If you're looking for a more stable battery chemistry without sacrificing (too much) energy density, then you might look into LiFePO4 (lithium iron phosphate) batteries.? It's the kind of chemistry that's used in electric vehicle batteries because you can basically cut them in half while they're discharging and they won't even start smoking.? The nominal voltage per cell (3.2v vs. 3.7v) is lower than lithium ion batteries, but a 4S configuration can act as a drop-in replacement for SLA batteries.? In particular, you might look at cells manufactured by A123, or the batteries made by .?
Cheers,
John VA7JBE
