Yah, lithium's power/weight advantages had driven so much investment that its now has awesome power/volume advantages too. The result is that even things which

Yah, lithium's power/weight advantages had driven so much investment that its now has awesome power/volume advantages too. The result is that even things which don't care about the weight (http://www.storagereview.com/apc_backups_pro_500_lithium_ion_review http://www.storagereview.com/apc_backups_pro_500_lithium_ion...) are starting to switch from lead acid because its no longer the super cheap solution. That is something I've found really curious because if you tear into just about any lead acid battery it still looks like technology from the 1950's. Just about everything else has shrunk, become lighter, used less material, etc. But lead acid's last major "breakthrough" was in the 1970's with gel cells. I would have expected lead acid to look more like a capacitor at this point (thin layers of material rolled/folded up) but its still these fairly thick plates sitting in electrolyte with non-existent charge control. Surely some creative person sitting in a lab could come up with way to minimize sulfation or to decompose the lead sulfate within the battery without basically melting them down and building new ones.