Duane Attaway wrote:
On Thu, 16 Dec 2004, Jonathan Hutchins wrote:
Miatas and some other cares now use a battery that has a sponge-like fiberglass fill that gives some of the advantages of a gell cell while not having the problem of the gell shrinking away from the plates.
Hopefully, lithium and nickel hydroxide batteries will overtake lead acid. Lead is so cheap to make batteries with, so it might be a while. Lead acid batteries go for about $1/pound.
If you're looking for a "beefy" sealed replacement for the gel cells common to most UPSs, and don't want to risk acid spills all over your floor, take a look at absorbed glass mat lead-acid batteries (which is what I think is being referred to above).
These have been sold for years as military batteries, made by folks such as Hawker Energy (http://www.hepi.com/). These are also big on the combat robot circuit, where you have to have sealed, spill-proof batteries for when your 'bot gets chewed up by the opponent (or the floor saws, etc.). The 'Odyssey' line is pretty cost effective and used by many 'bot-heads, but those with bug bucks will sometimes use parts from the military line (ie: BioHazzard http://www.robotbooks.com/biohazard.htm).
You're beginning to see glass-mat technology in high-end automotive batteries (sometimes called "spiral cell", since the glass-mat electrolyte and the electrodes are frequently rolled together the same way as an electrolytic capacitor). Look for "fully sealed" and "absorbed glass mat" in the battery specs to make sure you're buying more than some fancy marketing hype.