Adding an additional FlowZone 18V / 2.6Ah Lithium-Ion Battery (FZAAEN) to your arsenal is the perfect way to maximize potential for your 4-Gallon 18V High-Pressure Multi-Use Lithium-Ion Backpack Sprayer. These rechargeable lithium-ion battery for FlowZone® sprayers are durable battery pack is rated for up to 750 charge cycles. Spray continuously for over 2.5 hours with 3X protection battery technology so that you never have to worry about overheating or overcharging. Never be surprised by a dead battery thanks to the LED indicator lights on the front of the battery. Pressing on the battery icon will show the charge left on your battery and the lights will blink as the battery is charging.