Sanyo's Eneloop Rechargeable was the first of the new generation of low self-discharge (LSD) batteries. It's sold pre-charged, and it retains its charge well in storage. It also lasts a long time in use, even in power-hungry devices such as cameras, and Sanyo says it can be recharged up to 1,500 times. It comes only in AA and AAA sizes, however, so it's not suitable for all uses.
Great for a variety of uses. Although it has only 1,900 mAh of electrical capacity, reviewers say the Sanyo Eneloop Rechargeable has no trouble powering high-drain devices. In a comparison test by Darren Murph of Engadget.com, the Eneloop was able to operate a flash camera through 350 consecutive shots. Brian Nadel of TomsGuide.com reports they also last a very long time in low-drain devices, including a flashlight, CD player and wireless keyboard. Reviewers also say this LSD battery holds its charge very well in storage. Once its charge runs out, however, the Eneloop may take a while to power back up; reviewers who tested the charger sold with the batteries found that it took up to seven hours to recharge a pair of Eneloops fully.
Keeps on ticking. Sanyo claims its newest-generation Eneloop can be recharged up to 1,500 times. So far, no one has ever put this claim to the test; as energy expert Michael Bluejay points out in his battery guide, "it would take years and years for most users to get to even 1000 cycles." However, one professional test found Sanyo Eneloop Rechargeable batteries were still in good shape after 200 cycles of recharging and discharging. In addition, reviewer Stefan Vorkoetter says the first-generation Eneloop batteries in his camera were "still going strong" after five years and thousands of photos.
Choice compares 15 different rechargeable batteries, including the Sanyo Eneloop, by putting them through 200 cycles of charging and discharging and then measuring how much of their original charge they could still hold. Choice also tests each battery to see how well it holds its charge in storage.
Review: Rechargeable AA Battery Reviews, Denis Gallagher, Nov. 21, 2012
2. Michael Bluejay's Battery Guide
Energy expert Michael Bluejay recommends LSD rechargeable batteries for most uses. He names the Sanyo Eneloop as one of the best choices available. He says it's not as high in capacity as his favorite pick, the Powerex Imedion, but the AA size is a better fit in some devices.
Review: Your Guide to Types of Household Batteries (AAA, AA, C, D, and 9V sizes), Michael Bluejay, Not Dated
Vorkoetter tests 13 brands of LSD rechargeable batteries to see how well they hold their charge in storage. The Sanyo Eneloop is an average performer, holding 90 percent of its charge after seven weeks. Vorkoetter also says the Eneloop batteries he has been using since 2007 are "still going strong."
Review: Review: Pre-Charged (Low Self-Discharge) Rechargeable Battery Comparison, Stefan Vorkoetter, Jan. 10, 2012
Brian Nadel tests four different rechargeable batteries, using them on a flashlight and a CD player and also measuring charging times. The Sanyo Eneloop Rechargeable comes out on top, beating batteries from Energizer, PowerGenix and Rayovac.
Review: Rechargeable Batteries Test, Brian Nadel, March 22, 2010
Darren Murph pits three rechargeable battery brands against each other in a variety of high-drain and low-drain devices. He finds all three batteries perform more or less identically and are pretty close in price, but the Sanyo Eneloop has the edge in longevity.
Review: AA Rechargeable Battery Shootout: Energizer, PowerGenix and Sanyo Eneloop, Darren Murph, May 12, 2010
There are more than 5,000 reviews for Sanyo Eneloop batteries at Amazon.com, covering both the original Eneloop Rechargeable and the higher-capacity Eneloop XX. Users say the basic Eneloop has a very low self-discharge rate, works well in high-drain devices and can be recharged hundreds of times.
Review: Eneloop AA with 4 Position Charger, 1800 cycle, Ni-MH Pre-Charged Rechargeable Batteries, 4 Pack (Discontinued by Manufacturer), Contributors to Amazon.com, As of May 2014