24 minutes ago, Jim H said:

What's wrong with CTEK chargers?

Is there something wrong with the CTEK charger ? That's news to me.

It is just possible it may cause the Stop/Start system to work. 😉

I must have mis-understood your answer. I thought you were being sarcastic in saying leave the charger in the cupboard as it's useless. Obviously not.

The CTEK charger is useful and have used it many times. As I said, I might get it out and give the battery a charge to see if it makes a difference to Stop/start, or maybe just wait until the warmer weather comes. I know there are lots of parameters that the car needs for SS to work, I'm sure temp is one of them.

34 minutes ago, Jim H said:

I know there are lots of parameters that the car needs for SS to work, I'm sure temp is one of them.

It is. What's baffling me at the moment is mine hasn't worked since July (and even in Yorkshire we do get the odd warm day, don't we) yet during a run of days this week when it's been 4° or less, mine has decided to start working again!😀

A question that just came up to my mind...

The MHEV Fiestas use the 48V battery for SS, right? Then why do they require EFB batteries and don't they just use cheaper conventional 12V batteries?

 

P.S. Also reading this thread I was surprised with all the issues you guys have with SS. I live in Finland which means that in the winter the temperatures can be harsh for the battery, but still, when it's over -5C or so, my SS always works (note: it gets the CTEK treatment every 2 months).

9 hours ago, AFS said:

A question that just came up to my mind...

The MHEV Fiestas use the 48V battery for SS, right? Then why do they require EFB batteries and don't they just use cheaper conventional 12V batteries?

That's an interesting question. According to various battery manufacturers sites, even if not needed for S/S, the EFB still has advantages in being better able to cope with a higher range of temperatures and the increasing electrical loads due to all the safety and convenience technology in modern cars.

Standard batteries may not be cheaper if buying huge bulk orders of EFB.  Though I am occasionally surprised by the seemingly unique parts on base models.

It's also for the variable rate charging though, standard lead acid doesn't like that.

MK8 2017 Zetec here. Lots of problems with battery drain, I kept a GooLoo jumstarter in the car at all times. Tried a Noco Genius 10 battery charger, but have been disappointed with it - the consensus seems to be that CTEK (which I've used previously) is superior, and Victron is possibly even batter.

Upgraded to AGM battery, reset the battery monitor manually, and set the battery type to AGM with Forscan and a vGate Vlinker FS USB, which needed a firmware update to work correctly.

An 096 AGM battery fits perfectly and adds a lot more CCA - 760 A.

Well, my run of Start/Stop working perfectly continues! It started to function on 9 February and has operated on every drive since, even though it's been mostly short journeys and I haven't given it a session on the charger since November.

This morning we made our first trip of the year up Wensleydale to our caravan. Numerous hold ups/roadworks en route but it operated throughout the journey, even with stops only a few hundred yards apart.

I was going to revert to my usual practice of turning it off (unless in Sport mode when it doesn't operate anyway) but I think I'll leave it for now just out of curiosity and see what happens. 

 

 

 

 

5 hours ago, Eric Bloodaxe said:

Well, my run of Start/Stop working perfectly continues! It started to function on 9 February and has operated on every drive since, even though it's been mostly short journeys and I haven't given it a session on the charger since November.

This morning we made our first trip of the year up Wensleydale to our caravan. Numerous hold ups/roadworks en route but it operated throughout the journey, even with stops only a few hundred yards apart.

I was going to revert to my usual practice of turning it off (unless in Sport mode when it doesn't operate anyway) but I think I'll leave it for now just out of curiosity and see what happens. 

 

 

 

 

I suspect it has something to do with it being a little bit warmer after a cold spell and the way that the BMS calculates things.

I have noticed my SOC reading increases on warmer days and goes down when it gets colder irrespective of how much I use the car within reason, except after very long journeys.

 

44 minutes ago, Tizer said:

I have noticed my SOC reading increases on warmer days and goes down when it gets colder

Yes, I can confirm my SOC does exactly that. 👍

2 minutes ago, unofix said:

Yes, I can confirm my SOC does exactly that. 👍

And to make you jealous @unofix I got my SOC up to 97% a couple of weeks ago. That was on the return journey of a 4 hour round trip and it was quiet warm that day. 

3 minutes ago, Tizer said:

I got my SOC up to 97% a couple of weeks ago

That is very impressive 👍

The best mine has ever managed is around 93% The only time it gets better than that is if I hook it up to the Maypole for at least 24 hours.

3 hours ago, Tizer said:

I suspect it has something to do with it being a little bit warmer after a cold spell and the way that the BMS calculates things.

I suspected that, but It doesn't explain why it didn't work from July last year until February. Even in Yorkshire we do get the odd warm day in "summer" as I believe it's called.😀

On 3/5/2025 at 11:47 PM, Eric Bloodaxe said:

but It doesn't explain why it didn't work from July last year until February.

Continuing the saga - it ceased to operate in July 2025 also, but made a return this morning and operated twice, in both cases after only a short drive.