Can you use rechargeable batteries instead of alkaline?

A rechargeable NiMH AA or AAA is the same size as an alkaline one, but 1.2 V against 1.5 V. Microsoft recommends them for the Xbox Wireless Controller, while Roku says not to use them in its remotes.

NiMH and alkaline AA side by side

Low drain and high drain devices

Energizer’s NiMH handbook says a NiMH AA gives about 75% of an alkaline AA’s capacity in low drain devices, and can beat alkaline in high drain ones such as digital cameras. A NiMH cell also holds a flat voltage as it runs down, where an alkaline’s slopes.

That flat curve can fool a battery gauge. Kwikset says rechargeables won’t harm its smart locks but aren’t recommended, because the battery percentage the lock shows may not be accurate; it recommends alkaline. August doesn’t recommend rechargeables in its Wi-Fi Smart Lock, “because of their limited capacity”.

Charging and care

• Energizer says to charge them at room temperature, 68 to 72°F.
• Don’t leave them flat or unused for long: Energizer says to charge them at least every 6 to 9 months.
• Never recharge a battery that isn’t marked rechargeable. Energizer and Duracell both warn it could rupture or leak.
• Energizer says its Recharge Universal AA can be charged up to 1000 times, and holds a charge up to 12 months in storage.

Storing them for a long time

Energizer’s NiMH handbook says a NiMH cell left in a device can slowly seep electrolyte around its seal. For long storage it suggests taking it out of the device, or putting insulating tape over the positive end, and storing it charged.