Aux battery voltage

[Pompeyscouser]

Sorry to be a pain, but I remember some time ago seeing a post regarding how to view the aux Battery voltage somewhere in the on-screen Menus and I can’t find it. There was some selected button/switch actions required in Ignition mode but I can’t remember what it was. Any help would be appreciated. Thanks.

[reeac]

I don't know how to display that voltage on the screen but I bought a small digital voltmeter which I have permanently plugged into the cigarette lighter style socket in the central storage compartment. It only draws current when the car is in the "ready" situation. Don't use the USB socket as this is controlled at 9 volts, not Battery voltage. Following a couple of flat Battery episodes I always check that voltage under cold start conditions as I press the button. Readings are lower than I would expect ....never more than 12.0 volts and as low as 11.6 volts if the car has been left for a few days. Once the car is READY the voltage increases immediately to 14.3, eventually settling down to 14.0 after a while so the charging system is OK. I always understood that AGM batteries gave slightly higher output voltages than the 12.5 to 12.7 volts of conventional flooded cell ones but it seems not.

[Herbie]

1 hour ago, reeac said:

Don't use the USB socket as this is controlled at 9 volts, not battery voltage

It's actually 5V from a USB socket Roger.

 

[Geoffers]

Make sure headlights are off and not on automatic.

Switch ignition on single press.

Press and hold menu button. Turn lights on-off 3 times. (only first position lights). Release Menu button and you will see the full diagnostics. Give it a good 20 secs to complete the initial testing.

Quickest way out is just turn the ignition off.