Replace All Your AA and AAA Batteries With Eneloops and Never Throw Out Another Battery Again

Oh, ho ho, what’s an Eneloop? I suppose it’s a portmanteau of energy and loop. I’ve never really stopped to think about it. After growing tired of the number of batteries I was using and throwing out, I gave the trusty one-time-use Duracell alkalines I’d (mostly) been using since childhood the boot and went shopping for rechargeables.

That was four years ago. After I installed four rechargeable NiMH Eneloop AAs in the base station of my SimpliSafe home security system and four more in the system’s keypad, I began replacing AA and AAA batteries in everything of mine that ran on them.

Flashlights, voice recorders, and Roku remotes. I stuck them in everything. I haven’t had to throw any out since then or buy any more. And I imagine I’ve saved quite a nice chunk of change on what I’d otherwise have been spending on disposable batteries since that time.

a perfect fit

Eneloops are designed to replace the standard alkaline batteries, so there’s nothing special you have to do to pop Eneloop AAs or AAAs in place of the regular, old Energizers or Duracells you’ve already got in your devices.

You can charge either four AA or four AAA batteries in the charger that comes with some packages of Eneloop batteries. The AAAs charge especially quickly, and a three-color charging light on the front of the charger indicates whether they’re totally depleted (red), partially charged (yellow), or fully charged and ready to use (green).

Panasonic initially stated that the AA and AAA Eneloops could withstand up to 2,100 charging cycles. However, as they point out on an FAQ, that number has been revised downward to 600 charging cycles, as “the IEC standard was revised in 2017 to more stringent test conditions that better reflect real-world usage.” The product packaging still says 2,100 charging cycles, though.

The actual, real-world performance and physical composition of the batteries don’t seem to have changed, based on Panasonic’s wording. Any aging that mine have undergone since I bought them in 2021 and 2022 has been unnoticeable. I’m sure it’s there. It’s just not been enough for me to tell.

As with any battery, from your phone to the electric cars buzzing around the streets, they’ll age with use, as discharge capacity gradually decreases over time due to repeated use and recharge.