11 hours ago, TheKesselRun said:

I naturally asked the rep who cancelled my subscription in the Ford CRC about if there is a known link with Ford Secure and the MK4.5 battery drain and obviously they denied it. 

I guess they would say that! You do wonder if this is why it's apparently being decommissioned shortly. 

It will be interesting to see how you go.on in the meantime!

 

I've looked at Ford Secure and I believe that the only way they can make it work is for the car to update the Ford servers more frequently than it does when only using the normal FordPass functions. Each connection from the car to the servers uses some battery capacity.

On 10/1/2025 at 2:53 PM, EmilC said:

Hi all,

I know this is an old topic, covering countless Ford models (including Fiesta, Kuga, who knows how many others). I noticed that the most common approach on the battery drain issue seems to be the "replace the battery with one made by Yuasa and change the SOC target". 
However, I have some additional information that I've never seen discussed before, and I think it worth being shared.

I own a 2024 Active X mHEV, which is affected by the "12V Battery low" issue since the first month. In my case. I won't dive into the relation with the service/dealer etc, it is irrelevant, they operated by he book provided by the mother company and, obviously, nothing wrong was found, for a few months. However, when the car reached the age of about 9 months, one of their battery tests indicated that the original 12 battery needs to be replaced. I want to underline this, that the battery reached an "no longer usable" rating from a certified Ford service unit after 9 months of ownership. Let's label this piece of information as A.

I've also learned about the glove box button issue (which doesn't break the contact every time), it was affecting me as well, but this is a small issue, because the glove box light power is cut after a few minutes after locking the car. This light doesn't stay lit for sufficient time to discharge the battery. 

The attempt to identify the root cause

I spend some time building a least-intrusive voltage logger solution, to find out what is happening, using a quite short sampling interval (1-5 seconds), which I've kept connected to the battery for extended periods of time, powered by an alternate battery. I wasn't able to make an accurate current logger, this would have become too intrusive, which I've avoided, therefore I've only relied on voltage information.

Taking the voltage into account, and the chart provided by @unofix, this logger provided interesting information, like a drop in voltage recurring once every hour when the car was parked, with the duration of 6 minutes on every occurrence. By doing some math, I ended up with the conclusion that the voltage drop can only be created by an electrical load of about 10 amps, and the drop was recurring with sufficient precision to consider this something which a) it is very likely controlled by software and b) operating on schedule, as programmed.

When does this thing stop? This recurring pattern ends when the battery reaches the "12V battery low" state, as a measure of protection. Again , this makes me think that what happens there is controlled entirely via software. It worth noting that there are exceptions from the pattern, in certain cases there is no recurring voltage drop every hour. I have no idea why. But, as a rule of thumb, the recurring voltage drop occurs more than half of the total time when the car is parked. The effect of this programmed activity is that the battery loses about 50% of its charge in less than two days. Let's label this piece of information as B. 

I wasn't able to find any link between this and other software/remote related settings. Turning remote start on and off didn't change anything, I also made an attempt to disable communications entirely, that didn't help as well. However, I have an active subscription for FordSecure (let's call this piece of info C)and real time maps, I believe these services are blocking the complete deactivation of all remote services.

Putting the things together

What matters here is that, from info A and B we can understand

• why the original batteries die very quickly - e.g. less than a year, instead of 4+. The programmed load wipes out discharge cycles out of the battery at a much higher rate, thus making the battery reach it's charge/discharge cycle count much faster. The problem doesn't seem to be caused by the accumulators, as much as it could be caused by excessive discharge, because of inefficient programming. 
• that replacing the battery with a larger one and setting the target SOC at a higher value doesn't solve the issue, it only makes it less visible. 

I suspect that FordSecure (C) could be the culprit, I work with software, and I think that it is very likely that a function like FordSecure reporting could be related to a recurring task running on the car.  I also know that the car is calling back home, as part of the 'Remote Features', and it does more things than we can see on the app dashboard. For example, I'm only able to see the mileage, the remaining fuel, oil life related info and tire pressure. But I'm pretty sure that additional info is sent, e.g.: battery battery levels.

As of now, the service still claims that this is not a known issue (which would have led to different issues, e.g. people suing the dealerships and claiming damages for known product faults)

What I'm suspecting is that the car does at least one of the following:

• powering up too many power hungry modules for telemetry, when it isn't actually required, neither demanded explicitly by the car owner. The car could be tasked to send too much information to Ford's servers.
• recurrently powering up required modules (e.g. to read tire pressure) through extremely power inefficient electronics.

And I also believe that Ford could fix that by analyzing the power waste, checking which modules are turned on by mistake, and adjusting the software to no longer activate them. And the badly engineered - and extremely inefficient - ones probably need to be redesigned.

Fiddle sticks got the annoying Ford Pass battery saver message. 😩

On 10/19/2025 at 11:22 AM, Eric Bloodaxe said:

I guess they would say that! You do wonder if this is why it's apparently being decommissioned shortly. 

It will be interesting to see how you go.on in the meantime!

