US Patent 11529886 Power supply during vehicle off state

A power system for a vehicle includes a control module, a low-voltage battery electrically coupled to the control module, a high-voltage battery electrically coupled to the control module, an engine electrically coupled to the high-voltage battery, and a computer. The computer is programmed to, while the vehicle is in an off state, in response to a pending download to the control module, provide power to the control module with one of the low-voltage battery, the high-voltage battery, or the engine upon determining whether the low-voltage battery and the high-voltage battery have sufficient charge to power the control module for the download.