Why I Love Rechargeable Batteries

By Evan Ackerman

[Every now and then our man Evan gets chatty and cranks out a feature length piece. They make for a good read, and this is one of them. We hear they’ll show up now and then. -Ed.]

Batteries suck. We know they suck. They’re a necessary evil at this stage of our technological development. They’re bulky, they’re toxic, they never hold as much as you want them to, and (like all of us) as soon as they’re born, they start the weary and inevitable decline into uselessness. If you’ve ever owned an iPod (or pretty much any other device with a built-in battery) you know what I’m talking about. My iPod is down to about 2 reliable hours, my laptop gets 30 seconds out of a full charge if I’m lucky. As someone who travels a lot, I find it difficult to depend on the lifetime of internal batteries, especially when it comes to power hungry devices. That’s why I love the flexibility and interchangeability of “conventional” batteries, especially rechargeables. I can take my four rechargeable AAs and stick them in my TuneJuice to give me music from LAX all the way across the pacific (a 13 hour endeavour), and then swap the same batteries into my digital camera and take about a bazillion shots (after a quick recharge, of course). I know, integrated rechargeable batteries are sooooo much sexier, but at SOME point you have to put a premium on usability. It’s based on this philosophy of convenience and usefulness. After the jump, I am going to explain why I am such a big fan of interchangeable rechargeable batteries, and why you (and all your gadgets) should be too.

Part 1. The Batteries

Since we’re talking about rechargeable batteries, let’s start with arguably the most important component of the system: the batteries themselves. On the outside, a rechargeable looks like any other standard battery, but on the inside, it’s a completely different animal. There are a bevy of different types of rechargeables, but three are the most common: lithium, NiCad, and NiMH.

You’ll find rechargeable lithium batteries in most things with integrated batteries, like laptops and cell phones, since lithiums have a high power density and a flexible design. Their downside is mainly expense and durability… All those exploding laptop batteries? Yeah, they were lithium cells. NiCads were the rechargeable battery of choice for years, but they contain cadmium, which is a pretty nasty heavy metal, and due to a comparatively low capacity and shorter recharge life, they’re gradually being replaced by our happy friend, the NiMH. NiMH batteries (no relation to either the National Institute of Mental Health or the hyper-intelligent rats) are comparatively cheap, stable, and Earth friendly, with high capacity and a good lifespan. They’re the standard rechargeable drug of choice.

I personally use Maha Powerex NiMHs, which I bought from Thomas Distributing for 13 bucks (for a 4 pack). An often overlooked fact is that rechargeables have substantially greater capacity than normal AA batteries (excluding prohibitively expensive ones like Energizer E2s). My Powerex rechargeables have 2500 mAh (milliamp-hours) of juice a piece (although they’re packing up to 2900 now), while a standard alkaline AA has under 1000 (more like 700 in a medium drain device like a digital camera). When it comes to electrical batteries, the mAh rating is kinda like the size of a gas tank in a car, and (obviously) bigger is better. That is, if you can fill your tank properly, which brings us along to:

Part 2. The Charger

Yes, it’s true, you’ll have to buy and carry around a battery charger that is most of the time more expensive and bulkier than the charger for any individual device. But, I’m willing to bet that it’s smaller (and far less tangle-prone) than ALL of your chargers put together, and can often charge enough batteries to power multiple devices. And best of all, it only eats up one single outlet, which is a major plus if you find yourself needing to charge something in (say) an airport.

That said, it’s important that you buy the right charger. The charger directly addresses some of the major DISadvantages of rechargeable batteries: battery life, battery wear, and (of course) having to actually charge the batteries themselves. Charging batteries is always a trade off between charging speed and battery wear. The faster the charger dumps electricity into a battery, the more stressed out the battery gets, and it won’t hold quite as much charge next time. Another factor that contributes to battery wear is overcharging, or trying to pump more juice into the battery than the battery can actually hold. Most chargers nowadays are “smart” chargers, which means that they use some sort of feedback from the batteries that they’re charging to determine when to stop. While most rechargeable batteries work in more or less the same way, some smart chargers are substantially smarter than other smart chargers, which can have a big effect on the performance of your batts.

I personally use a Maha MH-C410FS charger, which I bought from Thomas Distributing for $40.

Why I like it:

-Trickle mode to keep batteries topped off after charging completes
-Fast charges in 100 minutes, slow charges and conditions in 5 hours
-Separate charging circuits for each battery (4 total)
-LEDs show status for each battery (yay, LEDs!)
-Doesn’t plug directly into the wall, keeping other outlets accessible

Why I don’t like it as much:

-Only charges AA and AAA batteries (doesn’t charge 9v batteries).
-Doesn’t plug directly into the wall, meaning that you have to carry around a power adapter.
-100 minutes is still a while
-Plastic cover is totally useless

Part 3. The Devices

If you’re going to adopt a rechargeable battery mentality, you have to be consistent with your gadgetry, or it’s not nearly as cost (and space) effective. Ideally you want every device to be able to operate on the same type of batteries, and you want to have the minimum number of batteries to power all the stuff that you might conceivably want to have running at the same time. If you look around a bit, it might surprise you just how many gadgets have optional AA (or AAA or 9v) battery adapters. If the manufacturer doesn’t offer one, odds are very high that someone has put one together and is offering it on eBay for about 5 bucks. Heck, you can even make them yourself if you’re so inclined. Of course, you have to weigh the costs and benefits… If only SOME of your gadgets take standard batteries, you’re still going to have to lug around charging cables for the rest, and either way you’re going to have to carry adapters for everything with an integrated battery.

Conclusion

Obviously, there are pros and cons to rechargeables. They involve a substantial investment of both money (around $60 just for the equipment) and time (you have to remember to keep your batteries charged, and rotate sets through your charger if necessary). But not only do they power many medium and high drain devices for a good deal longer than disposables, they’re more cost effective in the long run and are far cheaper and easier to replace than integrated lithium cells. And they’re environmentally friendly, since you’re not haphazardly dumping your used disposable batteries all over the place. But in fact, that very choice is one of the most important advantages: if you rely on standard format rechargeable batteries, you can always choose to use disposables. Run out of power? Forget to charge something? Forget your charger and batteries completely? No worries, wherever you are, odds are excellent that you can find somewhere to buy batteries.