Batteries: Recharge & Reuse

MaximalPower FC999

Not for laptops, phones, tablets and all the other gadgets we own with lithium-ion rechargeable batteries embedded in them; we’re talking about all those other things that are powered by AA and AAA batteries (and parents especially will understand what we mean here).

According to an EPA document (archived at Stanford University), about 3 billion dry-cell batteries are purchased each year in the USA. Of those, about 20% are rechargeable, leaving 2.4 billion that are thrown away after a single use. Switching even more of those to rechargeable alternatives would be a great start, but I suspect that quite a few are sold embedded in toys and gadgets, either as the included batteries or intended just for the in-store demonstration modes.

Rechargeable AA & AAA Batteries

If you haven’t already switched to rechargeable versions of these, you should. Look for NiMH cells, and get a charger that can recharge them, for the easiest solution. Our preferred brand for these is Panasonic’s Eneloop, though we’re also OK with Energizer and even Amazon Basics. We have not had good luck with Duracell NiMH cells, however, and would not recommend them (more than half the ones we bought refused to charge after a few cycles).

MaximalPower FC999

We have a number of different chargers, one that came with our first pack of Energizer AA cells, one that came with a pack of Eneloop cells and, our favourite, the MaximalPower FC999 Universal Rapid Charger. This charger is more sophisticated than either of the others, and in particular has modes for recharging NiMH, NiCD and even alkaline cells. It also has an LCD display & LEDs to let you know what it is doing and claims to be controlled by a microprocessor.

Recharging Alkalines

The first thing to say here is that, while the FC999 does recharge alkaline cells, they do not come close to the number of cycles that an Eneloop NiMH cell can handle. I have been using the same 4 Eneloop cells in my wireless keyboard and mouse at work for several years now and they are still going strong; our alkaline cells rarely handle 10 cycles. We do not buy alkaline AA or AAA batteries, but we do still get some of them embedded in things at the factory. We also volunteer to handle battery disposal for our kid’s pre-school.

The FC999 has allowed us to recharge probably 80% of the alkaline cells that have come into the house, allowing them to be used again in toys, clocks, and even our kids’ electric toothbrushes, which came with two Duracell AAA cells. While we are not fans of Duracell’s NiMH cells, their regular “copper top” alkaline cells seem to handle being recharged very well, at least for a few times. Many of the less well known brand batteries we find in toys recharge well too.

The one brand of alkaline cells that we do not like finding is Kirkland (the Costco brand); almost every time we open a toy with them inside we find at least one is leaking, always needing cleaning (vinegar) and sometimes even resulting in damage to the contacts that requires repair. As a result of this, we also do not risk recharging them in case they leak or overheat in the charger.

Solar Path Lights

We have a few of these around the garden, and periodically they will stop working. In many cases, opening them up, popping out the battery and recharging it in a charger will get them back up and running. Oftentimes though these will be NiCD batteries, which is where the FC999 comes in handy again with its NiCD mode.

When the battery refuses to recharge, or no longer lasts very long even after a deep charge, we have swapped ours for SunLabz 1000 mAh NiMH cells (which work even better than the original NiCD cells in our lights).

Note: Remember to clean the solar panel glass while you’re charging/swapping the batteries, and you will get more life from your solar path lights.

Kentli Li-Ion AA Batteries
Lithium Cells

We also have some security cameras that run from a couple of AA cells. In this case though they came with Energizer Lithium cells (not to be confused with Lithium-ion cells). Lithium cells have the advantage of having a longer life, but they are not safe to recharge as far as we can tell. Certainly not in a charger that was not designed for the purpose.

We have recently found some lithium-ion cells in AA form factor, but not yet tried them: Kentli 3000 mAh Li-ion AA cells. They are very expensive, but may well provide a rechargeable option for the security cameras with a similar lifetime.

Button Cells

In most cases, these last long enough that the lack of a rechargeable alternative is less significant, as long as they are sent for recycling when they are exhausted. There is one exception to this that I am still looking for a good solution to: the LR44 button cells used by Hexbugs. For those unfamiliar with Hexbugs, they are essentially an older style phone vibrator + an LR44 button cell in a bug shaped case on silicone legs. Surprisingly, the motion from the vibrator makes them run around in a fairly convincing bug-like way. Our two kids love them.

Unfortunately, that motor is also very good at draining the small button cells quickly, and none of my attempts to recharge them have been very successful; they do work, but for far less time than the new cells. Early attempts at this also resulted in some impressively loud popping sounds as the cell overheated and burst the metal case wide open.

Note: Unless you are very confident that you know what you’re doing, we do not recommend trying to build your own battery chargers, or even trying to recharge batteries using the wrong type of commercial charger. It can be very dangerous.

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