Heya

I have a 71 plate focus 155bph MHev  that I’ve recently brought from a non Ford dealer. I’m getting a few battery issues with their car after 2/3 days where:

- the passenger door and boot keyless entry unlock stops working 

- an “System off to save battery“ error on the sync screen 

- FordPass becomes disabled.

This happens after about 3 days of no use.

The only item hard wired is a Nextbase dash cam.

Ive taken it back to the garage and they’ve had a look at the car and battery and found the battery to be okay but they don’t have access to Ford diagnostics systems. The only issue they’ve noticed is the nextbase dash cam stays on, but appears to turn off after 5 or so minutes. 
 

In my own testing with the battery is in the car, it’s about 12.22v but as soon as the headlights are turned on (LED) with the dashboard, the battery voltage drops to 11.70v (then throws me almost immediately a battery error after a couple of moments). I presume that shouldn’t be doing that voltage drop?

Is this likely to be a worn out battery that the garage doesn’t want to sort out? Or could it be something else?

I am aware there are significant issue with the battery here and while people have been changing the battery, I want to make sure it is the battery before I invest in a new battery.

 

Thank you 

Yes, it's the battery.

Though I would want to confirm for sure that the camera isn't staying on in a parking mode as that won't be helping.

I had two replacement batteries from ford after I bought my car (new) in the end I purchased a better battery myself Yahusa still find that after a few days of lack of use and if running the air con the battery charge drops to 12. (50%) So the  car shuts down to conserve mode.

i plug in my charger to top up. 

1 hour ago, TomsFocus said:

Yes, it's the battery.

Though I would want to confirm for sure that the camera isn't staying on in a parking mode as that won't be helping.

Is there a way to test the battery?

 

I am considering the battery upgrade but just want to make 100% it is the battery first.

 

the only issue I have is I cannot charge the battery. I have on street parking and a convent (which has been enforced talking to neighbours) that stop me from running cables over the pavement 

Remove battery from car? 

8 minutes ago, Andyr55 said:

Remove battery from car? 

Only concern I have with that was when the garage did it, it ended up having to be taken to Ford for a reprogramming job as it lost all its settings. 
they didn’t ask Ford to do a battery diagnostics though…

 

but supposedly when it did come out and was put on a battery tester the other day for a few minutes it read okay.

but wasn’t left out for more than 5 minutes as they didn’t want a repeat of losing settings 

 

the car has done less than 20,000 miles in 4 years also for context 

1 hour ago, captaincadet said:

a convent

Think you mean covenant - unless your neighbours are a group of nuns.

3 hours ago, captaincadet said:

Is there a way to test the battery?

 

I am considering the battery upgrade but just want to make 100% it is the battery first.

 

the only issue I have is I cannot charge the battery. I have on street parking and a convent (which has been enforced talking to neighbours) that stop me from running cables over the pavement 

Yes...the voltage test you've already done.  If it's dropping to 11.7v it's knackered.  Could be charged to get some more life out of it, but as that's not an option in your case, I don't know what else you're expecting apart from replacing it.

For what it's worth, I've charged mine using a large powerbank, so there are cable-free options for charging.

10 hours ago, TomsFocus said:

Yes...the voltage test you've already done.  If it's dropping to 11.7v it's knackered.  Could be charged to get some more life out of it, but as that's not an option in your case, I don't know what else you're expecting apart from replacing it.

For what it's worth, I've charged mine using a large powerbank, so there are cable-free options for charging.

To be honest I think I’m just wanting to make sure I’m not wasting my money on battery when it’s could be something else, especially when the garage was confident it wasn’t the battery until I questioned it

9 hours ago, captaincadet said:

To be honest I think I’m just wanting to make sure I’m not wasting my money on battery when it’s could be something else

The symptoms you describe are classic signs of low battery charge in my experience, particularly with the low annual mileage of the car.

If you replace the battery and the low usage continues, you're likely to be back in the same situation before too long.

If you really can't find a way to charge the battery (possibly doing it overnight if you have a relative or friend who can help with somewhere to park it off road?), you could try using the car a bit more. I've found that the classic "take it for a long drive" advice is not much help. Doing more short journeys in varied conditions giving the car lots of opportunities to charge when braking or on overrun, I've found more effective.

 

 

2020 mHEV 125

 

Similar issue with mine for over a year.

 

After a drive, all would be OK again.

 

Sorted this time last year ish (2024) now Sep 2025.

 

 

As far as I can gather.

 

The Battery Management System (BMS) monitors temp/volts/charging/discharging and only charges upto 80% ish of total battery capacity.

Quite complicated, it’s job is to reduce load on generating system and thus improve fuel economy.

 

Your voltage checks indicate 12.22V

This suggests that is with the engine off (ie not charging) or the BMS has turned off the charging.

With engine off, those voltage readings are not terrible.

I say that because the garage checked the battery – and battery good.

 

If the battery was U/S and/or not charging, very soon (a few of days of use) the car would not start.

---------- 

So what did I do?

Well, I’m too tight to buy a new battery.

**Fully charge the battery – using external charger.**

Connect the charger to the BMS module – not direct to battery post.

This ensures the BMS recognises a battery charge current.

------

You can’t do that. 

