They beat the socks off others in cold weather, too, and energy density is very high (highest?). Great radio batteries - lightweight and powerful. I have not used the standard cells (like AA), though - are they 3 volt instead of 1.5 volt? Seems like I read that somewhere - like, either a dummy cell or a bulb change needed for incandescant lamps. I know the electronics in my LED flashight are not rated for lithium AAs - maybe that's why?