Equipment system comprising a battery-operated electrical device, a rechargeable battery unit, and a battery charger

A handheld tool electrically connectable to a battery unit for energy supply;

• the handheld tool comprising:
• a switch system within the handheld tool configured to control a current flow to an electric motor of the handheld tool from the battery unit on a plurality of supply lines;
• a receive unit within the handheld tool configured to receive a control signal from a signal line electrically connectable to a monitoring circuit of the battery unit;
• the switch system being controlled by an output of said control signal from the signal line of the monitoring circuit of the battery unit;
• and
• wherein the monitoring circuit is configured to detect at least one operating parameter of the battery unit, and from said at least one operating parameter, derive the control signal for controlling a current flow from the battery unit to the handheld tool.

A handheld tool comprising:

• a battery unit which is electrically connectable to the handheld tool, the battery unit comprising:
• a monitoring circuit configured to detect at least one operating parameter of the battery unit, and from said at least one operating parameter, derive a control signal for controlling a discharging process of the battery unit;
• said handheld tool comprising:
• an electric motor;
• a plurality of supply lines connected to the electric motor and connectable to the battery unit;
• a switch system configured to control current flow from the battery unit to the handheld tool on the plurality of supply lines;
• and
• a receive unit including a signal line configured to receive the control signal from the monitoring circuit of the battery unit;
• wherein the switch system is controlled by the control signal output of the monitoring circuit of the battery unit.

A handheld tool comprising:

• an electric motor;
• a detachable battery unit comprising a transmit unit configured to transmit a control signal to said handheld tool, the control signal containing information about an actual operating state of the battery unit,
• a plurality of supply lines electrically connected between the electric motor and the battery unit;
• and
• said handheld tool comprising a receive unit including a signal line configured to receive the control signal from the transmit unit of the battery unit.