What's the best battery for laptop ?

When buying a replacement battery, the buyer often has the choice of different battery chemistries. Li-ion and Li-ion polymer batteries are used on newer phones, whereas the NiMH and NiCd are found in older models. If the buyer has a choice, the sales person may advise a customer to go for the highest capacity rating and to stay away from the NiCd because of the memory effect. The customer may settle for the slim-line NiMH because it offers relatively high capacity in a small package and is reasonably priced.

Is the Li-ion a better choice? Yes, for many applications. The Li-ion is a low maintenance battery which offers high energy, is lightweight and does not require periodic full discharge. No trickle charge is applied once the battery reaches full charge. The Li-ion battery can stay in most chargers until used. The charging process of a Li-ion is, in many ways, simpler and cleaner than that of nickel-based systems, but requires tighter tolerances. Repeated insertion into the charger or cradle does not affect the battery by inducing overcharge.

On the negative side, the Li-ion gradually loses charge acceptance as part of aging, even if not used. For this reason, Li-ion batteries should not be stored for long periods of time but be rotated like perishable food. The buyer should be aware of the manufacturing date when purchasing a replacement battery.

The Li-ion is most economical for those who use a laptop daily. Up to 1000 charge/discharge cycles can be expected if used within the expected service life of about two to three years. Because of the aging effect, the Li-ion does not provide an economical solution for the occasional user. If the Li-ion is the only battery choice and the equipment is seldom used, the battery should be removed from the equipment and stored in a cool place, preferably only partially charged.

more info:www.abatteryweb.com