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.