Jaguar XF Sportbrake 2013, AGM battery charging voltages

[Devil Blades]

I am concerned my XF is over charging main battery, the Bosch battery I installed in April 2021 is now failing and I cannot find any accurate information regarding maximum voltage that an AGM battery should be charging at?

I have a voltage display on a cigarette adapter that shows a maximum of 14.8 mostly 14.7 whilst driving.

I have just installed a BM2 bluetooth monitor on both batteries and the software on my android phone that monitors them says it is charging at 14.94 and occasionally 15.01 volts and when you run the charging test on the software at the asked 2,500rpm it claims it is being over charged at 14.99volts.

So who on this forum knows the correct information as the internet varies wildly on what it should be.

Has anyone else tried using one of these battery monitors?

Phil

 

[Big John]

Hi Phil

14.8 whilst driving is normal. Also be aware that occaisionally the car will enter a diagnostic mode and deliberately discharge the battery to 75% capacity by limiting charging voltage to 12.2v. It does this to test capability of the battery to fulfil a stop-start restart.

My guess if the bluetooth monitor is over rearding slightly 🙂

John