Does an OBD tracker drain the car battery? How to test
Whether a tracker drains a battery depends on the vehicle, the idle period and the device, so test it. It can add a draw, and how much depends on the combination. ReWheel FMS connects supported vehicle information with equipment and operational records for field and institutional operations.
What decides the draw
Check these first
- Vehicle sleep behaviour: some vehicles keep the diagnostic port powered while parked.
- How many days the vehicle sits without starting.
- Battery age and condition.
- Device standby behaviour, which must come from the supplier in writing for your device and vehicle.
A tracker that is fine on a vehicle driven daily may behave differently on a vehicle that sits for weeks. Test the case you have.
A seven-day parked test
Record these readings
- Resting battery voltage before fitting, after a full day parked.
- Voltage at the same time each day for seven days without starting the vehicle.
- Whether the vehicle starts normally on day seven.
- The device report times, so you can see whether it kept reporting while parked.
- A control: the same readings for a similar vehicle parked for the same seven days without the device, because a parked vehicle loses some voltage on its own.
If a vehicle sits for weeks
Set a rule before fitting: for example, a maximum number of idle days before a vehicle is checked, started or disconnected. Record who owns the rule.
Seven-day battery test log
Replace the example readings with your own. The values only show the format and are not a measurement of any device.
On a small screen, scroll this table horizontally. Keyboard users can focus the table region and use arrow keys.
| Day | Resting voltage with device (V) | Control vehicle without device (V) | Vehicle started | Device reported while parked |
|---|---|---|---|---|
| 0 (before fitting) | 12.6 | 12.6 | Yes | Not applicable |
| 1 | 12.5 | 12.6 | No | Yes |
| 3 | 12.4 | 12.5 | No | Yes |
| 5 | 12.3 | 12.5 | No | Yes |
| 7 | 12.3 | 12.4 | Yes | Yes |
What ReWheel provides
ReWheel FMS connects supported vehicle information with equipment and operational records for field and institutional operations. Vehicle compatibility, data-access requirements, connectivity and installation are assessed per deployment, never assumed.
Continue with ReWheel: OBD, hardwired and battery GPS trackers compared
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