The 'best' ones currently do, which is the challenge. To wit; LiFePO4 (I don't know how to do subscript on HN, sorry) chemistries aren't exotic, and tend to be

The 'best' ones currently do, which is the challenge. To wit; LiFePO4 (I don't know how to do subscript on HN, sorry) chemistries aren't exotic, and tend to be more 'stable'. But, you lose about 14% capacity per volume. [0] [0] - https://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery#Safety https://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery...