BATTERY PREHEATING SYSTEMS AND METHODS IN AN AIRCRAFT HYBRID ELECTRIC POWERTRAIN

A battery heating system for a hybrid aircraft powertrain includes a combustion engine, a battery pack, a combustion engine coolant circuit, and a battery pack coolant circuit. The battery heating system further includes a heat exchanger configured to exchange heat between the combustion engine coolant circuit and the battery pack coolant circuit. The battery heating system further includes at least one throttling device operatively connected to one of the combustion engine coolant circuit or the battery pack coolant circuit. The battery heating system further includes a controller configured to transmit a signal to the at least one throttling device to adjust a flow of coolant through the heat exchanger of at least one of the combustion engine coolant circuit or the battery pack coolant circuit.