The
low self-discharge nickel-metal hydride battery (
LSD NiMH) was introduced in November 2005.
It reduces
self-dischargeSelf-discharge is a phenomenon in batteries in which internal chemical reactions reduce the stored charge of the battery without any connection between the electrodes. Self-discharge decreases the shelf-life of batteries and causes them to have less charge than expected when actually put to use.How...
and, therefore, lengthens shelf life compared to normal NiMH batteries. By using improved separator and improved positive electrode, manufacturers claim the batteries retain 70 to 85% of their capacity after one year when stored at 20 °C (68 °F), while standard NiMH batteries may lose half their charge in this time period.
The
low self-discharge nickel-metal hydride battery (
LSD NiMH) was introduced in November 2005.
It reduces
self-dischargeSelf-discharge is a phenomenon in batteries in which internal chemical reactions reduce the stored charge of the battery without any connection between the electrodes. Self-discharge decreases the shelf-life of batteries and causes them to have less charge than expected when actually put to use.How...
and, therefore, lengthens shelf life compared to normal NiMH batteries. By using improved separator and improved positive electrode, manufacturers claim the batteries retain 70 to 85% of their capacity after one year when stored at 20 °C (68 °F), while standard NiMH batteries may lose half their charge in this time period. Low self-discharge cells are marketed as "ready-to-use" or "pre-charged" rechargeables.
Low self-discharge NiMH batteries are good for photography and other high energy requirement applications. Due to the low self-discharge, they are also suitable for long-term intermittent or low-current uses; they might last a year or longer between charges, much better than ordinary NiMH batteries. They can therefore also be used for electrical
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s,
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s, etc.
Aside from their longer shelf life, and moderately higher prices, they are otherwise similar to normal NiMH batteries of equivalent capacity and can be charged with normal NiMH chargers. However they are generally available at lower capacities than the highest capacity of normal NiMH batteries.
Brand names for LSD NiMH batteries include AccuEvolution from AccuPower, Hybrid from
RayovacRayovac is a brand of batteries made by Spectrum Brands of Sandy Springs, Georgia, United States. Rayovac was founded in 1906 as the French Battery Co. in Madison, Wisconsin, United States. In 1930 the company name was changed to Ray-O-Vac, and shortly thereafter the company patented the first...
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Sanyois a major electronics company and member of the Fortune 500 whose headquarters is located in Moriguchi, Osaka prefecture, Japan. Sanyo targets the middle of the market and has over 324 offices and plants worldwide, together employing more than 11,000 employees.On November 2, 2008, Sanyo and...
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PanasonicPanasonic is an international brand name for Japanese electric products manufacturer Panasonic Corporation Under this brand the company sells plasma and LCD display panels, DVD recorders and players, Blu-ray Disc players, camcorders, telephones, vacuum cleaners, microwave ovens, shavers,...
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Gold PeakGP may refer to:In business and media:* Gestair's IATA airline designator* Girard-Perregaux, a luxury brand of Swiss watches* Gold Peak, maker of the GP batteries and GP portable solar charger.* Göteborgs-Posten, a daily Swedish newspaper...
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.
Most manufacturers produce only size 'AAA' and 'AA' batteries and the vast majority of low self discharge batteries are sold in these sizes. However, many battery companies also market a
low capacity 'C' and 'D' battery by inserting a AA battery into a larger case. Re-wrapped 'Cs' typically have a capacity of just 2,000 to 2,200 mAh. Re-wrapped 'Ds' typically have a capacity of just 2,000 to 2,200 mAh when constructed of one 'AA', or 4,000 to 4,400 mAh when constructed of two 'AA's. Although re-wraps offer very limited storage capacity, they are typically priced the same as
full capacity 'C' and 'D' batteries. There are very few brands of 9v size low self discharge batteries.
AccuEvolution (older version - AccuLoop) is one of the brands that offer
full capacity low self discharge batteries in all 5 common sizes: 9V-200 mAh, AAA-800 mAh, AA-2,200 mAh, C-4,500 mAh, D-10,000 mAh.
Full capacity low self discharge batteries are noticeably heavy. However, one should always read the specifications when shopping for low self discharge batteries. Because rewrapping and repackaging is a problem in the battery business, one may also wish to avoid low self discharge batteries that do not have the specifications clearly printed on the actual battery.
Charge retention
It is generally claimed that low self-discharge NiMH batteries retain 90% of their charge after six months, 85% after a year and 70% after two years, when stored at .
Other benefits
Low self-discharge NiMH batteries typically have a significantly lower internal resistance than traditional NiMH batteries. This has a number of desirable effects especially for high-drain applications:
- Voltage is more stable (less load- and capacity-dependent). This can have a beneficial effect on runtime in electronic devices, which typically have a cut-off voltage per battery that is not much lower than NiMH's nominal voltage. (However, this can also cause some devices with battery status indicators to overestimate the remaining capacity of a nearly drained cell.)
- Reduced heat buildup when the battery is quickly charged or discharged
- Higher efficiency
- Higher instantaneous current discharge capability
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