Like the rechargeable LED light bulbs, I was first introduced to the concept of USB rechargeable batteries through a particular brand.  Pale Blue Earth batteries have their own particular benefits — most notably, that they come in a good range of sizes.  You can buy Pale Blue Earth batteries in AAA, AA, C, D, and 9V, which should cover most of the “everyday” batteries in an average household.

ECO Recharge Batteries

The ECO Recharge batteries I bought have the disadvantage of not coming in as wide a range of sizes.  As far as I know, they only come in AA and AA.  But they have a couple advantages of their own.

On the one hand, they’re just fun.  With a visual design resembling little monsters, they say, “Feed me!”

This obviously isn’t necessary; purely functional batteries still function.  But if you have to use batteries anyway, you might just as well have fun-looking batteries as boring ones, right?

The more meaningful characteristic, though, is that the two sizes of battery are different.  Duh, right?  Obviously, all AA batteries are different from all AAA batteries in some respects.  But because the two sizes of batteries are two completely different colors, it’s very easy to tell at a glance which batteries you have, even without being close enough to differentiate them by size.

I hope the company decides to expand into additional sizes — and I hope they continue to make each size its own distinct color.

USB Rechargeable Batteries

A USB-rechargeable battery is probably pretty self-explanatory as a concept.  These batteries charge pretty much directly from a USB port; they don’t have to go inside chargers.

Each battery contains a micro-USB socket — like what many phones and tablets use.  These typically come with small “branched” cords so you can plug a full set of batteries into a single (standard) USB outlet.  I successfully charged mine both from my laptop and from a “freestanding” USB outlet like you might plug a phone into.  (Ours is part of a lamp.)

These particular batteries have small lights that glow red while they’re charging, and blue once they’re fully charged.  (Oddly enough, we found that all four batteries did not finish charging at exactly the same rate.)

The packaging says they charge in 8.5 hours.  I’m not sure ours took that long — although perhaps they arrived not fully dead — but they certainly didn’t take any longer.  They seem to work well in place of standard (non-rechargeable) batteries in my flashlight, but I haven’t had them for long enough to speak to how well they hold a charge or how long their overall life is.

Rechargeable AA Batteries with USB Charger by Pale BlueRechargeable Batteries AA UzoneAA Batteries – USB Rechargeable

I also am not completely sure whether the charging cables are interchangeable.  As far as I can tell, they’re simply USB-to-microUSB cables, so any USB-to-microUSB cable should work — and that would make them interchangeable.  But I don’t have any kind of documentation that indicates that and would make it clear that various brands can be used interchangeably.

If you’re concerned about losing cords, you can even find some brands (see the light blue batteries above-right) that plug directly — as in, directly directly — into a USB port.  The down side of these would be that you can only plug in one at a time, not a full set.  The up side would be not having to keep track of charging cords.  Think about what best meets your needs and shop accordingly.