Hey folks,

looking for a wee bit of advice.    I’m  having issues with the start stop and heated screen not working.  Previously I had issues with the chimes and a message on the touchscreen, these haven’t appeared in the past 2 weeks so I’m happy about that. 
 

When I use a multimeter across the battery, car off, it reads 12.3v.  If I use the engineering test menu, it says 11.7v, again with the car off, when running it jumps up to 14 odd v.

A dealer allegedly checked the battery whilst the chimes were coming through the dash and I had a message on the touchscreen stating “system off to save battery, start engine or turn off ignition”, and reported that the battery was “good” with a “good level of charge”.  
 

The car isnt running about as much as I used to, but I had it out for an hour and a half of continuous motorway cruising speeds on Friday. 
 

is the battery needing replaced?   

Update... after being out for a shorter run this afternoon, multimeter shows 12.5v on the battery, engineering test menu still reports 11.7v

would resetting the BMS help?  Could it be acting up?

Personally I would go ahead with a BMS reset if you have done any large amount of charging be it from driving the car or using a charging cable, rather than wait for the car to relearn the battery state itself as it can take some time.  I've read that the car can take somewhere in the region of 8 - 12 hours untouched before it will relearn the battery charge state by itself.

 

I've not had any ill effects from forcing a reset yet.

Don't rely on the engineering mode to read the voltage, known to be inaccurate. 

Thanks guys.   I’ll force the bms reset tomorrow.