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.

In message , taz
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

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.

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.

"Jens K" wrote in message
om...
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

"Jens K" 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.

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

In message , taz
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

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.

On 22 Jun 2004 04:48:35 -0700, (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

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.