What is "eneloop"

is a brand of 1.2 Volt nickel–metal hydride (NiMH) rechargeable batteries and accessories, developed by Sanyo (now Panasonic) and introduced in 2005.

As low self-discharge nickel–metal hydride batteries, Eneloop cells lose their charge relatively slowly—approximately 15% in the first year, compared with the 0.5% to 4% per day lost by older technology NiMH batteries, which are usually not sold precharged and ready for immediate use.

Because they can replace a large number of alkaline batteries over their life cycle, they are marketed as being eco-friendly.

Sanyo was acquired by Panasonic in 2009. As part of that deal, the Japanese Eneloop factories were sold off to Fujitsu, who since then produces 2nd-generation eneloops under its brand. Panasonic eneloops, starting with the 3rd generation, are made in China for some markets (including Australia). As of November 2015, Eneloop Pro remains made in Japan.