Epson P-5000
Lithium–Ion battery
Lithium–ion batteries are renowned for being lighter yet having higher power density than Nickel–based batteries. With Lithium–Ion batteries used in the P-5000, you get longer battery life in a lighter package. There's also the very real benefit of being able to recharge Lithium–Ion batteries when it suits you, rather than having to go through the full charge and discharge cycle typical of Nickel–based batteries.