53 minutes ago, Miniman said:

I'll get on and order the mighty Yuasa

It will need to be charged for a minimum of 12 hours before it is fitted to your car.

16 hours ago, Miniman said:

If I buy and fit the Yuasa battery recommended (YBX7096), will the BMS need recalibrating and if so, can that be easily done?

I'm not ready to use FORscan yet as I need to research how to change the battery SoC with messing anything else up!!

Do you really need a new battery on your 2025 Focus?  I know that the Yuasa YBX7096 is a widely recommended upgrade for the rather weak OEM Ford fitted battery, but you might just find that altering your target state of charge is sufficient to resolve your problems; at least to an acceptable point. As you've bought the cable it might be worth a shot before you splash out on another battery.  

I'm more satisfied with my 2023 weakling OEM battery since running the Forscan hack. Yes, it still needs an occasional top up charge, because of my low mileage, but much less so. I suspect that I'd still need to occasionally top up the uprated battery.  

The useful video that @unofix has shared on how to reset the BMS after a battery replacement, also suggests that you would reset the BMS after charging.  Unless I am mistaken, I believe that the BMS should not be reset after a simple recharging. As always, I'm happy to be corrected!

10 minutes ago, mad-mushroom said:

Do you really need a new battery on your 2025 Focus? 

Hopefully the profile year is wrong.  If it genuinely is 2025, even Ford should cover that under warranty.

(Appreciate it may have sat in a compound for months, but even so...)

11 minutes ago, mad-mushroom said:

Do you really need a new battery on your 2025 Focus?  I know that the Yuasa YBX7096 is a widely recommended upgrade for the rather weak OEM Ford fitted battery, but you might just find that altering your target state of charge is sufficient to resolve your problems; at least to an acceptable point. As you've bought the cable it might be worth a shot before you splash out on another battery.  

I'm more satisfied with my 2023 weakling OEM battery since running the Forscan hack. Yes, it still needs an occasional top up charge, because of my low mileage, but much less so. I suspect that I'd still need to occasionally top up the uprated battery.  

I got a battery for a good price (just under 95 quid), so I've ordered that, and will charge it for a minimum of 12 hours as Unofix recommended.

I'm still pretty saddened by the fact that a brand new 2025 car should need it's battery charge topped up occasionally. My '72 Mini doesn't even need this and I only you it occasionally.

Thanks for your thoughts though. 

3 minutes ago, TomsFocus said:

Hopefully the profile year is wrong.  If it genuinely is 2025, even Ford should cover that under warranty.

(Appreciate it may have sat in a compound for months, but even so...)

No the year is correct Tom. The car has been back to the supplying dealer 3 times now, who reprt no DTCs and no issue with the battery. I'm persistent in trying to get the sunroof to operate correctly as my 2020 Vignale sunroof always operated correctly and it's exactly the same roof.

I'm afraid I've lost confidence in the dealer who told me "the sunroof switch can be a bit twitchy at times". No matter how I persist with them I cannot get them to change either the battery (reported to be OK on their test kit) and/or the sunroof switch.

So my plan is the Yuasa battery and a BMS reset. If this helps, then I'll grow a pair and try my hand at the 95% SoC change in Forscan! 

2 hours ago, Miniman said:

....

still pretty saddened by the fact that a brand new 2025 car should need it's battery charge topped up occasionally. My '72 Mini doesn't even need this ....

It's a modern day car problem, and is exacerbated if you are a low mileage driver, like me.  Even my 2016 BMW Mini Clubman Cooper D, with a much beefier battery, needed an occasional top up (after I retired and my mileage dropped) particularly during winter months. However, the need was much less obvious than with my 2023 Focus where interior lights and various other functions are disabled when it falls into 'battery saver' mode.

Perhaps this is a deliberate design flaw to help us get used to regularly plugging our cars into the electrical grid –– it's all part of the great EV revolution!

2 hours ago, Miniman said:

My '72 Mini doesn't even need this and I only you it occasionally.

Lol, an old Mini (I had a '62 to start with, then 2 x70's versions) wasn't stuffed with the cr*p (sorry, "features") that we enjoy in modern cars, though!😀

4 hours ago, mad-mushroom said:

also suggests that you would reset the BMS after charging.  Unless I am mistaken, I believe that the BMS should not be reset after a simple recharging.

You are indeed correct. The BMS should only be reset after a NEW battery (or perhaps a good used battery) has been fitted and it should never be reset just because the battery has been charged.

To be honest I'd not noticed the incorrect commentary at the beginning of video regarding the "resetting of the BMS after charging" until you pointed it out. Thank you for that, and I will have to add a corrective statement to that video clip when using it in the future.

 

4 hours ago, mad-mushroom said:

It's a modern day car problem, and is exacerbated if you are a low mileage driver, like me.  Even my 2016 BMW Mini Clubman Cooper D, with a much beefier battery, needed an occasional top up (after I retired and my mileage dropped) particularly during winter months. However, the need was much less obvious than with my 2023 Focus where interior lights and various other functions are disabled when it falls into 'battery saver' mode.

Perhaps this is a deliberate design flaw to help us get used to regularly plugging our cars into the electrical grid –– it's all part of the great EV revolution!

You may very well be right about that!!!

