A vehicle electrical system includes a battery, a customer connection point, a switch electrically connected in series between the battery and the customer connection point, a computer communicatively coupled to the switch, and a transceiver communicatively coupled to the computer. The computer is programmed to instruct the switch to open in response to a state of charge of the battery decreasing below a charge threshold, receive an input selecting a time limit, and instruct the transceiver to transmit a message to a remote server upon determining that the state of charge of the battery will decrease below the charge threshold in less than the time limit from a current time.