Charging
LiPoly batteries must be charged carefully. The basic process is to charge at constant current until each cell reaches 4.2 V; the charger must then gradually reduce the charge current while holding the cell voltage at 4.2 V until the charge current has dropped to a small percentage of the initial charge rate, at which point the battery is considered 100% charged. Some manufacturers specify 2%, others 3%, but other values are also possible. The difference in achieved capacity is minute.
Balance charging simply means that the charger monitors the voltage of each cell in a pack and varies the charge on a per-cell basis so that all cells are brought to the same voltage.
Trickle charging is not recommended for lithium batteries. Most manufacturers claim a maximum and minimum voltage of 4.23 and 3.0 volts per cell. Taking any cell outside these limits can reduce the cell's capacity and ability to deliver full rated current.
Most dedicated lithium polymer chargers use a charge timer for safety; this cuts the charge after a predefined time (typically 90 minutes).
Read more about this topic: Lithium Polymer Battery
Famous quotes containing the word charging:
“Faster than fairies, faster than witches,
Bridges and houses, hedges and ditches;
And charging along like troops in a battle,
All through the meadows the horses and cattle;”
—Robert Louis Stevenson (1850–1894)
“You must neither add anything to what I command you nor take away anything from it, but keep the commandments of the LORD your God with which I am charging you.”
—Bible: Hebrew, Deuteronomy 4:2.
“... from Russia I didn’t bring out a single happy memory, only sad, tragic ones. The nightmare of pogroms, the brutality of Cossacks charging young Socialists, fear, shrieks of terror ...”
—Golda Meir (1898–1978)