Am I being stupid? Shouldn’t the battery test show the 48v battery and not the 12v?

50 minutes ago, Frequentfocuser said:

After returning the car on the third occasion, the stop/start no longer works.

Well, that is something useful that they have achieved. 🙂

If you are one of the few people who actually want it to work then charging the battery is usually the first thing to try (whatever the garage might say about it).

Edit to add:

Sorry I see from your more recent post that you were expecting to see a 48V battery, is your Focus an mHEV vehicle? I couldn't see a BISG in your photos but it might be the angle that the photo was taken from.

Edit again:

Sorry ignore me, I've now read the title of your post correctly, you have already said that it is an mHEV. 

15 minutes ago, Frequentfocuser said:

Am I being stupid? Shouldn’t the battery test show the 48v battery and not the 12v?

No, that is correct.  This type of charge tester is only for 12v.  Normal garages won't have the kit to check the 48v battery.

Ok thanks. So is it the 12v or the 48v battery that operates the stop/start

20 minutes ago, Frequentfocuser said:

Ok thanks. So is it the 12v or the 48v battery that operates the stop/start

The 48v battery restarts a warm engine via the generator & belt.

The 12v battery starts a cold engine using the conventional starter motor into the flywheel.  I don't know whether the starter motor is ever used for stop start on an MHEV, as SS should only operate on a warm engine.

However, what we have seen proven is that low 12v battery charge prevents the stop start from working even on an MHEV engine.  This does seem strange as we know the 12v system isn't usually used for stop start restarts.  But perhaps it is a failsafe, so that you would always have the option of using the starter motor even if the 48v generator can't restart the engine for any reason.

As you haven't been able to drive the car properly for a while, the 48v battery probably is depleted.  It'll take a bit of regen braking over a few drives to top that back up again.  The 12v battery does look ok from that test sheet.

Thank you so much. It’s had 2 x 1.5 hour drives but I’ll drive it for the next few days and see. I’m worried they have trapped a wire under the seat (as I know they’ve been under there cos the seat has an odd squeek for half hour or so after I got it back. Also when i looked under the car at the great exhaust place, I noticed they hadn’t put the engine tray or cat heat shield back on. Took it back (now 4th visit) and they put tray on but have lost the middle heat protector! So I have absolutely no faith in them now!