Rechargeable batteries vs non-rechargeable ones

  • Last updated on January 4, 2017
  • Hardware

I have been using rechargeable AA and AAA batteries for a few years throughout my home and thought of doing a writeup on how it has been working for me and why you should consider doing the same.

Why use rechargeable batteries?

If you need reasons and going green is not your cup of tea, here are just a few but very compelling ones.

To avoid having leaky stains

What bothered me most was the leaky stains from alkaline batteries. If you are going to tell me to get better brands, I will tell you I have used various popular brands and have experienced at least one of them leaking.

Just how annoying this problem is to me? Take a look at the permanent stain on my clock.

Clock with alkaline battery leak stain

That is not all. There was a leak on one of my air-conditioner remote controls that permanently damaged it.

Cost

I bought many dozens of Panasonic Eneloop batteries from Japan. Afraid that non-Panasonic chargers might shorten their lifespan, I bought a Panasonic charger as well, model BQ-CC11. It can charge between 1 and 4 batteries at a time including mix of AA and AAA.

Panasonic AA/AAA battery charger BQ-CC11

Without considering the charger (which costs roughly 8 pieces of AA Eneloop), Eneloop is 7-8 times more pricey than branded alkaline batteries. While that seemed steep to some, the maximum number of recharge cycle count must be factored to realise its cost benefit. I bought 4th generation ones that could be charged up to 2100 times. Even if we deeply discount manufacturer claims to say 500 times, the returns is too large to be ignored.

Relatively long rate of energy retention

I have tried 2 brands (will not disclose the names) of non-LSD rechargeables and find their retention period very low; having fully charged and inserted into an old digital camera low battery indicator lit up after just a few days of non-usage. What about low consumption like clocks? After using for slightly over a month, the clock stops.

Modern Low self-discharge (LSD) batteries can retain 75% after 5 years. Good enough for clocks.

Testing the voltage of newly unpacked AAA which I bought over 2 years ago, not yet factoring how long they have been on the shelves, voltage is at a respectable 1.17V:

Battery tester

Can power just about any device that accepts AA/AAA sizes

I am using on the following devices:

  • Wall clock
  • Fan remote controls
  • Air-conditioner remote controls
  • TV remote controls
  • Wireless keyboard and mouse
  • Cordless phone (the only pair of AAA that is not charged using Panasonic charger as it is charged by the phone dock)
  • Electronic weighing scale
  • Electronic door lock
  • Electronic toothbrush

Most devices work as they should except one. Even after fully charging a pair of AA Eneloop, a Bluetooth radio alarm clock complained of low battery. It is connected to the mains so the batteries serve only as backup time keeper in case of grid power outage. Despite whatever the indicator says, it continues to work except that I have no way of telling when the device is truly low in battery.

I am a bit disappointed that the manufacturer (popular brand) did not make this device cater for rechargeable NiMH batteries that have lower nominal voltage at 1.2 compared to regular non-rechargeable ones at 1.5.

A fully charged Eneloop outputs roughly 1.45V as measured by the same battery tester used above.

Important tips

Do not to let your rechargeable batteries overdischarge as this will damage it. Set a reminder in your favourite calendar or to-do app for a periodic topup. The period to topup of course various across devices.