hi again, battery is reading low, 11.70 -- after run to town and check 12.10 next morning 12 volts

charging voltage withengine running 15volts so looks like a cell going down

if i put it on charge (low charge rate) just as a test to prove if battery going down or I buy a new battery is there anything i need todo regards the ECU or BSI

ford C-Max titanium 2011 1.6 petrol 125hp model

thanks

If charging in the car then place the negative clip on the chassis earth, not the battery terminal.

If replacing battery with new then BMS needs to be reset. Ignition on (not engine). Press rear fog 5 times. Press hazard switch 3 times. Wait for battery warning light to flash on dash. Switch ignition off.

Edit - The above is for cars with a BMS. If the 1.6 petrol doesn't have stop start then it may not have a BMS. (Easy to see attached to negative battery clamp). If your car doesn't have a BMS then there's nothing to reset after a battery change.

You will have to reset the one-touch windows if disconnecting the battery on a Titanium.

thanks, god these new cars drive me mad

12 hours ago, the goat said:

thanks, god these new cars drive me mad

It's 15 years old!😄

the battery has a hand writtern date on it looks like july 23 or 25, so not old,but I've had batteries with 2yr warrenties that last only just over 2 years

voltage this morning 11.4 yesterday was 11.7

Don't forget the audio system keycode if that is relevant!!!

Being pedantic, batteries have multiple failure modes and if old it's capacity (very difficult to measure) that gets you but a dodgy cell may be the issue ...or not. A high discharge test may confirm but it isn't definitive as capacity means it can't repeatedly start the car:
https://www.batteryuniversity.com/articles/

27 minutes ago, Shearers said:

Don't forget the audio system keycode if that is relevant!!!

There won't be one on a 2011 C-Max.

7 hours ago, the goat said:

the battery has a hand writtern date on it looks like july 23 or 25, so not old,but I've had batteries with 2yr warrenties that last only just over 2 years

voltage this morning 11.4 yesterday was 11.7

As I have never had a battery that has got that low, I would suggest to either give it a good 12 hour on a battery charger to get it up to around 12.5 volts and see how it goes from there.

As I can't get my battery onto a charger without taking it out the car when it gets down to 12.4 volts I take it for a 10 mile drive on urban/country roads. This brings the charge right up and is good for just over a week.

tried to start car this afternoon NO go

got a new battery from local car spares willtry to fit it tomorrow

Well that makes my last comment null & void. Hope new battery cures your problem