by Paul Mah

Sanyo Eneloop: The Best Rechargeable Batteries for Your Gadgets

May 23, 20123 mins
Computers and Peripherals

Not all rechargeable AA or AAA batteries are created equal. blogger Paul Mah has found what he thinks are the best rechargeable batteries in Sanyo's eneloop products.

Many of the products I review on my Gadget Navigator blog use AA or AAA batteries. Most vendors bundle the required batteries with their devices. But wasting so many batteries has really started to bother me.


Lots of my own personal gadgets such as my trusty Logitech Anywhere Mouse MX or Apple Wireless Keyboard also use batteries, and my heavy use of these devices means that I replace the batteries fairly often. I haven’t kept a specific count, but I estimate that I’ve been using half a dozen or more batteries every month or so.

I recently started exploring the use of rechargeable nickel-metal hydride (NiMH) batteries. NiMH batteries do not suffer “memory effect.” And they looked like an ideal replacement that could generate a return on my investment after just a year or so. Unfortunately, I quickly realized that NiMH batteries suffer from one crucial weakness: They have a very high rate of self-discharge, meaning they discharge when not in use.

Most NiMH batteries can lose more than half of their full charge when kept for a mere two months on the shelf. And the impact is felt more as their capacity reduces with use or if the batteries are stored at higher temperatures, which is unavoidable in certain regions. This is unacceptable for me, so it was back to alkaline batteries…at least until I stumbled upon the eneloop rechargeable batteries.

The eneloop battery was created in Sanyo Japan by Taishi Maeda in April 2005. Sanyo claims the eneloop batteries retain 75% of their charge after three years, compared with traditional NiMH batteries, most of which would be completely dead in far less time. And the lower self-discharge rate makes them ideal for use in low-drain gadgets such as noise-cancelling headphones, wireless presenters, wireless keyboards and wireless mice.

I’ve been using eneloop batteries for more than half a year now, and I always have full-charged batteries ready when my current ones run out of juice. I simply swap new ones in and remember to pop the exhausted ones into the charger. In fact, they’re working so well that I just bought a second pack of eight AA batteries and I’m considering buying the “C”- and “D”-size adapters for use with my daughter’s various battery-powered toys. A pack of eight AA and four AAA batteries with charger is currently available on Amazon for $33.95 (After discount).

Have you used conventional NiMH rechargeable or eneloop batteries? If so, I’d love to hear your experiences.