So, wait until you have completed a long 100m plus (preferably mainly motorway) daytime/cool journey (no headlights/aircon/10 inch off).

--------

**Reset the BMS**

Straight forward process – see youtube for examples.

 

All been good since.

 

 

Note 1:

 

The car only does 3.5K miles per year and mainly very short trips.

 

I did get the message again in June 2025.

 

I hadn’t external charged the battery/long journey since before Christmas.

 

No long journeys, so I’ve decided to charge the battery about every 3 months or so.

 

Simple for me – I have a drive.

 

 Note 2:

 

With regards to Ford diagnostic systems.

You will not need one of those.

There are a number of cheap (£25ish) OBD modules which can connect to a phone app.

 

These can be used to read/clear fault codes, battery voltage (engine off and engine running), and other stuff.

 

 

This has been a long one so in summary:

 

**Fully charge the battery – using external charger.**

 

**Restet the BMS**

 

Hope it works for you too.

 

7 hours ago, Eric Bloodaxe said:

The symptoms you describe are classic signs of low battery charge in my experience, particularly with the low annual mileage of the car.

If you replace the battery and the low usage continues, you're likely to be back in the same situation before too long.

If you really can't find a way to charge the battery (possibly doing it overnight if you have a relative of friend who can help with somewhere to park it off road?), you could try using the car a bit more. I've found that the classic "take it for a long drive" advice is not much help. Doing more short journeys in varied conditions giving the car lots of opportunities to charge when braking or on overrun, I've found more effective.

 

 

The low mileage was the previous owner. I tend to do 130 miles a week with a good 70 miles of that motorway 

 

I’ll try to get the garage again to replace the battery 

1 hour ago, captaincadet said:

a good 70 miles of that motorway 

As mentioned, that's not necessarily "good" in battery charging terms.

6 minutes ago, Eric Bloodaxe said:

As mentioned, that's not necessarily "good" in battery charging terms.

It’s a bit stupid that the cars set up like that. It shouldn’t need to be plugged into the wall every few weeks.

 

Not having a go at anyone here but it just seems like such a bad setup as it’s not like the cars unused 

 

 

6 minutes ago, captaincadet said:

It’s a bit stupid that the cars set up like that.

I think we all agree with that one! Even the (remarkably candid) service advisor at my local Ford dealer says the same!😀

There are plenty of threads where we go into more detail/have a good rant on the topic so I won't repeat it here.

it's not just a Ford issue, most modern cars have "intelligent" charging systems for environmental reasons, but they all seem to have similar issues unless your pattern of use exactly suits the system parameters. I've often linked to issues on Toyota, for instance:

https://www.toyotaownersclub.com/forums/topic/217673-12v-battery-maintenance-issues-etc/

Guess my best bet is try to get the garage to replace the battery and try my best with long distances or at least charge it when it starts to get low

8 minutes ago, captaincadet said:

Guess my best bet is try to get the garage to replace the battery and try my best with long distances or at least charge it when it starts to get low

Certainly, if the garage will stump up. They should reset the  BMS after fitting a new battery.

Don't know where you are in Wales, but (for example) a lap of Snowdonia would be better in battery charging terms than a steady drive along the M4.

Dear All,

Sorry to post another battery related issue but I wanted to get your thoughts before paying for a diagnostic. We have a mint 2019 Focus Vignale with just under 4,000 miles on the clock. She gets used about once or twice a week for short journeys but we've noticed over the last couple of months a few niggling electrical issues which come and go but have now culminated on 2 occasions with a flat battery, VERY flat in fact.  We called the AA out and he checked it over and showed us that the alternator and battery were bang on but something was draining the battery down after it was switched off and parked but he didn't have the software on his lap top to tell us what it was. He suggested keeping the cabin light switch set permanently to off as this wasn't turning off by itself after we closed the doors but this hasn't made any difference.

It's driving (!) us mad.

Any thoughts of a starting point?

I do realize that chasing an electrical drain problem could be very long winded and if we dropped it off at Fords it could be there for days with a hefty bill at the end of it and possibly no further forward.

Thanks so much.

You don't have an electrical problem, you have a major lack of use problem.

I'm amazed your battery has made it this far.

I make that 666 miles a year (coincidentally the number of the beast in Revelation 13:18), so undoubtedly the problem here.

 

I’ve read up and it seems that it doesn’t take much to kill these batteries now.

I’m actually suprised that they can survive being shipped and stored before being placed into a car

3 hours ago, captaincadet said:

I’ve read up and it seems that it doesn’t take much to kill these batteries now.

I’m actually suprised that they can survive being shipped and stored before being placed into a car

Mine was already in deep sleep mode on delivery day!

1 hour ago, TomsFocus said:

Mine was already in deep sleep mode on delivery day!

Let me guess new battery job or recoverable?

9 hours ago, captaincadet said:

Let me guess new battery job or recoverable?

I just put up with it.  Only went totally flat once, jump started and ran for 30 mins and was ok again. 

Sold the car just before 2 years old, I would be interested to know whether the new owner is still running the original battery.

Got the battery replaced a few weeks back. Battery sits very comfortably at 12.4v

 

not a single battery state warning even without a weeks of use!