Jon Alper's probably insufficiently humble opinion

About eighteen months ago I discovered Sanyo Eneloop rechargable batteries. I own more than thirty of them and they have been amazingly useful. A lot of my devices require AA batteries and I actually deliberately look for an AA option when selecting cameras in particular because they are so readily and ubiquitously available. The problem, until now, is keeping a stock of spare rechargeables has been a royal pain in the neck because they discharge, remarkably rapidly, even when not in use. A battery that’s not ready and charged is useless. Even though I favored rechargeables, I would always keep a supply of disposables on hand for use when my rechargables had simply oozed out their strength in a drawer.

Eneloops stay charged and ready. That oozing away of power in storage is called “self discharge” and most documentation says you’ll lose at least 50% of the charge within a year of storage. In practice, this is actually worse. Eneloops are “low self discharge” batteries and they ship charged, and store charged retaining 80% of their last charge even after sitting for two years. Basically, you can treat Eneloops like disposable alkalines and you don’t generate as much toxic waste, you don’t spend piles of cash you only toss away and, in some scenarios, you’ll get significantly better performance.

A rechargeable that doesn’t self discharge in your TV remote is a good thing. A spare set of AA’s in your camera bag when your flash eats your batteries is a good thing. Batteries in your hand held GPS that work better in the cold is a good thing.

A four pack of Duracell AA’s is 2 bucks. A four pack of Eneloops at Amazon is less than eleven bucks. After the first six charges? The Eneloops are saving you money and they’ll keep saving you money another 994 times.

All that’s reason enough to love them but here are a few more things I’ve noticed using these batteries:

• They function much better in the cold than other rechargables and even alkalines.
• They run cooler. Your gear will be happier, and, in the case of the Nikon SB-900, it will mean your flash doesn’t shut itself off to prevent overheating nearly as quickly. In the case of flashes without that protection, you won’t as easily cook your flash.
• Devices you need available primarily on a standby basis like flashlights, hand held GPS, the extra flash, the pocket camera you keep in your bag, can now be powered with rechargeables with less concern you’d find the batteries dead when you need them.

One thing you will read is that Eneloop batteries have a slightly lower maximum capacity (mAh rated at 2000 for Eneloops) than some other rechargeable batteries. While true, in practice, Eneloops seem to deliver a more consistent voltage and, to be frank, some of the niche super high capacity batteries you’ll find online, don’t live up to their claimed capacity. Having used a half dozen other brands of battery, even without the low self discharge, Eneloops simply perform better. After storage, any actual difference in maximum capacity becomes irrelevant because other batteries will self discharge.

Finally, there’s how durable the actual cells are. One often ignored factor with some of the bargain rechargeables you’ll find is inconsistency in size and durability of the outer insulating covering. At best they may rattle or be a tight fit. At worst, the outer covering can peal off and can cause short circuits.

Below are some links for more info and an Amazon link get your first Eneloops and a charger. When you buy anything at Amazon following the link below, Amazon kicks me back a little money and you don’t spend a dime extra. Everybody wins.

Eneloop Review for general electronics applications: With Analysis