 

It's been about 20 days since my Ford Secure subscription ended. Coincidence or not, I haven't seen any new "12V battery low" message. Just for my curiosity, I've put the logger to collect the battery voltage for a few days, and guess what, the hourly recurring voltage drop vanished. There was no other change done to the settings applied by the dealership (which are currently set to charge to 100SOC).

I can't enjoy more the fact that the battery doesn't drain anymore beyond "normal" levels, e.g. 0.08V/day, this means that I can usefully mount a camera with parking recording. 

I will probably ask the dealership to set the target SOC to 90% and charging current to a little bit more "normal" values, to avoid early wear of the battery. 

I just wanted to add my voice to the '12v battery low' error crowd.  It happens from time to time for me, and it's happened again this morning.  
 

 

5 hours ago, MrFrisky said:

I just wanted to add my voice to the '12v battery low' error crowd.  It happens from time to time for me, and it's happened again this morning.  
 

 

Could you please confirm whether you do have an active "Ford Secure" subscription? In my case, the issue went away along with FordSecure. 

I've never had Ford secure, but have had many battery low issues. I've started putting on charge regularly and that has stopped it.

My MK 4.5 is a 2024 model and warned about low SOC on the instrument cluster first the first time ever around 10 days ago (nothing via the app), interior lights stopped working but after 1 drive everything went back to normal.

 

Yesterday it totally refused to start, flashing cluster, lights, multiple warnings for module faults flashing up and a warning on Sync to start the car or turn it off to save battery.

 

I left it in the carpark and locked it with the fob, it made the mislock chirp on the horn so when I went to check the door it was interesting that keyless entry still worked which I would expect to be disabled if the battery was too low.

 

After 30 mins I went back and it finally started, albeit reluctantly, and it started fine again today but no warnings on the cluster or app about low SOC. 

 

Could this be a dying battery if the car isn't reporting the correct SOC or just another casualty of modern Ford motoring?

 

Worth nothing I drive about an hour each day and do not have ford secure subscription.

 

Thanks!

9 hours ago, hammie1911 said:

Could this be a dying battery

Yes.

Check the voltage at the battery terminals with a multi meter after the car has stood idle overnight. If it is less than 12.4V treat it to a new battery.

Check the battery. It either needs a good charge for a minimum of 12 hours, or you need a new battery.

On 11/11/2025 at 7:53 AM, pcaouolte said:

Yes.

Check the voltage at the battery terminals with a multi meter after the car has stood idle overnight. If it is less than 12.4V treat it to a new battery.

So, yesterday it wouldn't start...used a portable booster to get it going.

 

Drove 57 motorway miles and stopped for 15 minutes, it started ok. 

 

Drove a further 12 motorway miles and stopped for 30 minutes, it wouldn't start so needed the booster again. Finished the journey with 27 miles of mixed motorway and rural roads. 

 

Popped the bonnet last night so not to wake the car this morning and did the battery test today, it read 12.48 which I think is in the healthy range?

 

No warnings on the app or the cluster about SOC but getting more unreliable to start! I can't work it out. 

1 minute ago, hammie1911 said:

So, yesterday it wouldn't start...used a portable booster to get it going.

 

Drove 57 motorway miles and stopped for 15 minutes, it started ok. 

 

Drove a further 12 motorway miles and stopped for 30 minutes, it wouldn't start so needed the booster again. Finished the journey with 27 miles of mixed motorway and rural roads. 

 

Popped the bonnet last night so not to wake the car this morning and did the battery test today, it read 12.48 which I think is in the healthy range?

 

No warnings on the app or the cluster about SOC but getting more unreliable to start! I can't work it out. 

Sounds like there's a poor connection between some of the cells inside.  New battery will be the fix if so.

5 minutes ago, TomsFocus said:

Sounds like there's a poor connection between some of the cells inside.

I had a very similar issue last year with a Vauxhall Movano. Everything suggested that it was a battery issue, or even the cable from the battery to the starter motor (which is a known problem on the Movano). So one new battery and a complete new battery cable later and the random starting issue continued.

Usually you could get it started with the aid if a booster pack, which didn't seem to make much sense since the battery was brand new and fully charged. So following the advice of Sherlock Holmes, "When you have exhausted the impossible, whatever remains, however improbable, must be the truth" I gave in and replaced the Starter Motor.

One new starter motor later and the problem was at last fixed. Out of curiosity I took the old starter motor apart and found one of the windings partly burnt out.

 

1 hour ago, unofix said:

One new starter motor later and the problem was at last fixed. Out of curiosity I took the old starter motor apart and found one of the windings partly burnt out.

 

Interesting. The starter motor on my SEAT Leon turned out to be the culprit when the start/stop threw a wobbler at 3 days old (stopped but had to be restarted with the key, and couldn't disable the system.)

The starter motor was replaced under warranty but I was told "internal short".

On 11/11/2025 at 1:45 PM, unofix said:

Check the battery. It either needs a good charge for a minimum of 12 hours, or you need a new battery.

I have a comment on this. Based on my measured observations, the actual level when battery saver mode kicks in (keyless entry disabled on the right side etc) is at 11.85V / ~ 30% SOC. I can send you logged samples, if you want. 

