Patent ID: 9728991
Date: 2017-08-08
CPC Classifications: H02J

Claim:
1. A method of charging a battery, the method comprises: supplying, by a power source, electrical power to a first charging control unit; supplying, by the first charge controlling unit, an essentially constant charging current of a predetermined first magnitude from a power source to the battery, during a first constant current mode of charging; switching, by a second charge controlling unit, to a second constant current mode of charging when a battery voltage reaches a predetermined threshold value; and supplying, by the second charge controlling unit, an essentially constant charging current of a predetermined second magnitude to the battery, during the second constant current mode of charging, wherein the second magnitude is lower than the first magnitude, wherein switching to a second constant current mode of charging comprises opening a switch which is arranged to open when the battery voltage reaches a predetermined threshold value, wherein the switch is arranged in parallel with a current limiting device, sourcing current into the battery when the switch is open, wherein the current limiting device comprises a component from the group comprising: a low power switch regulator and a linear regulator, and wherein the battery and second charge controlling unit are disposed within a robotic garden tool and the first charge controlling unit is disposed remote from the robotic garden tool.