General Warnings

OVMS is a hobbyist project, not a commercial product. It was designed by enthusiasts for enthusiasts. Installation and use of this module requires some technical knowledge, and if you don’t have that we recommend you contact other users in your area to ask for assistance.
The OVMS module is continuously powered by the car, even when the car is off. While the OVMS module uses extremely low power, it does continuously draw power from the car’s battery, so it will contribute to ‘vampire’ power drains.

Do not allow your car battery to reach 0% SOC, and if it does, plug in and charge the car immediately. Failure to do this can result in unrecoverable failure of the car’s battery.

The module can monitor the main and 12V battery and send alert notifications if the SOC or voltage drops below a healthy level.

Average Power Usage

The power used by the module depends on the component activation. You can save power by disabling unused components. This can be done automatically by the Power Management module to avoid deep discharging the 12V battery, or you can use scripts to automate switching components off and on.

The base components need approximately these power levels continuously while powered on:

Component Avg Power 12V Current
Base System 200 mW 17 mA
Wifi 330 mW 28 mA
Modem 170 mW 13 mA
GPS 230 mW 19 mA
Total 930 mW 78 mA

This adds up to:

  • ~ 22 Wh or 2 Ah / day
  • ~ 156 Wh or 13 Ah / week
  • ~ 680 Wh or 57 Ah / month

Note that depending on the vehicle type, the module may also need to wake up the ECU periodically to retrieve the vehicle status. Check the vehicle specific documentation sections for hints on the power usage for this and options to avoid or reduce this.