1.       Necessity

Malfunction may be caused by the unstable Li-ion battery
structure when it is overcharged or overdischarged.
Accordingly, a protection circuit is necessary to fend off
this malfunction.

2. Principle

By monitoring voltage of each battery, charging or discharging
is limited by breaking the current when the monitored voltage
deviates from normal levels. The flow of current is cut off in
the case when the current flow is excessive.

3. Function : control the pack

1) Prevention of overcharge
2) Prevention of overdischarge
3) Prevention of over-voltaic current

4. Kind:

1) Smart form : Over-charge+over-discharge+over-voltaic
current+LED+Power Management
2) Dumb form : over-charge+over-discharge+over-voltaic current