3 hours ago, Eric Bloodaxe said:

Lol, an old Mini (I had a '62 to start with, then 2 x70's versions) wasn't stuffed with the cr*p (sorry, "features") that we enjoy in modern cars, though!😀

The electrical c**p (features) in my old Mini runs to lights, wipers and a heater blower and that's it. It doesn't even have a heated rear screen to keep your hands warm when you have to push it lol

13 hours ago, Miniman said:

The electrical c**p (features) in my old Mini runs to lights, wipers and a heater blower and that's it.

You can tell it must be a BMW Mini.

No mention of indicators 🤣

Evening guys,

The new Yuada battery was delivered yesterday and has been on charge overnight and all of today on CTEK smart battery charger. The charger is now at the maintaining charge step. With the charger removed, I measured the resting voltage at 13.3v. This seems to be a full 1v higher than the current battery in the car.

I aim to fit the new battery tomorrow then reset the BMS.

Cheers, Steve.

2 minutes ago, Miniman said:

Evening guys,

The new Yuada battery was delivered yesterday and has been on charge overnight and all of today on CTEK smart battery charger. The charger is now at the maintaining charge step. With the charger removed, I measured the resting voltage at 13.3v. This seems to be a full 1v higher than the current battery in the car.

I aim to fit the new battery tomorrow then reset the BMS.

Cheers, Steve.

It won't be at 13.3v tomorrow.  More like 12.8v. 

11 minutes ago, Miniman said:

The new Yuada battery

May the force be with you young Jedi 🎉

21 minutes ago, unofix said:

May the force be with you young Jedi 🎉

🤣🤣

Evening guys,

Going to fit the new Yuasa battery in the morning. Do I need to reset anything else apart from the BMS once it's fitted?

Is there a step-by-step instruction on setting the SoC in Forscan?

Cheers, Steve.

On 6/30/2025 at 3:52 PM, mad-mushroom said:

It's a modern day car problem, and is exacerbated if you are a low mileage driver

I suspect low RPM is not helping that either. My car (1L ecoboost) tells me to go 5th gear at about 1500 rpm (~55 km/h) if I release the pedal a bit, the "engine break" is non existents and the computer probably thinks driving is easy. Constant low RPM is not charging my battery. It means no more Start/Stop ...and that's a catch 22. I'm not investing in a charger to save 5 cents of petrol a year.🙃

2 hours ago, Ponch said:

I suspect low RPM is not helping that eithe

The Alternators fitted to modern cars are massively over specified and are modulated to never or hardly ever run at their full Charging Capacity. so low RPM makes little if any difference. 

Unfortunately I'm old enough to remember when dynamos were still commonplace and alternators were replacing them. 

With a dynamo, at idle, you would often see the charge light flicker, or get a zero or negative reading on the ammeter, if you had one.

The big advantage of the alternator was that it gave a good charge even at very low revs, including  tickover.

 

@Miniman how did it go with the battery change, did you use Forscan to change the battery target SOC? I’d be interested in hearing how things went, as although my OEM battery seems to be behaving well since setting to 95%, I suspect that I might be looking to fit a beefier battery this winter. 

Hi Mike,

I've not fitted the battery yet as I have opened a case with Ford-CRC. I'm still not happy with the sunroof "vent" function which works sometimes and not others.

Until Ford resolves this issue, I'm inclined to leave the car as is. Once it's resolved, I'll fit the new battery and reset the BMS.

Cheers, Steve.

That’s interesting @Miniman  I’m pretty sure that my sunroof operation is much the same, as getting the vent position seems pretty hit & miss. It’s not really worrying me too much as I do tend to go for fully open or closed but I agree that if it venting is a function that is supposed to work, then it really should work properly.

Hi Mike,

That's curious that your sunroof is the same, especially as you have the same model as me! The owners manual categorically states that the sunroof has a "vent" function, which is achieved by pressing the sunroof switch first.

Out of interest, does your sunroof vent correctly if you use the global opening function on your keyfob? Mine works correctly 100% of the time. I'm assuming for this, the sunroof just receives a signal of a predetermined length to vent the sunroof, which is where my theory of an iffy switch comes from!

My case with Ford CRC UK has become more interesting, the technical dept have sent me the instructions on how to operate the sunroof, as if they thought i didn't know how to! 

Sadly, I can see me giving up on this, as they really don't know what to do. All I know is that my 2020 Vignale sunroof operated correctly, so For must have a batch of duff sunroofs or switches.

I can see myself fitting the Yuasa battery, resting the BMS and carrying on. At the end of the day, if I want the sunroof vented, I can use the keyfob.

Cheers, Steve. 

On 7/29/2025 at 2:12 PM, Miniman said:

Out of interest, does your sunroof vent correctly if you use the global opening function on your keyfob?

TBH, I didn't know that using the key fob was an option. It doesn't seem to appear in the online user manual, or at least I haven't found it. Having now seen a YouTube demo I will try it out sometime.

As mentioned in an earlier post, I'm not too bothered about the venting function but do agree that when something is supposed to work – it should. And like you, when I've tried to use vent only the success rate has been very low. I hope that you can get a more satisfactory response from Ford CRC UK, but I suspect that you will just get 'fobbed off ' (tentative pun intended).

re: changing battery target SOC with Forscan – like others on this forum, I highly recommend that you do this. Since adjusting to 95% I've experienced far fewer 'battery saver' issues, and a much reduced need to do 'top up' mains charging. I haven't yet found the need to upgrade from the original weakling battery; but accept that might well change in the winter months.