All batteries have a max charge rate, despite the hype. Charge a
small battery at too high a current rate and see it heat up and buckle
the plates, pop the vents and boil the electrolyte out. You can treat
the small AGM like a gel-cell, for the most part.
My Toyota Prius has a 12 volt AGM in it as the aux battery so I did
some research on them last fall. A one amp, 12 volt wall-wart charger
will do the job on yours, if you want to monitor the voltage after a few
hours. It ought to get the battery up to 80% charge in 7 hours,
assuming it was flat to begin with. Not a good idea to get it below 30%
depth of charge (DOD) though. Best charger choice is a "smart" charger
that limits the current and has a "float" function. Float is like
trickle on a NiCD charger. You can leave it connected all the time.
Lots of info on the web.
Cheers,
CR
James Nazarian wrote:
> I know there are some people here that know way more about electricity that
> I do, and I have a few questions for those folks. Feel free to reply off
> list if you wish.
>
> I bought a small 12V 7Ah absorbed glass mat battery the other day and I have
> a couple of questions about it.
>
> 1. The guy that sold it to me said you can't use a standard battery charger
> on it but that I should use a run of the mill 12V 1A wall transformer as a
> charger is that true? Why?
>
> 2. What is to keep it from overcharging or boiling the battery?
>
> 3. If the battery is 7Ah and the charger is 1A will it take 7 hours to
> charge the battery?
>
> Those are the questions that come to mind right now. Thanks.
>
> James Nazarian
> 71 MGBGT V8
> 71 MGB Tourer
> 87 BMW 325es
|