Accupower 9V NiMH 300 mAh standard battery

Accupower 9V NiMH 300 mAh rechargeable battery

This 9 Volt NiMH cell delivers 300 mAh capacity at 8.4 Volt nominal voltage. It suits devices that accept standard 9 Volt batteries such as smoke detectors, wireless microphones and portable instruments. The chemistry eliminates memory effect so partial recharges do not reduce usable capacity. It is not for users who need the higher voltage of primary alkaline cells or the greater capacity of lithium 9V alternatives.

Simple drop-in replacement with standard charger

The battery fits any compartment designed for a 9 Volt block and charges in common NiMH chargers without special firmware or adapters. No memory effect means you can top it up at any state of charge without capacity penalty. The main issue is forgetting to recharge before the voltage drops below the device cut-off, which can appear as sudden power loss in critical safety gear.

Practical limits of 9V NiMH chemistry

Nominal 8.4 Volt is lower than the 9.6 Volt of a fresh alkaline cell so some equipment may report low battery earlier. The 300 mAh rating limits runtime in high-drain applications compared to primary lithium 9V options. Recharge cycle life is rated up to 1000 cycles; beyond that internal resistance rises and capacity fades. Extreme cold reduces available capacity temporarily.