Well my October 2019 Vignale has told me on numerous occasions (at least 45 times) that it has detected a CHARGING SYSTEM FAULT but today was the first time it would not start just a clicking sound from under the bonnet so its on charge at the moment. 

Eric mentioned above that he has had problems even after having his 2018 Fiesta on charge overnight well as far as I am concerned a new vehicle that has not even reached its first M.O.T. should not need to be put on a charger my first Focus 1.8 Zetec that I purchased new in Sep 1999 had its first replacement battery at nine years old.

At the risk of prolonging this thread that should have closed maybe you actually do have a charging system fault as indicated. That wasn't what was being discussed here.

Have you got a multi meter?

If so.....

Check battery voltage after it's sat overnight. Should be approx 12.6V +

Start car - get someone to raise the RPM to about 2500 and check the voltage again - charge voltage should be approx 13V to 16V.

This is a rough test and only used to get an idea if any issues are present. The exact output of the alternator should be confirmed by Ford.

15 hours ago, Midgeman said:

as far as I am concerned a new vehicle that has not even reached its first M.O.T. should not need to be put on a charger

Nail on the head there. When you’ve spent or are spending a whole load of ££££ for a brand new car you shouldn’t be having to charge the battery or use a multi meter . Straight back to the dealership with that. 

Is there a way to start the car once its into deep sleep mode ? Its been stood since the 23rd March. 

Went to use it today but no joy. Its allowed me to unlock the car and unfold the mirrors as it does once you press the key fob. Got in it and the dashboard was lit. Pressed the start button and nothing. Can't even lock the car atm or fold in the mirrors. Any advice or help appreciated. Mk 4 focus 1.5 Ecoblue manual. 

2 minutes ago, Wino said:

Is there a way to start the car once its into deep sleep mode ? Its been stood since the 23rd March. 

Went to use it today but no joy. Its allowed me to unlock the car and unfold the mirrors as it does once you press the key fob. Got in it and the dashboard was lit. Pressed the start button and nothing. Can't even lock the car atm or fold in the mirrors. Any advice or help appreciated. Mk 4 focus 1.5 Ecoblue manual. 

Clutch down and start button will it start?

Try putting the key in it's backup position between the gearstick and front USB/12V sockets.

5 minutes ago, alexp999 said:

Clutch down and start button will it start?

Try putting the key in it's backup position between the gearstick and front USB/12V sockets.

Tried that and nothing unfortunately. Ive took the key out of the fob to try to lock the car back up manually and can't turn the key with out excessive force and I dont want to force the key. 

The Ford Focus Mk4 should have a battery of 12v and 105 amp/hour, the same as most cars with start/stop, not the 12v and 60 amp/hour that it comes with. The bigger battery would provide enough energy to start/stop at all times. There is a regulator across the battery that limits the voltage available and is suppose to prevent a flat battery, but this would not be necessary if the correct battery was installed in the first place. FORD trying to save manufacturing costs?   Tim.

On 4/16/2020 at 2:22 PM, Wino said:

Tried that and nothing unfortunately. Ive took the key out of the fob to try to lock the car back up manually and can't turn the key with out excessive force and I dont want to force the key. 

The lock mechanism has not been lubricated periodically, a typical fault by many car owners. I suggest using thin gun oil, no any antifreeze liquids because they will make the problem worse.

On 1/11/2021 at 11:47 AM, TimF5 said:

The Ford Focus Mk4 should have a battery of 12v and 105 amp/hour, the same as most cars with start/stop, not the 12v and 60 amp/hour that it comes with. The bigger battery would provide enough energy to start/stop at all times. There is a regulator across the battery that limits the voltage available and is suppose to prevent a flat battery, but this would not be necessary if the correct battery was installed in the first place. FORD trying to save manufacturing costs?   Tim.

So have you replaced your Battery for the 12v 105amp and if so has it solved the problem ?? looking at other vehicles with start stop it appears that most have a 75amp to 85amp although 2020 Audi A4 3.0TDI has a 95amp.

4 hours ago, Freeze said:

The lock mechanism has not been lubricated periodically, a typical fault by many car owners. I suggest using thin gun oil, no any antifreeze liquids because they will make the problem worse.

If the lock cant operate properly without being lubricated on a car just a year old then Ford need to give their heads another wobble.

On 1/11/2021 at 11:47 AM, TimF5 said:

The Ford Focus Mk4 should have a battery of 12v and 105 amp/hour, the same as most cars with start/stop, not the 12v and 60 amp/hour that it comes with.

I may be wrong but I think the battery monitoring system/smart charge system will have been set up for the battery capacity that was originally fitted and may not work correctly with one of a different capacity. Maybe our resident Guru @JW1982 might have some suggestions on this.

Had my Focus since September and the start stop or keyless entry on any other door but the drivers and boot has never worked. When you went into the sub menu on the dash it has always said 'S/S not operating due to battery charging'.

Gave it until the start of January and then took it to Ford who diagnosed a faulty battery and ordered me a new one which ill have fitted next week. So hopefully this sorts my issue, but I have seen the message on the screen a few times regarding the ignition being turned off to save battery from the first page.

What Im glad i've seen on this thread thet I had no idea about was this 'tiny parking sensors' tone...

Now If this is what I think people are talking about then I had it on my previous Fiesta on 9 out of 10 drives, and the only way I can describe it is like there being a loose wire somewhere within the speakers and it sounding tinpot... like the sound is only coming out of half a speaker with no bass. I always thought this was the case and it being a battery issue never even crossed my mind..

However ive noticed it every now and again on my Focus (still thinking oh please tell me I don't have another loose wire connection somewhere..) So the fact im having a new battery fitted next week fills me with some hope that this will also fix this! 😀

What it does show however is that these batteries arnt very reliable considering the Fiesta was aa MK8 17 plate and the Focus is a 19 plate!

In all probability it's nothing to do with the battery, it's just that the BMS needs to be reset. Something Ford ought to be looking at, but in the meantime you can do it yourself. 

2 hours ago, FezMan said:

Had my Focus since September and the start stop or keyless entry on any other door but the drivers and boot has never worked. When you went into the sub menu on the dash it has always said 'S/S not operating due to battery charging'.

Gave it until the start of January and then took it to Ford who diagnosed a faulty battery and ordered me a new one which ill have fitted next week. So hopefully this sorts my issue, but I have seen the message on the screen a few times regarding the ignition being turned off to save battery from the first page.

What Im glad i've seen on this thread thet I had no idea about was this 'tiny parking sensors' tone...

Now If this is what I think people are talking about then I had it on my previous Fiesta on 9 out of 10 drives, and the only way I can describe it is like there being a loose wire somewhere within the speakers and it sounding tinpot... like the sound is only coming out of half a speaker with no bass. I always thought this was the case and it being a battery issue never even crossed my mind..

However ive noticed it every now and again on my Focus (still thinking oh please tell me I don't have another loose wire connection somewhere..) So the fact im having a new battery fitted next week fills me with some hope that this will also fix this! 😀

What it does show however is that these batteries arnt very reliable considering the Fiesta was aa MK8 17 plate and the Focus is a 19 plate!

Not had any issues with any of the keyless door operations even when I had the original battery they all worked. 

The battery that's on atm ( I checked yesterday with what was posted above about the battery) is a Varta N70 iirc.

Not had any further issues since the original one was replaced. 

One thing I will add though is I've noticed that the battery hasnt dropped below 11.5v regardless if the car has been left overnight or a few days so perhaps it is actually shutting down as it should.

Hi does anyone know what volts the battery should be at after standing  overnight on a 2021 Focus?