Electric vehicle charging system
An external electric vehicle battery thermal management system is described. An electric vehicle thermal system provides external coolant to an internal battery thermal system of an electric vehicle. The internal battery thermal system includes a liquid-to-liquid heat exchanger to cool or warm the set of batteries of the electric vehicle. The external coolant is pumped through a first side of the heat exchanger and serves as the source to cool or heat internal coolant pumped through a second side of the heat exchanger. The external coolant and the internal coolant do not mix.
1 . A method, comprising:
receiving, from a battery management system of an electric vehicle, a request for external coolant to change a temperature of a battery of the electric vehicle;
determining a mass flow rate of cold coolant stored in a cold tank of an electric vehicle thermal system to pump through a first thermal loop of a first side of a liquid-to-liquid heat exchanger located on the electric vehicle, wherein the first thermal loop of the first side of the liquid-to-liquid heat exchanger does not mix with an internal coolant of a second thermal loop of a second side of the liquid-to-liquid heat exchanger located on the electric vehicle;
causing the determined mass flow rate of the cold coolant to pump through the first thermal loop of the first side of the liquid-to-liquid heat exchanger;
determining, based at least on a level of cold coolant stored in the cold tank and a level of hot coolant stored in a hot tank, whether to cause coolant returning from the first thermal loop to be cooled and stored in the cold tank or heated and stored in the hot tank; and
causing the coolant returning to be cooled or heated according to the determination.
2 . The method of claim 1 , wherein the request for external coolant includes a current temperature of the battery.
3 . The method of claim 1 , wherein the request for external coolant includes a requested temperature of the battery.
4 . The method of claim 1 , further comprising determining a mass flow rate of hot coolant stored in the hot tank of the electric vehicle thermal system to pump through the first thermal loop of the first side of the liquid-to-liquid heat exchanger.
5 . The method of claim 1 , wherein the external coolant is carried through a connector that connects an electric vehicle supply equipment (EVSE) with the electric vehicle.
6 . The method of claim 5 , wherein the connector includes a set of one or more power connections to carry power to charge the battery of the electric vehicle through the EVSE.
7 . The method of claim 1 , further comprising:
determining that there is an insufficient amount of the external coolant to change the temperature of the battery to a requested temperature; and
transmitting a response indicating an expected temperature of the battery after providing the external coolant over a certain period.
8 . The method of claim 1 , wherein causing the determined mass flow rate of the cold coolant to pump through the first thermal loop of the first side of the liquid-to-liquid heat exchanger further comprises:
causing a first control valve for the cold tank to open to a set point to achieve a determined temperature.
9 . The method of claim 1 , wherein determining whether to cause the coolant returning from the first thermal loop to be cooled and stored in the cold tank or heated and stored in the hot tank is further based on historical information of when hot or cold coolant is needed.