Output voltage Volvo V90CC Pro

[trignflo]

I had a thinkware F770 dual dashcam professionally fitted to my V90CC including a thinkware external battery to reduce potential low battery voltage issues.

All worked well for a couple of months then recently all stopped working. I've checked the external dash cam battery and the warnings lights are on for too high voltage (16V) g into the battery.

Multimeter on inputs show 16V coming in which seems to high. I thought I would connect via the rear tunnel console but that is also giving me an output of 16V. When connecting via a cigar lighter plug.

On my 3 month check up I don't think there was as software update.

Does anyone know or can tell me the output voltage from the rear tunnel console on their V90?

[SwissXC90]

Cars with AGM batteries charge at higher voltages than flooded lead-acid batteries.

And the lower the temperature, the higher the charge voltage

A charge voltage of 15.3V at 0°C is normal.
Potentially higher at colder temperatures.

If you are concerned with overvoltage, check the voltage at the end of a drive when the battery has charged up to near full charge, and at best when the temperature is higher.
Also, add some load such as headlights and rear window demisters to see what the alternator will settle to.