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John Wilson
 
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Default 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, (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

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