On 11/11/2025 at 9:53 AM, pcaouolte said:

Yes.

Check the voltage at the battery terminals with a multi meter after the car has stood idle overnight. If it is less than 12.4V treat it to a new battery.

As Unofix subtly explained, 12.4 is not a level to worry about, it is the factory programmed target. Expect the voltage to never be greater than 12.4 unless you have reprogrammed the BCM to a higher SOC target or if the battery is charging (e.g.: the engine runs, you have plugged in a charger) 

And, lastly, I want to confirm once more that the 12V Battery Voltage Low message never appeared again on my car after FordSecure subscription has ended. It's been almost two months since then, I still drive short trips, nothing changed in my behavior. Previously I was seeing such messages at about every time when parking for more than two days (with initial SOC 100%) or even one day or less (with lower initial SOC) 

Hi, as you can see I am a newbie here.  Moved from BMW to Focus, and only slight regret is ridiculous  60ah battery in car crammed with tech.  Have read useful posts, and currently charging with Ctek on regular basis.  I am used to Bimmer code, but could use some advice on Forscan please.

I see that it is possible to change battery charge rate, but are there any tips which could help me from making a hash of the process?  All advice gratefully received.

Happy New Year to all my readers

 

2 hours ago, Murlass said:

I see that it is possible to change battery charge rate, but are there any tips which could help me from making a hash of the process?

The setting "State Of Charge" can be found in the Body Control Module (BCM). Factory default is usually set at 80%, just set this to 95% and click 'write'

Thanks Unofix, I'll  give that a go.  May even put a bigger battery in later, as I no longer drive everyday.

 

 

https://www.tayna.co.uk/

Usual recommendation is the Yuasa YBX7096

It is about 12mm taller than your standard battery but it apparently does fit the Focus Mk4.5

Me too started getting this 12V battery low message upon power up when the Focus Active X MHEV was only 12 month old. The common pattern is where the car is left parked for multiple days. Something is draining the battery while parked. My fix so far is to drive 20 to 30 miles every day (and it has to be everyday), which is miles I do not need. If do that then, I get back my courtesy lights and the battery warning does not happen. But I thought the BMS was logic there to save petrol? I just ordered the Maypole battery charger.

Edited December 28, 2025Dec 28 by david757

Fords just replaced my battery as part of warranty, but I do carry around a "4000A 12V Portable Car Battery Booster Jump Starter Power Pack" as a precaution - under £40 and gives piece of mind.

I covered my issue under 

 

Just to butt in on this battery subject. On the 22nd of this month I picked up my new Puma from the dealer. I asked him to put it on trickle charge for me. this he did, leaving it on for 20th and 21st.

I drove it home, 9 miles county/urban and attached my Rewire DB1 I also did a trip of 1.8 miles later that day to get the Xmas shopping in. After about 8 hours I took my first reading from the Rewire DB1 and have taken a voltage reading every morning since then. May I add the car has not run since the shopping trip on the 22nd. Below are the voltages I have got. Bit high to start with but voltage drop seems to be levelling off nicely at 0.02 volts even with the Rewire device on all the time. It's seems a far better battery than my other new Fiesta's and Puma. I am hoping I haven't opened my big mouth to soon.

22/12/	12.97
23/12/	12.88
24/12/	12.76
25/12/	12.70
26/12/	12.66
27/12/	12.62
28/12/	12.60

Update. Turned out the factory Ford Varta 60 Ah EFB battery was bad. It failed an out of curcuit work shop load test (fully charged). I donot know whether the battery was bad on day one or the Focus Active X MHEV 2024 sync 4 stingy discharge / charge logic made it go bad in the first 12 months. With a new fully charged Banner AGM 60Ah 650A battery now installed, I investigated with a multimeter. It turns out the system will allow the battery to discharge at 12.2V to 12.3V when you drive with low electrical loads. That is what a good 12.8V battery is brought down to when you first enter with the Sync 4 powered on with engine off. What is interesting is: tested with AC on and sports mode, if also you either turn "head" lamps on also, or blower to 5 or more then the car will charge the battery at 14.8V. If you run only heated seats or heated steering it with maintain only 12.6V to 12.8V. Turn it all off then the new battery was allowed to sit at 12.3V which I am sure is a new battery discharge. Looks like I will driving with head lamps on at lot more in good daylight.

 

58 minutes ago, david757 said:

With a new fully charged Banner

Is that what Poundland are selling these days ? 🤣

I would strongly recommend using Forscan to change battery SOC to 95% whether you upgrade the battery or not. It’s a relatively cheap and simple hack, just the price of the data cable, and at least your Focus will put a useful charge back into your battery; when you are driving.  Certainly helped with my Focus, but the basic problem remains that unless you use your car a lot, all that modern click, click, background magic will slowly drain your battery until it hits saver mode. A bigger battery probably increases the standing time but other than driving when I neither want or need to, I have reluctantly accepted that I just need to keep my Focus battery topped up with my smart charger.  It’s relatively easy for me, as I keep my car garaged when not in use.  🤔 Perhaps I should have bought a PHEV!?