Battery Care And Preservation
The effective battery life of a notebook may be improved by more than just the way in which it's used. Experience shows that careful handling of the battery itself helps to insure longer battery life and preserve it for more extended use.
Prevention Is Better Than Cure
As we've already mentioned, both NiCd and NiMH batteries are subject to the so-called memory effect, which kicks in after a specific period of use. This may be recognized by a reduction in battery capacity as usage time increases. This results from a transformation in the crystalline structure (crystal growth) of the active substances inside the battery cell. As a result, the internal resistance of the cell increases, so that voltage levels in the cell are smaller than those in a new battery. This also reduces the cell's ability to story energy, which is likewise diminished.
The best way to work around this memory effect is to disconnect the notebook from an external power source as soon as the battery is fully charged, and then to run off the battery. It's also important to avoid recharging the battery before it's fully discharged, if at all possible. As long as you're sure you won't need to use the battery, it's best to discharge it as completely as possible and then to store it in a cool dry place. Avoid high or below freezing temperatures. It's especially advisable not to store a fully-charged NiMH battery because that only increases the memory effect.