Initial Phase

Your Sparrow's 110-volt battery charger first converts the AC current to DC current. The first charging phase is the constant voltage phase. The constant voltage phase brings the battery pack voltage up to 192 volts and can take up to 5 hours. (If your Sparrow is equipped with a 220-volt battery charger this phase will take up to 2 hours.) The battery charger can draw up to 9 amps at 156 volts during this phase.

The RED LED in the center of the indicator indicates the battery pack is in the initial charging phase.

Equalization Phase

The second and last charging phase is the constant current phase. This is also commonly referred to as the equalization phase. The constant current phase begins once the battery pack reaches its gassing threshold at 192 volts. During the constant current phase, the charger draws a constant current of 2 amps with open voltage. After this equalizing charge runs for one hour, the battery charger will automatically turn off. However, if the Sparrow is left plugged in, you'll hear the fans running even if charging has finished. (If your Sparrow is equipped with a 220-volt battery charger, this last phase will still take 1 hour.)

The YELLOW LED in the center of the indicator indicates the battery pack is 80% charged.

Fully Charged State

The GREEN LED in the center of the indicator indicates the battery pack is fully charged.

In summary, your battery charger will run for enough time to replace enough electricity to bring your pack voltage up to 192 volts, and then the charger runs a 1-hour constant current equalization charge. Please use any opportunity to plug your Sparrow in for a recharge even if you do not have enough time to run the equalization charge.