6.4V 4.5Ah Rechargeable Lithium Iron Phosphate LiFePO4 Battery

This battery is awesome it does not weigh as much as a lead acid battery. If you are building a drone or simply making a small project where light weight is an advantage buy this. I also use it sometimes for solar projects. I charged it with the same DC charger I used for my 6 V lead acid battery. Also charged it with a solar panel works just the same and I don't have to worry about flooding the battery or that sort of thing.