Thread looks a bit confusing: Evoforce is selling a used Tesla lead acid 12V battery, not a Battmobile battery (If I'm wrong, I call first dibs on a Battmobile battery!)
I looked up Battmobile: their new name
IS Element3 Batteries. According to their website, their lithium battery saves over 17 pounds from stock lead battery:
- 35% of the weight of OEM battery (increase efficiency, 9.5lbs vs. stock @ 27lbs)