AKTTKA 9V USB-C Rechargeable Batteries(4Pack), 1000mAh Lithium Batteries with 800+ Charge Cycles & 5-Layer Protection, Compatible Smoke Detectors, Microphones, Toys, Medical Devices

【3700mWh High Capacity】With 3700mWh premium lithium capacity, these 9V batteries deliver significantly more power than typical NiMH 9V batteries and outlast standard disposable alkaline 9V batteries. Unlike NiMH cells with limited capacity or disposable alkaline batteries that fade quickly under load, our lithium batteries provide reliable, long-lasting performance for high-consumption devices like smoke detectors, multimeters, wireless microphones, and other precision electronics that demand consistent power. 【USB-C Direct Charging & 3H Fast Charge】No bulky external charger needed! Each battery charges via built-in USB-C port in just 3 hours. The included 2-in-1 cable lets you charge both batteries simultaneously from any USB port—wall adapter, laptop, power bank, or car charger. 【800+ Recharge Cycles & Low Self-Discharge】Built to last with 800+ charge cycles, replacing hundreds of disposable 9V batteries. Low self-discharge technology retains charge during storage. Always ready when you need them—perfect for emergency devices like smoke alarms and CO detectors. 【Ensured Safety with 5-Layer Protection】Each battery features overcharge, over-discharge, over-current, over-voltage, short-circuit, and temperature protection to ensure safety in every use. Rigorously tested for safe operation in critical safety devices. No memory effect—charge anytime without full discharge. For safe shipping, batteries arrive with low charge. To achieve the best performance and experience, please fully charge and complete 3-5 charge-discharge cycles before first use. 【Wide Compatibility & What's Included】Standard 6F22 size fits 99% of 9V devices: smoke detectors, portable multimeters, cable testers, metal detectors, walkie-talkies, wireless microphones, and more. Package: 4× 9V Rechargeable Batteries, 1× 2-in-1 USB-C Cable, 1× User Manual.