EGO POWER+ 7.5 Ah ARC Lithium(TM) battery features a redesigned fuel gauge. The innovative built-in indicator lights lets you see how much run time you have left in your battery. With 5 segments wrapping the power button, you can now see how much battery power you have left in 20% increments. The unique arc design and patented Keep Cool Cell Technology; which keeps the cells cool, prolonging battery life and making it a perfect power source in the most extreme conditions. ARC Lithium(TM) battery is compatible with all EGO POWER+ power equipment and chargers. It fully charges in under 60 minutes with EGO POWER+ rapid charger, or in 145 minutes with a standard charger. Enjoy a long-lasting power, rapid charging and superior durability no matter the weather and your power needs.