Mk4 negative for charging

[RMurphy195]

Just now, unofix said:

Hello @RMurphy195 an interesting little study. I know somewhere you may have already given these details but can you just confirm these points please:

What Ah size battery is fitted ?

What Ah size battery is actually set in your vehicles software ?

What do you currently have the SOC set to ?

 

Have only just received my ELM327 so haven't connected up to Forscan yet but will read off (and hopefully store) these details once I'm confident with the kit. Supposed to be 70ah but you never know!

[Wino]

Mine works within half a mile even with cold temps @RMurphy195 just like it did with the MK3.

I've altered my battery in Forscan so it thinks it's a 70ah not a 52ah and normally in a morning it reads 11.4v via the cig lighter with the gizmo plugged in ( I know it gives a lower reading by 0.6v) and reads 12.4v by the time I've driven 1.6 miles to work.

Since I altered it on Monday it's now risen to 11.9v first thing in morning and now reads 12.9v after my short trip to work so I'm hoping its slowly putting something back in. 

 

[RMurphy195]

16 hours ago, Wino said:

Mine works within half a mile even with cold temps @RMurphy195 just like it did with the MK3.

I've altered my battery in Forscan so it thinks it's a 70ah not a 52ah and normally in a morning it reads 11.4v via the cig lighter with the gizmo plugged in ( I know it gives a lower reading by 0.6v) and reads 12.4v by the time I've driven 1.6 miles to work.

Since I altered it on Monday it's now risen to 11.9v first thing in morning and now reads 12.9v after my short trip to work so I'm hoping its slowly putting something back in. 

 

I'd be interested in the Gizmo - is it a voltmeter, and does it show the charging voltage as well? 12.9 is higher than the voltage readings I get across the battery terminal (though having the battery connected to the car might give a lower reading) of 12.45 when the car's welcome lights have gone out (12.43 before) and 14.82 when the engine is idling.

[Wino]

4 hours ago, RMurphy195 said:

I'd be interested in the Gizmo - is it a voltmeter, and does it show the charging voltage as well? 12.9 is higher than the voltage readings I get across the battery terminal (though having the battery connected to the car might give a lower reading) of 12.45 when the car's welcome lights have gone out (12.43 before) and 14.82 when the engine is idling.

It just gives a rough idea of where it's at. 

On tickover its normally at 14.9v and occasionally drops down to 14.3v if we go a run but its very rarely under that. The lower the reading whilst its running the higher it will be when stood obviously.

Majority of the time it relates to key cycles though and doesn't show up immediately.

[RMurphy195]

Thanks Wino - Halfords special, or do you have a link to the supplier thanks

[unofix]

They can be very expensive, but if you want one here is the link:-

https://www.ebay.co.uk/itm/143362017907?hash=item21610aca73:g:gN8AAOSw8Ytdee5f

OR very expensive .....

https://www.ebay.co.uk/itm/264797885532?hash=item3da72f145c:g:i0cAAOSwWttfYscD

[RMurphy195]

5 hours ago, unofix said:

They can be very expensive, but if you want one here is the link:-

https://www.ebay.co.uk/itm/143362017907?hash=item21610aca73:g:gN8AAOSw8Ytdee5f

OR very expensive .....

https://www.ebay.co.uk/itm/264797885532?hash=item3da72f145c:g:i0cAAOSwWttfYscD

Hmmmm - at that price I'll maybe have to think again ...

[RMurphy195]

On 1/6/2022 at 5:18 PM, RMurphy195 said:

Have only just received my ELM327 so haven't connected up to Forscan yet but will read off (and hopefully store) these details once I'm confident with the kit. Supposed to be 70ah but you never know!

battery is 70ah, but I can't figure ot how to see what the setting is using Forscan! I can get the list of modules, and run a self-test on BdyCMD but can't see hope to get at the battery information. I'm using the Tunnelrat ELM which gives an "unsuitable" error message on Forscan.

Any set-by-step instructions anywhere - I haven't been able to find any on the Forscan forum thanks

[Wino]

59 minutes ago, RMurphy195 said:

Battery is 70ah, but I can't figure ot how to see what the setting is using Forscan! I can get the list of modules, and run a self-test on BdyCMD but can't see hope to get at the battery information. I'm using the Tunnelrat ELM which gives an "unsuitable" error message on Forscan.

Any set-by-step instructions anywhere - I haven't been able to find any on the Forscan forum thanks

Theres a drop down option at the bottom of the Forscan with options of APIM, BdyCM etc etc, select BdyCM wait for it to load and click in battery type and theres a list in there.

[RMurphy195]

Is that the config and programming page (the one just below the spanner in the attached piccy? I'm guessing I click on the BdyCM module then a list comes up in the name panel? I did try that - and right-clicking as well - but perhaps didn't wait long enough! Will try gain thanks

 

 

 

[Buxty]

1 minute ago, RMurphy195 said:

Is that the config and programming page (the one just below the spanner in the attached piccy? I'm guessing I click on the BdyCM module then a list comes up in the name panel? I did try that - and right-clicking as well - but perhaps didn't wait long enough! Will try gain thanks

 

 

 

Click BodyCM then hit the play button at the bottom, it’ll ask you if you have a switchable lead and ask you to flick it if needed then it’ll load the list of items. 

[archie2000]

Is this change to the battery type something that should be done in conjunction with changing the SOC to a higher setting?

Although I changed my SOC to 95% a few weeks ago, the Stop/start has stopped working again, and unlocking from any door is intermittent. This could of course be due to the low temperatures of late, but I was under the impression that raising the SOC would stop the dropping of features.

[RMurphy195]

1 hour ago, Buxty said:

Click BodyCM then hit the play button at the bottom, it’ll ask you if you have a switchable lead and ask you to flick it if needed then it’ll load the list of items. 

