, but needing recharging and
attention...


24 Jun 2004 00:03:04
Andy Champ
Re: Using car battery in boat for limited time

John Wilson wrote:
> Can you push-start your car?

Probably not, if it's a modern one with computerised engine management.

Andy



24 Jun 2004 02:41:11
Me
Re: Using car battery in boat for limited time (was:How much power is in a 100ah battery)

In article <d5988190.0406230549.3101e03b@posting.google.com >,
jenku@yahoo.com (Jens K) wrote:

> > >
> > In the same situation many years ago (very impoverished) I bought a
> > newer secondhand battery for my ancient car and put the old car one
> > into the boat. With just one 10 watt tricolour nav light (the old
> > fluorescent type that gave loads of light for low wattage but rotten
> > colour cutoff) and a similar wattage single cabin fluorescent, plus
> > oil cabin and anchor lights, a charged old battery usually lasted a
> > couple of weeks summer cruising. Nights are short, and you don't put
> > the nav light on till it's genuinely fairly dark. If there's was
> > nothing around, I admit I turned it off.
> > >
> > Can you push-start your car?
>
> Well, I don't think I could push-start it, but rolling down a slope
> would work. Unfortunately there is no slope at the marina.
> However, I think I won't risk it. Coming back from a cruise and not
> being able to start the car will certainly make my wife mad, so I
> would have to buy a new battery for this reason anyway.
> I guess I just dislike the idea of the thing sitting in the boat doing
> nothing, almost the whole year, but needing recharging and
> attention...

Sure there is a slope at most marina's. It is called the Launching Ramp.
You just have to be really quick on the clutch, and breaks, and if you
don't get a start, you and your car take a swim........


me


23 Jun 2004 19:19:09
the q
Re: Using car battery in boat for limited time (was:How much power is in a 100ah battery)


"Jens K" <jenku@yahoo.com > wrote in message
news:d5988190.0406220348.488d14d8@posting.google.com...
> > As a very basic answer, a 100 amp/hour battery should provide 100 amps
for
> > an hour or 1 amp for 100 hours, in reality of course it would probably
> > melt if required to do the former. Then you need to factor in age, type
of
> > use, deep charge trickle or whatever. At best it is a guide only as to
the
> > possible maximum the battery can provide.
>
> As I normally daysail I do not need a battery in my boat. But when I
> occasionally cruise for a few days, I would like one, but only for the
> lights. I do not have other power consuming devices in my boat.
>
> So now the question is this: could I simply move my car's battery to
> the boat? Let's say for a four days cruise during summer time. Will it
> still start the car afterwards? I guess there will be the pleasant
> side-effect that the car will be less likely to be stolen.

I used to use a relay in the boot which would charge a second car battery
when the first was full. This I used successfully for several years
occationally i'd swap the (fully charged) batteries over.

The Q
>





25 Jun 2004 00:45:23
Woody
Re: How much power is in a 100ah battery

In article <iILBc.2447$Ag4.21565619@news-text.cableinet.net >, taz24taz24
@blueyonder.co.uk says...
> > They tend to be "high temperature" versions (gets warm in emergency
> > lighting luminaires) so separator design has to be good. Dendritic
> > crystal growth through separators is the usual failure mode of Nicd's
> >
> >
> > --
> > Keith Lewis
>
> Is that a white powdery substance. Or I'm I just
> thinking of corrosion that forms on the aluminium
> casing sometimes.
> taz.
>

FWIW, The white powder associated with (leaking/venting) NiCds is
usually potassium hydroxide, a rather caustic material. A chemical
"cousin" is soduim hydroxide (lye). Don't ingest or get in eyes,
needless to say...

Woody


25 Jun 2004 06:43:23
taz
Re: How much power is in a 100ah battery

>
> > Is that a white powdery substance. Or I'm I just
> > thinking of corrosion that forms on the aluminium
> > casing sometimes.
> > taz.
> >
>
> FWIW, The white powder associated with (leaking/venting) NiCds is
> usually potassium hydroxide, a rather caustic material. A chemical
> "cousin" is soduim hydroxide (lye). Don't ingest or get in eyes,
> needless to say...
>
> Woody

It did tend to sting the skin if it came into contact with it.
taz.




25 Jun 2004 11:22:45
Larry W4CSC
Re: Using car battery in boat for limited time (was:How much power is in a 100ah battery)

jenku@yahoo.com (Jens K) wrote in
news:d5988190.0406230549.3101e03b@posting.google.com:

>
> Well, I don't think I could push-start it, but rolling down a slope
> would work. Unfortunately there is no slope at the marina.

