FMB204 Power supply voltage measurement accuracy


The reported external power voltage from my FMB204 is around 200mV off, measured on the battery of the vehicle (without load) with a calibrated Fluke. Is there any way to compensate this value or calibrate the FMB204 ?

Measured value / FMB204 reported value
11.92 12.151 0,231 V
12.31 12.552 0,242 V
12.4 12.602 0,202 V
12.44 12.647 0,207 V
12.49 12.687 0,197 V
13.99 14.126 0,136 V

Thanks in advance,


Hi Good day,

There is what we called an error margin in using Analog inputs.
The analog input error margin can increase if temperature varies.

For your reference please visit this link: FMC230 General description - Wiki Knowledge Base | Teltonika GPS (

Best Regards,
Maynard C.

Thanks that explains it and i didn’t expect this margin by design

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