An LED condition indicator offers a quick glance of each battery's charge status:
Light Off: No battery
Solid Amber: Standby
Solid Red: Quick charge in progress
Solid Green: Fully charged
Flashing Amber: Over voltage / current protection activated, charging protection timer activated
Flashing Red: Charger fault
As Li-ion is memory free, batteries can be charged from any state regardless of the batteries' charge status. Each IDX Li-ion battery has its own built-in microprocessor which enables direct communication with the charger's program to individually select for each battery the correct charge program specific for that battery.
The charger features a built-in fan to prevent the unit from overheating.
As with all IDX chargers, the VL-4S's power switch is recessed to prevent an accidental loss of power. A worldwide, auto-sensing AC power (AC 100-240V) operation is standard.