The Ego POWER+ 56-Volt 2.5Ah battery uses industry-leading ARC lithium ion technology to deliver long-lasting power, rapid charging and durability in all weather conditions. The keep-cool battery technology keeps each cell cool for long life and work in the most extreme conditions. It features an integrated fuel gauge to let you know how much power is left in your battery. Charges in 30 minutes with rapid charger. Charges in 50 minutes with standard charger. ARC litium ion battery is compatible with all EGO POWER + power equipment and chargers. 3-year warranty.