Eneloop is a brand developed by Sanyo encompassing rechargeable batteries and associated devices, introduced to the market in November 2005. The batteries are low self-discharge NiMH, which lose their charge much more slowly than ordinary NiMH batteries; 10% in the first year, compared to about 4% of their charge per day of storage. Due to the number of alkaline batteries they can replace during their lifecycle, they are marketed as being eco-friendly when used appropriately.