Eneloop

Panasonic's Eneloops are low self-discharge (LSD) NiMH rechargeable batteries first introduced in 2005 (made by Sanyo, which Panasonic took over). They have a nominal capacity of 2000 mAh in the AA size and 800 mAh in AAA size. They seem to perform better than any other LSD cells (Eneloop Self-Discharge Study Eneloop vs. Rayovac Hybrid Eneloop vs. Imedion). While most LSD cells retain 75-80% of their charge after a year, Eneloops can retain 85%. They are very consistent in their performance, retain their original capacity better after many cycles, and deal well with high drain applications (like a flashlight on "turbo"). Therefore if you ask on the forums what kind of battery to buy, you will be told to buy Eneloops. That said, the other brands also perform well, just not quite as well as Eneloops. If money is an issue, try other brands of LSD cells, which can sometimes be purchased for as little as $1 each on a good sale.

In 2010 second generation Eneloops began showing up promising 1,500 charging cycles vs. 1,000 cycles for the earlier versions. The packaging clearly indicates that the new batteries can be charged 1,500 times and the batteries themselves feature a crown graphic on the label. The product number ends with "A" (e.g. HR-3UTGA).

In November 2011 Sanyo started production of third generation Eneloops promising 1,800 charging cycles. The standard third generation cells have metallic lettering and the product number ends with "B" (e.g. HR-3UTGB). On April 26, 2013 Panasonic started selling 4th Generation Eneloops, which now feature prominent Panasonic branding, in regular, light, and pro versions.

Rebranded Eneloops
Duracell The term "duraloop" (a CPF nickname, not an official name) refers to Duracell precharged cells (currently labeled "StayCharged") that are made in Japan and are white around the positive button just like Eneloops, and in fact are thought to be Eneloops re-badged as Duracells. Other Duracell precharged cells have a black top and are made in China, and are not called "duraloop." Duracell also makes non-LSD NiMH batteries (not marked precharged, usually 2450 or 2650 mAh) which may have a green top.

President's Choice A Canadian store brand for Real Canadian Superstore. Some packages of batteries are made in Japan and have identical specifications to Eneloops. A charger combo featured a charger that was identical to Sanyo chargers and while the Sanyo name was not on the front of the charger, Sanyo does appear on the back. As of 2012, these batteries seem to have been discontinued.

Special Edition Eneloops
In 2010 Sanyo introduced limited edition Eneloop Tones which are standard 1,500 cycle Eneloops that come in an 8-pack of different colors. Green and blue Tones showed up in some charger combos in the US. In 2010 sparkling Tones were advertised to be released in November for Eneloop's 5-year anniversary. In October 2011, "eneloop tones chocolat" were announced in 8 earthtone or chocolate colors. There are two Disney special edition third generation Eneloop packages introduced in January 2012. September 2012 saw the release of two new Tones 8-packs, Uomo and Rouge, with Uomo having gray and purple colors, and Rouge being shades of pink. In October 2012, a third version of the Disney special edition was introduced featuring vintage versions of Disney characters. In November 2013, a tropical assortment of Eneloop tones was released in Europe, with Sanyo branding, with third generation specs.

Other Varieties
The Eneloop brand has diversified into light blue Eneloop Lite cells with less capacity (950 mAh for AA cells and 550 mAh for AAA) and supposedly less cost, designed for use in low-drain devices like remotes. Sanyo claims these lighter weight versions of Eneloops can be recharged 2,000 times. Introduced in June 2010.

In late 2010, Sanyo introduced black Sanyo XX cells using Eneloop technology (higher capacity than Eneloops at 2500 mAh for AA, but not as low self-discharge: more like 75% after a year and said to be good for 500 cycles). These were marketed primarily in Europe. They also appeared in metallic orange wrappers, labelled Harmolattice, marketed in Southeast Asia, but Harmolattice batteries are not precharged. In 2011, Eneloop XX batteries were renamed Eneloop Pro in Japan but keep the black wrapper. In October 2012, the Eneloop Pro was expanded to AAA size with a capacity of 900mAh, available outside of Japan as Sanyo XX or Eneloop XX. In April 2013, Eneloops will be labelled Panasonic.

The Eneloop Plus was introduced at the same time as the Eneloop Pro. The Plus has a thermistor that monitors temperature of the battery and will cut off power in case of a dead short or if batteries are inserted incorrectly.

Many of these Eneloop offshoots are available only in Japan.