Eneloop

Eneloop (Japanese: エネループ, Hepburn: Enerūpu), stylized as eneloop, is a brand of 1.2-volt low self-discharge nickel–metal hydride (NiMH) rechargeable batteries and accessories developed by Sanyo and introduced in 2005. Panasonic acquired a majority stake in Sanyo in 2009, and Eneloop batteries were thereafter branded, but not manufactured, by Panasonic.

Eneloop cells lose their charge much more slowly than the 0.5–4% per day loss of previously available NiMH batteries, retaining about 85% of their charge for a year after charging; that allows them to be sold precharged. Since then many other makes of NiMH batteries are supplied precharged, with long charge retention.

Since Sanyo introduced the Eneloop, many other brands of low-self-discharge batteries became available, described as "low self-discharge", "LSD" or "pre-charged". By 2020 most NiMH batteries available were of this type, with varying capacity, self-discharge rate, and lifespan. Those made in Japan are all made in the same factory, but not necessarily to the same specification as the Eneloop brand. There are also counterfeits of Eneloop and other well-regarded brands.

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