Internal battery heating comprising a parallel and a series arrangement
An internal battery heating system includes an electrical conversion device electrically coupled to an electrochemical sub-cell or battery modules to form a heating circuit. The electrical conversion device alternately raises and lowers a voltage of the heating circuit to drive current between the heating circuit and the electrochemical sub-cell or battery modules. A controller commands the electrical conversion device to cyclically charge and discharge the electrochemical sub-cell or battery modules for internally heating the battery modules. Alternatively, a battery module may be electrically coupled to electrochemical sub-cells via pairs of switches to form a heating circuit. The pairs of switches are adapted for switching the heating circuit alternately between a parallel arrangement and a series arrangement to alternate charging and discharging of the battery module which results in internal heating of the battery module.
1 . An internal battery heating system comprising:
a core battery having a plurality of cells;
a heating circuit electrically coupled to the core battery, the heating circuit comprising a plurality of electrochemical sub-cells each electrically coupled to the heating circuit via a pair of switches, such that the plurality of electrochemical sub-cells may be alternated between a parallel arrangement and a series arrangement, wherein a quantity of electrochemical sub-cells in the heating circuit is at least one greater than a quantity of cells of the core battery; and
a controller adapted to provide coordinated switching of each of the pair of switches for each of the plurality of electrochemical sub-cells for alternating between the parallel arrangement and the series arrangement, such that the parallel arrangement provides the core battery with a higher voltage for discharging to the plurality of electrochemical sub-cells, and in the series arrangement, the greater quantity of electrochemical sub-cells in the heating circuit provides a higher voltage thereby discharging to the core battery for internally heating the core battery without the use of an electrical conversion device or an external power source.
2 . The internal battery heating system of claim 1 , further comprising a temperature sensor thermally coupled with the core battery and communicatively coupled with the controller for monitoring a temperature of the core battery.
3 . The internal battery heating system of claim 2 , wherein the controller commands coordinated switching of the pair of switches for each of the plurality of electrochemical sub-cells to cyclically charge and discharge the core battery based at least in part on the temperature of the core battery.
4 . The internal battery heating system of claim 2 , further comprising an indicator operatively connected to the controller and configured to indicate when the core battery has reached a minimum operating temperature.
5 . The internal battery heating system of claim 1 , further comprising voltage sensors electrically coupled to the core battery and the plurality of electrochemical sub-cells and communicatively coupled with the controller for monitoring voltages of the core battery and the plurality of electrochemical sub-cells.
6 . The internal battery heating system of claim 5 , wherein the controller commands coordinated switching of the pair of switches for each of the plurality of electrochemical sub-cells to cyclically charge and discharge the core battery based at least in part on the voltages of the core battery and the plurality of electrochemical sub-cells.
7 . The internal battery heating system of claim 5 , further comprising an over-voltage and current limiting device disposed in the heating circuit to prevent overcharging the plurality of electrochemical sub-cells.
8 . The internal battery heating system of claim 1 , wherein each of the pair of switches comprises one or more of a relay, a transistor, or a diode.
9 . The internal battery heating system of claim 1 , further comprising a heater-timer-enable switch operatively connected to the controller and configured to allow a user to remotely activate the internal battery heating system.
10 . The internal battery heating system of claim 2 , further comprising:
a control switch configured to switch the heating circuit off once the temperature of the core battery reaches a predefined temperature.