Battery SOH

[Wolfy]

Hi, firstly I must congratulate you for this forum, really is so much information.
I purchased my exclusive ZS in March,and it had done 50 miles. The car has behaved with no problems or rattles and I love it to bits. However I have noticed of late that when charging on my granny which I have always used iam only getting 437kw and that's after balancing which takes about 2 hours. It is running at between 4.2/4.5.
My question is could the info be right and would I be better if I checked with a OBD2
Also where is the socket to plug in?
Many thanks in advance

 

[Kithmo]

What SOC are you starting the charge at ?

 

[Wolfy]

About 412

 

[Kithmo]

About 412

That figure doesn't mean a thing to me, what percentage on the screen when you plug it in or how many bars left on the HV battery meter on the right hand dial when it's switched on ?

 

[Wolfy]

Usually when I plug in it shows 70/75% and it has used 2 bars on the meter. The lowest I have let it run would be 50%and that would 4 bars used.

 

[Wolfy]

I have just completed a charge and has gone on to balance. It is showing 169mls.This is slightly higher than the last charge which was163 mls but when started the car it dropped to 147mls?

 

[macd2401]

Hi, firstly I must congratulate you for this forum, really is so much information.
I purchased my exclusive ZS in March,and it had done 50 miles. The car has behaved with no problems or rattles and I love it to bits. However I have noticed of late that when charging on my granny which I have always used iam only getting 437kw and that's after balancing which takes about 2 hours. It is running at between 4.2/4.5.
My question is could the info be right and would I be better if I checked with a OBD2
Also where is the socket to plug in?
Many thanks in advance

When you say you're only getting 437kW, what do you mean? Same with the running between 4.2/4.5?

Do you mean 437V when it's fully charged?

The OBD socket is behind the bonnet release.

 

[Kithmo]

Usually when I plug in it shows 70/75% and it has used 2 bars on the meter. The lowest I have let it run would be 50%and that would 4 bars used.

I assumed you meant 437W (0.437kW) charge rate, the charge rate slows down when it's getting near full.

 

[Wolfy]

Thanks for the replies, yes 437 v
Will put a OBD2 on and see what battery reading I get.... Cheers

 

[macd2401]

Thanks for the replies, yes 437 v
Will put a OBD2 on and see what battery reading I get.... Cheers

OK, if the maximum voltage you're getting once it's fully charged is only 437V, you have a potential problem. Definitely get an obd reader (there are a few threads on here with discussions about which ones to get).

Be aware that some cars were updated prior to sale with an update to their Battery Management Software, but there was a small batch that were given an upgrade that caused problems. The symptoms of this include a drop in range, and a continuing drop in max charge voltage, regardless of how long it's plugged in for. At first glance, it sounds like you may be having this issue.

First off, have a search on here for "project obd 2" for the best Bluetooth obd reader to get (they're not that expensive, but be aware some of the dirt cheap ones may not work). Once you've got the obd, you should find the thread also has quite a lot of info regarding how to get data off the car to check if you've been affected by the dodgy update.

In any event, if it is the dodgy update, it's fixable, and you'll need to contact the dealer to let them know youre having issues. MG do know about it, but they're waiting till the users find the issue, rather than go out and contact them ?‍

 

[Lovemyev]

Usually when I plug in it shows 70/75% and it has used 2 bars on the meter. The lowest I have let it run would be 50%and that would 4 bars used.

Not judging, but why do you feel compelled to keep charging the HV battery from 75% back up to 100% every time you use the car ?.
It would appear that your usage case is fairly small and are making small trips.
Do you get range anxiety or are you just plugging it in as a force of habit ?.
This type of practice CAN be seen as unkind to your pack.
I know some owners like to keep their packs at 100% regardless to the mileage they are likely to cover.
But I think we all agree ( or not ) that charging the pack to 100% and then leaving the car to sit unused is not a great situation for longer term battery health.
Constantly charging the battery back up to 100% after each and every small trip is almost the same thing ?.
There is an extensive thread on the forum about what you should expect to see as a voltage and predicted range after a full charge and balance.
The information has been compiled after a LOT of input from other EV owners and is very informative.
This has been the result of different ZS EV owners running in different BMS software packages and some cars have badly affected HV packs as a result of “Buggy” software installs.
This is totally reversible after a new software update and some time spent rebalancing the pack.
Not ALL cars are affected it should be said.

