PicDude wrote:
> Now, I have a battery here that claims 58AH.  My google research tells
> me this means 14.5A for 4hrs, at which time the battery voltage will be
> 10.5V.  But that is apparently 10.5V *loaded*.
>
> So what happens if I only consume 2A

In theory you get 58AH / 2A = 27 hours.

> Generally a car battery is
> considered 0% charged when the open-circuit voltage drops to 11.8V.
> And generally considered to need charging (75% charged) when the
> voltage drops below 12.4V. But that's for a car -- and I'm sure there's
> a lot of useable capacity below that.

Probably not.  I don't remember lead-acid battery discharge curves off the
top of my head, but most batteries are far from linear.  Also these
batteries can get damaged if discharged too deeply too often.  Ordinary car
batteries are not rated for "deep discharge".

> If absolutely necessary, I'll drag it
> back to the motel and charge it, but really want to avoid that --
> something about a lead-acid battery in an enclosed room (that I'm
> sleeping in) that does not thrill me.

So charge it in the bathroom and leave the window cracked if you're really
worried about it.  I don't see a problem unless your charger breaks and
overcharges the battery.  That would release hydrogen sulfide fumes.

Anyway, if the show is at this remote site and you get "back to the motel"
every night, you probably have access to a car.  Can you use it to charge
the batteries?


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