Rechargeable Batteries that Don’t Lose Their Charge – LSD cells
NiCd rechargeable batteries have been around for decades, preventing tons of toxic battery waste, before the new NiMH (Nickel Metal Hydride) types were designed to cure the old NiCd’s “memory effect”. So far so good but, until recently, no one has ever managed to make a rechargeable battery that kept its charge for prolonged periods. When you take your point-and-shoot camera out of the drawer a few months after fully charging the batteries, it barely has enough charge left for a few pictures. Or your portable DVD player quits on you in the middle of a film.
Now the new low self-discharge (LSD)(don't get too excited, it's a legal substance) batteries from Sanyo (eneloop), Panasonic and other manufacturers finally seem to have this issue under control.
I switched to rechargeable batteries a long time ago, partly because it’s “green”, but also because it was good for my wallet. At first I was happy with the NiMH types because at least they got rid of the memory effect that reduced the batteries’ capacity after a few cycles. But they also have a very annoying weakness in that they don’t keep their charge for very long. You can fully charge them, but even if you don’t use them, they lose about 1% of their charge per day. When you need them unexpectedly after a few months, there’s virtually no charge left.
The new low self-discharge, or LSD, batteries use an improved technology that practically eliminates this self-discharge effect. The best evidence of this is that they come pre-charged and ready to use straight from the box, and even after a few months on the store’s shelves, they still have most of their charge. At last you can simply charge your batteries and use them with confidence the next time you need them. The following table shows the discharge speed of Sanyo eneloop vs regular Sanyo rechargeable batteries.
Just like the standard rechargeable, these batteries can provide a relatively high output current compared to alkaline batteries, making them suitable for power-hungry devices such as digital cameras. On the downside, like other rechargeables, they have a 1.2 volt rating, which is less than the 1.5 V from alkaline batteries. In most cases, though, this won’t be an issue.
- NiMH rechargeable batteries that don’t self-discharge in the drawer
- No memory effect
- Available in AA and AAA sizes
- Approx 90% capacity left after 3 months (depending on type)
- High output current, even more than traditional NiMH
- Use a certified charger, preferably, though most modern NiMH chargers should also work fine; Sanyo recommends at least 2 hours’ charging time for the eneloop
- 1.2 V like other rechargeables
- 2000 mAh for the Sanyo eneloop AA model at time of publishing
- Up to 1000 recharge cycles
- No need for last-minute charging.
LSD batteries are available from Sanyo (called eneloop), Duracell (pre-charged rechargeables), Panasonic (Infinium), Energizer and probably some other brands as well.
You can read a more detailed description on the Sanyo eneloop website and also an independent test report. A great eneloop-based product, that can be used to charge your batteries and, in turn, can charge your smartphone is the eneloop USB booster stick.
Another alternative, if you’re looking for batteries that hold their charge, is to recharge your regular alkaline batteries (yes you can!) using specialized alkaline chargers.
Where to buy
Approx. price: $22 (March 2010, 8-pack Sanyo eneloop AA)
Categories: portable devices, power,green
Other Rechargeable Battery solutions on Clever & Easy