Note:11.1V is Vacuum's battery voltage. NOT charger's voltage. Please Check For Compatibility With Your Unit. Thanks. Note: Rechargeable batteries typically last 1 to 3 years. If a battery is old or depleted,it may not charge,but this isn't necessarily the charger's fault. To determine if the charger is working,use a voltmeter. Compatible with listing item ASIN: B0CR5VFKW6 - 2024 Upgraded Handheld Pool Vacuum with Telescopic Pole,Enhanced Powerful Suction,2 in 1 Cleaning Head,60-Mins Runtime,Cordless Rechargeable Pool Vacuum Cleaner for Small Pools/Spas/Hot Tubs saschedross AC Adapter Replacement For Winny 100P HJ30 11.1V 2600mAh Li-ion Battery 30W Rechargeable Handheldless Robotic Pool Vacuum Floor Cleaner 1A Power Supply Mains PSU