How do we charging the Lithium Ion Battery (1)? How do we charging the Lithium Ion
Battery (1)? The Li-ion
charger is a voltage-limiting device similar to the lead acid
battery charger. The difference lies in a higher voltage per cell, tighter voltage tolerance and the absence of trickle or float charge when full charge is reached. While the lead acid
battery offers some flexibility in terms of voltage cut-off, manufacturers of Li-ion cells are very strict on setting the correct voltage. When the Li- ion was first introduced, the graphite system demanded a charge voltage limit of 4.10V/cell. Although higher voltages deliver increased energy densities, cell oxidation severely limited the service life in the early graphite cells that were charged above the 4.10V/cell threshold. This effect has been solved with chemical additives. Most commercial Li-ion cells can now be charged to 4.20V. The tolerance on all Li-ion
batteries is a tight +/- 0.05V/cell. Industrial and military Li-ion
batteries designed for maximum cycle life use an end-of-charge voltage threshold of about 3.90V/cell. These batteries are rated lower on the watt-hour-per-kilogram scale, but longevity takes precedence over high energy density and small size. more info:
www.good-battery.co.uk