Ouch - comes up with "Sorry, you need an extended license tu run this function"!

[unofix]

1 hour ago, archie2000 said:

Is this change to the battery type something that should be done in conjunction with changing the SOC to a higher setting?

It probably should be done but to be honest although I was one of those many months ago that advocated that the SOC needed to be changed from 80% to 90 or 95%, I was not until a couple of weeks ago even aware of the battery size issue.

My SOC has been set at 95% for at least 6 months now and all seems to be OK, but I will be checking my battery size and will probably adjust it to the correct size.

Your problem with the door locks being intermittent could still be a situation of the battery SOC falling below 70% due to perhaps many short journeys and the use of heated screens, heated seats, headlights etc. With a decent run the battery should recover back to your set SOC of 95%.

The issue of S/S not working although it could also be related to a low SOC, there are many other things which will inhibit its operation such as very low temperatures, the use of heated screens etc and even the settings of the climate controls. The Goldie Locks list of what needs to be 'just right' for S/S to operate if very long. 

[archie2000]

23 minutes ago, unofix said:

It probably should be done but to be honest although I was one of those many months ago that advocated that the SOC needed to be changed from 80% to 90 or 95%, I was not until a couple of weeks ago even aware of the battery size issue.

My SOC has been set at 95% for at least 6 months now and all seems to be OK, but I will be checking my battery size and will probably adjust it to the correct size.

Your problem with the door locks being intermittent could still be a situation of the battery SOC falling below 70% due to perhaps many short journeys and the use of heated screens, heated seats, headlights etc. With a decent run the battery should recover back to your set SOC of 95%.

The issue of S/S not working although it could also be related to a low SOC, there are many other things which will inhibit its operation such as very low temperatures, the use of heated screens etc and even the settings of the climate controls. The Goldie Locks list of what needs to be 'just right' for S/S to operate if very long. 

I rarely, if ever use the heated seats and heated steering wheel to be honest. Short journeys could be an issue I guess (whatever is classed as a short journey). I've probably only used the heated windscreen maybe once or twice, which tells you I don't get out much just lately in the car anyway.

I do fully charge the battery up at least once a week though.

I'll amend the battery size and see if that makes a difference. 

[unofix]

6 minutes ago, archie2000 said:

I do fully charge the battery up at least once a week though.

Your battery should be "fighting fit !"

Just checking that when you charge it on the car that you are connecting the negative lead on the charger to the main chassis earth point and not to the battery terminal.

Short journeys are typically anything less than 7 miles.

Next time you fully charge your battery it may be worth resetting the BMS and see how things go from there.

[unofix]

4 hours ago, RMurphy195 said:

I'm using the Tunnelrat ELM which gives an "unsuitable" error message on Forscan

This is a very recent problem  that only happens with the very latest version of FORScan. Don't worry about it, or if it bothers you use an older version of FORScan and the message will go away.

You might find this video of help:-

 

[Wino]

I may as well add that regarding the doors locks.

All mine have worked on all four doors since I've had the car even when the SOC has been at 50%.

[archie2000]

2 hours ago, unofix said:

Your battery should be "fighting fit !"

Just checking that when you charge it on the car that you are connecting the negative lead on the charger to the main chassis earth point and not to the battery terminal.

Short journeys are typically anything less than 7 miles.

Next time you fully charge your battery it may be worth resetting the BMS and see how things go from there.

I connect the negative clip to where the earth lead from the battery connects to the chassis.

Due to working from home, I typically do numerous journeys that are less than 7 miles rather than longer business trips. For example, visiting family, shopping, etc.

It's currently on charge now, so I'll do a BMS reset later, after I have changed the battery type.

[Buxty]

3 hours ago, RMurphy195 said:

Ouch - comes up with "Sorry, you need an extended license tu run this function"!

You can get two months or so for free on the ForScan site, otherwise it’s less than a tenner for a year. Considering how good the program is, I think it’s worth it 

[archie2000]

I've changed my battery settings to the correct Varta 70 amp battery. Where do I go in the Forscan settings to reset the BMS?  I did find a battery Monitoring System in the HVAC module, but it was set to disabled?? I didn't want to enable it in case it is the wrong one.

I've tried the different manual methods of resetting the BMS and none of them work for me.

[Tizer]

2 hours ago, archie2000 said:

I've changed my battery settings to the correct Varta 70 amp battery. Where do I go in the Forscan settings to reset the BMS?  I did find a Battery Monitoring System in the HVAC module, but it was set to disabled?? I didn't want to enable it in case it is the wrong one.

I've tried the different manual methods of resetting the BMS and none of them work for me.

You'll find it under service Procedures.

[unofix]

4 hours ago, archie2000 said:

I've tried the different manual methods of resetting the BMS and none of them work for me

This method should work, if not then maybe there is a problem with the BMS

 

[Ivo Fidalgo]

@unofix - Been reading the topic from the beginning and i've a question (dumb one.. xD) : 
 

-> does this issue happen to the mk3 (FL) ? does BCM recognizes the battery with a smaller capacity and it is set to a small SOC as well ?

 

thanks in advance

[unofix]

Hello Ivo,

Just want to make sure we are all talking about the same thing.

BCM = Body Control Module ... Looks after things like lights, wipers, screenwash, locking, and much more.

BMS = battery Monitor System ... checks on the amount of current going in to, or, out of the battery.

So as far as I know the issue of the SOC being set to 80% (at least in the UK) does also apply to the Mk3. As regards to what size of battery is set, I don't know for the Mk3. We have established on the Focus Mk4 that adjusting the SOC does not alter the size of the battery set. So it seems that this is not something that is automatically calculated, but is in fact a parameter that has to be manually changed, and is independent to the setting of the SOC.