 

[Wolfy]

Thanks for the Info, I have just completed a charge from 70% and it is still 437v but giving a range of150 miles.
I will let it run down now and see what it
Does on the next charge and check with A OBD2.
The car is due for 1st service November
So will probably book a little earlier if the problems continue.
Again many thanks for your help,
Les(wolfy)

 

[Lovemyev]

No 100% certain as you testing is still work in progress.
But your low voltage reading MAY suggest you have been affected by the "Buggie" software.

 

[JodyS21]

Hmm, first service due in November gives it away.... if the car was from around Nov 2020 then that’s the timeframe for the dodgy BMS software.
Given the above and that you seem to be saying that after a full charge your voltage is showing as 437v ish (should be 450-455ish), I’d say it is 99.9% certain you have the dodgy BMS and should take it back to a dealer to fix ASAP (it’ll only get worse & take longer to get back to full health).

All dealers have been given list of cars with the dodgy BMS & should have contacted their customers that need it fixing.....

 

[Lovemyev]

Hmm, first service due in November gives it away.... if the car was from around Nov 2020 then that’s the timeframe for the dodgy BMS software.
Given the above and that you seem to be saying that after a full charge your voltage is showing as 437v ish (should be 450-455ish), I’d say it is 99.9% certain you have the dodgy BMS and should take it back to a dealer to fix ASAP (it’ll only get worse & take longer to get back to full health).

All dealers have been given list of cars with the dodgy BMS & should have contacted their customers that need it fixing.....

I have similar feelings that the "Buggy" software is at work here !.

 

[Wolfy]

Hi JodyS21
Thanks for the info. The Car was registered November, but I purchased it
Mid March 2021 with 50 miles on the clock from a reputable dealer who said it had the latest updates and I must admit it
runs really well and I am really happy with it. I only charge on my granny charger!!
Kind regards Wolfy

 

[Gomev]

Hi JodyS21
Thanks for the info. The Car was registered November, but I purchased it
Mid March 2021 with 50 miles on the clock from a reputable dealer who said it had the latest updates and I must admit it
runs really well and I am really happy with it. I only charge on my granny charger!!
Kind regards Wolfy

Just because the dealer says it had the latest updates doesn't necessarily make it so.
Even with the buggy BMS it will run well but the range will reduce, and the longer you leave it the longer it will take to get it back to 100%.
It may be worth checking here, but this may not cover the BMS problem as it wasn't a safety issue.

Recall Checker

We continually check vehicles throughout their lifecycle, and beyond, for safety and integrity. Should a safety issue arise, then once we notify the DVSA, we...

mg.co.uk

 

[Wolfy]

Hi JodyS21, Thanks for the info, I have done the tracker and it says no!

 

[JodyS21]

Just because the dealer says it had the latest updates doesn't necessarily make it so.
Even with the buggy BMS it will run well but the range will reduce, and the longer you leave it the longer it will take to get it back to 100%.
It may be worth checking here, but this may not cover the BMS problem as it wasn't a safety issue.

Recall Checker

We continually check vehicles throughout their lifecycle, and beyond, for safety and integrity. Should a safety issue arise, then once we notify the DVSA, we...

mg.co.uk

I’ve never seen this recall checker link before. I think you’re most likely right saying it probably doesn’t cover the BMS problem as it’s not a safety issue/real recall.

 

[JodyS21]

Hi JodyS21
Thanks for the info. The Car was registered November, but I purchased it
Mid March 2021 with 50 miles on the clock from a reputable dealer who said it had the latest updates and I must admit it
runs really well and I am really happy with it. I only charge on my granny charger!!
Kind regards Wolfy

Unless the dealer is Miles from Chorley I seriously wouldn’t trust a word they say regarding what updates are supposedly on it.

Just rereading your posts, on 2 occasions you’ve fully AC charged and have a voltage showing of 437v. You therefore 99.99% have the dodgy BMS version and need it updating/fixing ASAP. Don’t leave it until your November service, it’ll be even worse by then & take even longer to recover.

Read the very detailed info regarding this on the forum, it’s all there.
In summary, you’ve lost 18v (455-437) that’s a reasonable amount battery capacity lost.
After a full charge & balance, start car without pressing brake pedal (HV battery won’t be connected) & under no load (AC etc), Reset both trips. In Normal(3) mode the GOM range should normally show 163 miles - you’ll have less.

I can’t remember exactly now, but you’re looking at 10hours balancing to recover each 1volt you’ve lost - 18v = 180hours. You don’t want to let it get worse.

oh, you should get offered a free service for the inconvenience from MG