Can car batteries work upside-down?

"Dave Vanden Bout"

BTW 240 Ahr is one huge "car battery ".

..... Phil

I think you're maybe thinking of "Cold Cranking Amps", which has to do with the way the plates are designed. I've never seen an amp-hr rating on an ordinary car battery in the ordinary car battery places, and I've looked! - I guess you're supposed to just know (or follow the car mfg's recommendation). I think I read somewhere once that a typical car battery is about 55 AH. I think in boat places they DO publish the AH rating, but you'd damage a marine battery if you tried to get 200A out of it. =:-O

I know a little about batteries - a few years ago, I worked for an industrial battery charger manufacturer. :-)

Cheers! Rich

I'd go look at the Concorde Aircraft battery site. Aircraft batteries are generally intended for use in any configuration without leaking. The old flooded plate batteries had a little marble in the vent cap that sealed off the vent cap when the aircraft was inverted. The new AGM batteries are pretty well completely sealed.

Jim

-- "It is the mark of an educated mind to be able to entertain a thought without accepting it." --Aristotle

Tested that idea today - it is false. Gel cell batteries (at least the ones I tested) do charge inverted. My guess is that the Wiki statement ought to say they _should_ not be charged inverted as opposed to they _cannot_ be charged inverted.

Ed

There are Lithium Phosphate in an automotive package. They quote capacity (at C/2 yet!) as 100Ah compared to 45.6Ah for lead acid.

They claim "Can be recharged using most standard lead-acid chargers (set for AGM/GEL cells)". I would expect a cost premium though.

Robert

All that and I didn't include a reference

Robert