Can car batteries work upside-down?

A-hrs

ous

Recharging issues might come into play with the battery in an other than upright position. I would check with some of the major manufacturers of Lead-Acid paste type batteries. Yausa, Panasonic, Exide, Eagle-Pichard, etc... In other words, a Google search. Unless we have a battery engineer here?

Good luck.

-mpm

I know for a fact that not all car batteries without visible fill holes are really sealed, and I wouldn't be surprised if none are. Even if they're "sealed" that usually means "sealed until it vents" (i.e. they have pressure relief valves), and the valve is going to be oriented down at some point in its life.

I'd check the usual suppliers of _real_ sealed lead-acid cells and see if you can come up with a battery (or parallel combination thereof) that gets you sufficient capacity.

I assume that your application is too cost-conscious to use Li-Po or NiMH?

Dave Vanden Bout wrote: > Are there other types of rechargeable batteries I should consider that

Aircraft batteries might, although they will be expensive.

"Dave Vanden Bout"

Just put the car battery in a spinning centrifuge - so it always has it own positive gravity.

..... Phil

Nice idea, came up with similar :-) Now propose how you'd make the necessary heavy duty connections to it :-p

Pretty sure the gel-cell types can work in any orientation - Yuasa, Sonnenschein(sp?) etc. At least they have data sheets that will specify any orientation restrictions. They are available in similar sizes to car batteries.

Thanks for that information.

Not really. I'm just trying to get the simplest system. A car battery is a single unit, they can easily buy several, and they can easily get a charger to recharge one while the other is powering their system for the day.

I'm not averse to using Li-Po or NiMH batteries except that I don't want to build some custom enclosure to combine multiple cells to get the desired capacity, and I don't want to build some custom charger for it. Maybe these things are already commercially available, but I haven't looked.

Others have mentioned lead-paste cells and aircraft batteries. Those are worth a look as well if a car battery won't work.

Thanks to all who have replied. More replies are welcome!

Car batteries don't like repeated deep discharge. For that, you need an RV/electric outboard battery. Dunno how sealed those are.

Cheers,

Phil Hobbs

Mounts in "almost any position".

G.

Most car batteries are less than 80 amp hours.

greg

According to the Ultimate Authority on Everything, gel cell batteries cannot be charged inverted.

It might be worthwhile actually contacting am actual manufacturer to verify this. But don't get your hopes up if you need to charge while inverted.

You want an absorbed glass mat (AGM) battery. I'm pretty sure they make AGM car batteries, but unless you need a couple hundred amps you're probably better off with a big AGM deep-cycle lead-acid battery.

Use a Gelled-electrolyte or AGM battery rather than one with liquid electrolyte (even if it claims to be sealed). The Gel and AGM batteries are basically lead-acid technology, but have no fluid sloshing around.

How about an airplane battery?

Good Luck! Rich

Really? The two or three websites I looked at all listed capacities over 200 A-hrs. I'll have to look at some of the battery recommendations I've received and get actual capacities. Thanks for the data point.

Thanks to everyone who has replied (even the centrifuge guys)! I now have some contacts for different types of batteries that might meet my needs.

Look at Optima batteries. They work in any position. Several other companies make batteries that are similar.

It's not a good idea to turn an ordinary car battery upside down. Over time, particles tend to flake off from the plates and collect in the bottom. Turning the battery upside down could result in the crud shorting some cells.

Leon

Slip/Collector Rings?