The following lines were added (+) and removed (-):
There are several "dry cell" rechargeable battery types including nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH) and lithium-ion (Li-ion). NiMH has replaced NiCd in most applications due to its higher capacity, but NiCd remains in use in power tools, two-way radios, and medical equipment. NiZn is a new technology that is not yet well established commercially.Standard refers to standard consumer sizes, such as A, AA, AAA, C, D, and 9v square batteries.A more disambiguous title, "''Rechargable Dry Cell Batteries of Standard Consumer Sizes''." These are mostly for portable electronics and other small consumer electrically powered products.Nickel metal hydride batteries recharge fewer times than NiCad and they perform very poorly in cold temperatures. Nickel metal hydride batteries recharge fewer times than NiCad and they perform very poorly in cold temperatures. Although NiMH batteries don't suffer from the memory effect that NiCd's have, they do have a less severe "lazy effect." The lazy effect is a weaker version of the memory effect. The lazy effect results from the crystallization of a portion of the nickel. Like the memory effect, the lazy effect prevents full use of the capacity in a rechargeable battery; both effects, however, can be avoided by using chargers with a discharge function. [[Image:lazyeffect.gif]]NiCad and NiMH batteries are amongst the hardest batteries to charge. Wheras with lithium ion and lead acid batteries you can control overcharge by just setting a maximum charge voltage, the nickel based batteries don't have a "float charge" voltage. So the charging is based on forcing current through the battery. The voltage do do this is not fixed in stone like it is for the other batteries. NiCad and NiMH batteries are amongst the hardest batteries to charge. NiMH batteries can require anywhere from 3 to 6 or more full deep and slow charging cycles before reaching their peak capacity. Wheras with lithium ion and lead acid batteries you can control overcharge by just setting a maximum charge voltage, the nickel based batteries don't have a "float charge" voltage. So the charging is based on forcing current through the battery. The voltage do do this is not fixed in stone like it is for the other batteries. If you need or prefer using a fast NiMH battery charger, it is important to use a fast charger that has been designed to charge quickly without overcharging or causing excess heat. ome cheap or poorly designed fast NiMH battery chargers will decrease the battery life by overcharging or generating excess heat. These are caused primarily by:* Not detecting the “End of Charge”; and,* Continuing to charge at a high rate.* Some NiMH Batteries cannot handle high charge currents; and,* When heat builds up, the NiMH Battery Charger fails to take appropriate action.=== Technology Advances ===New hybrid Ni-MH cells offer the convenience and shelf-life of alkalines, and the high-drain performance of older Ni-MH batteries. Today, the best rechargeable batteries are the new hybrid Nickel-Metal Hydride (Ni-MH) cells. These hybrid batteries have a lot going for them: they come fully charged (like alkaline batteries), and they can hold their charge over may months (unlike regular Ni-MH rechargeables). Because they can hold their charge for so long, they are suitable for low-drain devices like remote controls and flashlights.=== Brand Names === * Sanyo eneloop - Sanyo says Eneloops can be recharged up to 1000 times, and they will retain their charged capacity even after 6 or 12 months of storage. (According to Sanyo the specs are: 90% of charged capacity retained after 6 months, and 85% capacity after 12 months at 20 degree Celsius). The AA-sized (R6) batteries are rated at 2000 mAh, and the AAA-sized (R03) cells are rated at 800 mAh.* Powerex Imedion - Pre-Charged and Ready-to-use Rechargeable Batteries retain up to 85% of charge after one year of storage. [[Image:comparethemrechargebatts.gif]]* LaCrosse Technology BC-900 Alpha Battery Charger* Maha PowerEx “Ultimate Professional” Charger* Sanyo Eneloop Quick Charger - 2 AA batteries recharge in about 4 hrs.