Found an interesting high-end car battery ( Voltphreaks ). If you can get past the price, it has some nice features like :
* 1/5 or less the weight of a normal battery
* Safety auto-off when battery drains to reserve (switchable feature on/off)
* Overcharge protection
* Extended life, around 2000 recharges
* Lithium Phosphate based instead of lead acid
Oh that price... roughly $900.00
