One method for remotely starting an engine of a vehicle includes notifying, from the vehicle, a remote user of the vehicle that a battery of the vehicle has a charge level below a predetermined threshold. This method includes remotely starting the engine to charge the battery with energy from the engine upon receiving from the user a confirmation to start the engine. Another method includes remotely starting the engine in response to a command, from the user, to start the engine for preconditioning the vehicle. This method assesses charge level of the battery following engine start and adjusts engine-on time and vehicle settings to prioritize battery charge maintenance versus preconditioning based on the charge level.