Yes, 10.5V is what I've calculated too.  But I'm wondering if the AH =20
rating is to that voltage, or to a safer voltage.  If I go to 11V, how =20
much of the 50AH can I get? Is the drain relatively linear from 12.6 =20
to 10.5V, so I can expect about half of the 50AH?

Either way, some of these shows provide electricity, but at this show =20
I want to power some electronics in a different section of the show, =20
where they can get me an extra electrical outlet costs for ~$135.  I =20
can buy a new car battery instead for $70 and dump it (yes turn it in =20
for the core charge) when I'm done.

At this point, I have another bonus:  instead of powering the devices =20
with 12V and letting the linear regulators in each drop that to 5V, I =20
can easily run a 12V-5V buck switcher after the battery and drop by =20
power requirements by about half.  My calcs with this method is now =20
16AH required.

Cheers,
-Neil.



Quoting IVP <joecolquitt@clear.net.nz>:

> In my occassional applications with wet and SLA batteries I use
> a load cut-out set to 11V. I believe below 10.5V (ie 6 plates by
> 1.75V) is the critical V for leaving batteries uncharged for any
> length of time (a few days I think)
>
> It doesn't sound like that voltage is going to be reached in the first
> couple of days in your application so you might just need to do a
> charge immediately after the show
>
> Joe
>
>
>
>
> --
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