Battery Balance issues

[RF 10 Zen]

New to posting, so please excuse any errors....
BACKGROUND
I have a 2020 mg5 ev exclusive with 14000 miles recorded. It is never rapid charged and is always fast charged to 80% only and it's never allowed to drop below 20%. it's used daily, around 60 miles and a couple of longer trips most weekends of around 140 miles. I undertake a battery balance once each month.
PROBLEM.
Until recently, each battery balance has shown 405v upon completion which, I understand, indicates a fully balanced battery? The most recent balance charge shows only 404v. I have repeated the balance charge 3 times over the last 4 days, on one occasion leaving the car plugged in for a full 24 hours; end result 404v. The "guessometer" in the car shows a range of 220 miles after charging and on level 3 regeneration, which is what I normally see. Do I need to take any action, or is this normal battery degradation?
Any thoughts/comments would be appreciated.

p.s. the car is fully serviced, the next being due in August.

 

[johnb80]

I would suggest you've nothing to worry about. The electronics measuring the voltage may drift a little, the voltage from the cells may change slightly with temperature, 1v difference in 400 is a very small deviation.

 

[Fokmg]

I would agree there appears to be nothing to worry about. It looks to be in tip top condition.
Like you generally use the 80 20 rulef or charge and discharge and always make sure that I do a balance charge each month. My MG 5 has been fed exclusively from my Zappi at 7.1KW so no fast charger risk.
When you go for your service in August you should ask for a print out of the battery stats. The variation you have seen is within measurement errors and I suspect the recent high temperatures may have changed the reading by 1v

 

[5teep]

As John says, don't fret about it. My own car is charged to 100% every night, rapid charged often and I've not noticed any degredation of performance in 55k miles. Just drive it and enjoy it.

 

[johnb80]

In reality it's probably less than 1v difference, the system will round up / down fractions of a volt, in theory it could have been 404.6v in the past and now its 404.4v just 0.2v difference.

 

[Alb]

You are worrying unduly.
Have you checked the SOH figure?

 

[RF 10 Zen]

I would suggest you've nothing to worry about. The electronics measuring the voltage may drift a little, the voltage from the cells may change slightly with temperature, 1v difference in 400 is a very small deviation.

Thank you for your prompt reply.

 

[RF 10 Zen]

You are worrying unduly.
Have you checked the SOH figure?

Hi, I wasn't aware that there is a facility for checking battery SOH on an MG5; how would I proceed?

 

[Alb]

Have a look at this thread:

MG5 SOH

Just had my 2nd service today after 26K miles. Allegedly my SOH is 100%... Half of me is thinking 'fantastic', the other half is thinking - have they actually checked... Can anyone confirm a OBD2 dongle and android software i can use to check myself? Thanks.

www.mgevs.com

 

[RF 10 Zen]

Thank you

 

[Jomarkh]

Is it taking longer than before to do a battery balance?
220 showing on the GOM is great for an SR as mine shows the normal 214 each time I reset the trip counters after a balance.

 

[RF 10 Zen]

Is it taking longer than before to do a battery balance?
220 showing on the GOM is great for an SR as mine shows the normal 214 each time I reset the trip counters after a balance.

Hi, after reaching 100% charge, battery balance has normally taken between 3 and 10 hours (can tell when it's finished via the smart meter consumption figures. All previous balances have shown 405v on completion.

 

[Jomarkh]

When I have monitored a balance I think it took about 20 minutes and I use a Zappi daily and monthly balance, at the last service, 33k milage, SOH on the form was 100%