The Delta-Voltage charger from Bosch quickly charges the battery and constantly regulates itself. When a battery begins to overcharge, the charger detects a characteristic voltage drop that is known as negative delta voltage.This value is used to trigger a drop in the charge current or to adjust the current down to a trickle charge, which prevents overcharging. The battery lifetime with this charger is about 1,400 to 1,500 charge/discharge cycles.
The Li-Ion Quick Charger completely charges Bosch Li-Ion batteries to 100%. 18 volts / 2.0 Ah in 30 minutes and 18 volts / 4.0 Ah in 45 minutes.