MaximalPower 9 volt li-ion rechargeable battery HIGH CAPACITY, 550mAh has absolutely no memory effect so that you can charge battery at anytime. Integrated microchip prevents overcharging and lengthens battery life! Replaces the following batteries: Almost all 9V Alkaline, Ni-Cd, Ni-Mh & other Li-ion Batteries! NOTE: 1. Please FULLY charge your rechargeable batteries before first use. When in doubt, charge your batteries overnight (8 hours); 2. Please fully cycle your Li-ion batteries (fully charge, then fully discharge them) at least once before regular use; 3. DO NOT full charge your Li-ion batteries before storing them for long periods of time. Discharge them close to half a charge first. is the only authorized dealer selling MaximalPower brand products. Please make sure your item is ONLY sold and shipped by ! All other marketplace vendors are selling counterfeit products that do not perform the same, and/or are not covered by our MaximalPower Warranty. "

Great to use for Smoke Detectors, MicroPulse Medical Device, most children's toys, and anything else that's compatible with 9V. 9V Batteries can be used for smoke detectors, some older transistor radios, handheld test equipment, electronic toys, and more. HIGH Capacity: 9v 600mAh (Will NOT affect battery compatibility). Chemistry: Li-Ion, Output Volts: 3.7V. Replacement battery for 9V alkaline batteries.