The boat ramp is "sloped"......(c;



25 Jun 2004 22:59:37
Andy Champ
Re: How much power is in a 100ah battery


Woody wrote:
>
>
> FWIW, The white powder associated with (leaking/venting) NiCds is
> usually potassium hydroxide

That's actually a bit of a relief. I assumed it had a lot of cadmium in
it, and I'd rather a hydroxide burn than cadmium poisoning!

Andy.



26 Jun 2004 22:21:18
TB
Re: Using car battery in boat for limited time (was:How much power is in a 100ah battery)

> >
I use an 80 a/h leisure battery ( £35- 40) with a £15 solar charger which
just about stops the natural discharge of the battery. It then requires
charging only about twice a year when the voltage falls to below 12v.

TonyB

> > As I normally daysail I do not need a battery in my boat. But when I
> > occasionally cruise for a few days, I would like one, but only for the
> > lights. I do not have other power consuming devices in my boat.





27 Jun 2004 09:14:01
Norm Taylor
Re: Using car battery in boat for limited time (was:How much power is in a 100ah battery)

I have a friend that uses a car battery in his sailboat. He has no serious
problems. When the battery fails, he just removes it and takes it back for
warranty replacement. Because its not a deep cycle battery it actually has a
decent warranty. The shop does not know its in a boat, but think its in his
car.

Norm

"Jens K" <jenku@yahoo.com > wrote in message
news:d5988190.0406220348.488d14d8@posting.google.com...
> > As a very basic answer, a 100 amp/hour battery should provide 100 amps
for
> > an hour or 1 amp for 100 hours, in reality of course it would probably
> > melt if required to do the former. Then you need to factor in age, type
of
> > use, deep charge trickle or whatever. At best it is a guide only as to
the
> > possible maximum the battery can provide.
>
> As I normally daysail I do not need a battery in my boat. But when I
> occasionally cruise for a few days, I would like one, but only for the
> lights. I do not have other power consuming devices in my boat.
>
> So now the question is this: could I simply move my car's battery to
> the boat? Let's say for a four days cruise during summer time. Will it
> still start the car afterwards? I guess there will be the pleasant
> side-effect that the car will be less likely to be stolen.




27 Jun 2004 20:29:19
John Wilson
Re: Using car battery in boat for limited time (was:How much power is in a 100ah battery)

On Sun, 27 Jun 2004 09:14:01 -0300, "Norm Taylor"
<stormin@eastlink.ca > wrote:

>I have a friend that uses a car battery in his sailboat. He has no serious
>problems. When the battery fails, he just removes it and takes it back for
>warranty replacement. Because its not a deep cycle battery it actually has a
>decent warranty. The shop does not know its in a boat, but think its in his
>car.
Like it



>
>Norm
>
>"Jens K" <jenku@yahoo.com> wrote in message
>news:d5988190.0406220348.488d14d8@posting.google.com...
>> > As a very basic answer, a 100 amp/hour battery should provide 100 amps
>for
>> > an hour or 1 amp for 100 hours, in reality of course it would probably
>> > melt if required to do the former. Then you need to factor in age, type
>of
>> > use, deep charge trickle or whatever. At best it is a guide only as to
>the
>> > possible maximum the battery can provide.
>>
>> As I normally daysail I do not need a battery in my boat. But when I
>> occasionally cruise for a few days, I would like one, but only for the
>> lights. I do not have other power consuming devices in my boat.
>>
>> So now the question is this: could I simply move my car's battery to
>> the boat? Let's say for a four days cruise during summer time. Will it
>> still start the car afterwards? I guess there will be the pleasant
>> side-effect that the car will be less likely to be stolen.
>
>

John Wilson
jwilsonNO*SPAM@yachtsnet.co.uk
Remove characters from e-mail address to reply
www.yachtsnet.co.uk - full service online yacht
brokerage with full details and multiple photos
of all boats. Free classified adverts for small
boats and genuinely useful marine links.


28 Jun 2004 07:56:03
Peter W. Meek
Re: Using car battery in boat for limited time (was:How much power is in a 100ah battery)

On Sun, 27 Jun 2004 20:29:19 +0000 (UTC),
jwilson@no-spam-please-yachtsnet.co.uk (John Wilson) wrote:

>On Sun, 27 Jun 2004 09:14:01 -0300, "Norm Taylor"
><stormin@eastlink.ca> wrote:
>
>>I have a friend that uses a car battery in his sailboat. He has no serious
>>problems. When the battery fails, he just removes it and takes it back for
>>warranty replacement. Because its not a deep cycle battery it actually has a
>>decent warranty. The shop does not know its in a boat, but think its in his
>>car.
>
>Like it

I don't like it much. It means I have to pay
more for every car battery I have to buy.