Hi everyone I’m very new to this forum please bear with me. I cannot afford garage bills at the moment so I’m trying my hardest to do what I can. I have a Ford Kuga 2016 180bhp Titanium. So my stop start hasn’t worked for a long time and I was noticing the voltage drops very fast when I stop as I have a voltage meter LED in the front when my charger is plugged into. So I got a new battery it’s for the vehicle and it is start/stop compatible. So I changed the battery ***** was good soon as I took it out start/stop worked again but I was noticing the voltage not going over 12.3v even on the motorway it would only increase when the car was rolling with my foot of the accelerator and I’d stop and still wouldn’t increase. So I’ve Google if I needed to do anything and I read reset the BMS I done that brill and I left it for more than 8 hours but it’s still doing the same. But today I put the AC on full and even when I was just parked up the voltage is at a steady 13.4 so I went back on the motorway and it was steady 13.3v with theAC on full but soon as I lowered the power the voltage drops? So it basically doesn’t increase when driving only when it seems to be using a lot of power with AC or heating etc. this wasn’t doing this before the battery was changed but the battery I thought needed replacing. so I was wondering if you very kind people could help me at all I would be very grateful.

thank you

Get the alternator checked out