TEMPERATURE DEPENDENT FUSE FOR BATTERY COOLING SYSTEM
Systems and methods for overheating protection in a liquid cooled vehicle battery are disclosed. Systems can include a battery housing enclosing at least one electrochemical cell and a temperature dependent fuse connected in series with the at least one electrochemical cell. A cooling system may circulate liquid coolant through the battery housing. In the event of a cooling system failure, the temperature dependent fuse may blow before the temperature of the at least one electrochemical cell increases enough to damage the battery.
1 . A battery protection system comprising:
a housing enclosing at least one electrochemical cell and a temperature dependent circuit interrupting element connected electrically in series with the at least one electrochemical cell; the temperature dependent circuit interrupting element having a continuous current capacity that decreases as the temperature of the circuit interrupting element increases, and
a coolant within the housing, the coolant in thermal contact with at least a portion of the temperature dependent circuit interrupting element.
2 . The battery protection system of claim 1 , wherein the circuit interrupting element is immersed in the coolant.
3 . The battery protection system of claim 1 , wherein the housing encloses a plurality of electrochemical cells connected electrically in series.
4 . The battery protection system of claim 1 , wherein the housing encloses a plurality of electrochemical cells connected electrically in parallel.
5 . The battery protection system of claim 1 , further comprising a pump and a heat exchanger in fluid communication with the housing.
6 . The battery protection system of claim 1 , wherein the temperature dependent circuit interrupting element comprises a resistive metal.
7 . The battery protection system of claim 1 , wherein the temperature dependent circuit interrupting element is configured to open without requiring a temperature measurement.
8 . An electric vehicle with a battery cooling and protection system, the vehicle comprising:
at least one electric motor;
a liquid cooled battery system for powering the at least one electric motor, the liquid cooled battery system comprising a battery in thermal contact with a liquid coolant; and
a battery protection system comprising at least one temperature dependent circuit interrupting element in thermal contact with the liquid coolant, the circuit interrupting element arranged in series with the battery and having a continuous current capacity that decreases as the temperature of the circuit interrupting element increases.
9 . The electric vehicle of claim 8 , wherein at least a portion of the circuit interrupting element is disposed within the liquid coolant.
10 . The electric vehicle of claim 8 , wherein the liquid cooled battery system contains a first amount of liquid coolant having a first temperature during operation of the electric vehicle.
11 . The electric vehicle of claim 10 , wherein the liquid cooled battery system is configured such that when the liquid cooled battery system contains a second amount of liquid coolant that is less than the first amount of liquid coolant, the temperature of the second amount of liquid coolant increases to a second temperature that is greater than the first temperature.
12 . The electric vehicle of claim 8 , further comprising a battery housing, wherein the battery and the temperature dependent circuit interrupting element are enclosed within the housing and wherein at least a portion of the liquid coolant is configured to flow through the housing.
13 . The electric vehicle of claim 8 , wherein the battery comprises at least one string of battery modules connected in series.
14 . The electric vehicle of claim 13 , wherein the liquid cooled battery system is configured to move liquid coolant through the at least one string.
15 . The electric vehicle of claim 13 , wherein the battery comprises a plurality of strings, each string having at least one temperature dependent passive circuit interrupting element.
16 . The electric vehicle of claim 8 , wherein the temperature dependent circuit interrupting element comprises a resistive metal.
17 . The electric vehicle of claim 8 , wherein the circuit interrupting element is configured to open without requiring a temperature measurement.
18 . A battery protection apparatus comprising:
means for enclosing at least one electrochemical cell;
means for interrupting a circuit connected electrically in series with the at least one electrochemical cell, the circuit interrupting means configured to interrupt the circuit when a current greater than a continuous current capacity travels through the circuit interrupting means; wherein the circuit interrupting means has a continuous current capacity that decreases as the temperature of the circuit interrupting means increases; and
means for cooling the at least one electrochemical cell and the circuit interrupting means.
19 . The battery protection apparatus of claim 18 , wherein the circuit interrupting means is selected from the group consisting of a fuse, a fusible link, a resistor, a thermistor, a thermal fuse, and a thermal cutoff.
20 . The battery protection apparatus of claim 18 , wherein the circuit interrupting means is configured to open without requiring a temperature measurement.
21 . A method of battery over-temperature protection comprising immersing one or more electrochemical cells and at least one temperature dependent circuit interrupting element in a common liquid coolant.
22 . The method of claim 21 , comprising enclosing the one or more electrochemical cells in a common housing.
23 . The method of claim 22 , comprising circulating the common liquid coolant through the common housing.
24 . The method of claim 21 , wherein the at least one temperature dependent circuit interrupting element is a metallic fuse.