Battery equalisation

Adi6phil

Adi6phil

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I have had my zs now for nearly 3 months and have fully 100% charged it with my Chargemaster 7kw charger but never had chance to fully equalize the battery. Yesterday i was determined to see it through til the MG badge charge light went out .to my suprise it took more than 6 hours after the battery showed 100% to fully equalise .in total the car was on charge for 13 hours . It says in the manual that a slow charge is needed if you rapid charge too often . I will rarely use a rapid charger as i will mostly charge at home but i thought it was worth a mention.
 
Yes you should look to, if you can, equalise once per month and if you do this it shouldn’t extend your normal charging too long, but it makes sense to level out the battery power.
Mine has never taken that long, it may have been about an hour tops...!
Has you estimated range increased following this charge??
 
Range has not altered but the few miles i have driven today have been accurate. Lately the range has been dropping quicker than the mileage driven .
 
Adi6phil said:
Range has not altered but the few miles i have driven today have been accurate. Lately the range has been dropping quicker than the mileage driven .
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That’s the cold temperatures I’m afraid...
 
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Maybe it took so long as it was the the first time ever from new and its been almost 3 months .i will see how it goes when i next charge it in a few days
 
Adi6phil said:
I have had my zs now for nearly 3 months and have fully 100% charged it with my Chargemaster 7kw charger but never had chance to fully equalize the battery. Yesterday i was determined to see it through til the MG badge charge light went out .to my suprise it took more than 6 hours after the battery showed 100% to fully equalise .in total the car was on charge for 13 hours . It says in the manual that a slow charge is needed if you rapid charge too often . I will rarely use a rapid charger as i will mostly charge at home but i thought it was worth a mention.
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Did you monitor how much electricity it used? I wonder if it uses more to equalise than to just charge to full?
 
Cocijo said:
Did you monitor how much electricity it used? I wonder if it uses more to equalise than to just charge to full?
Click to expand...

Here is a screen shot of a recent charge and equalisation on my ZS EV(My cars BMS software was updated on the 20th October, I'm not experiencing the range issues others have with the latest BMS software, but I do have the circa 5 hours equalisation Miles stated on another thread).

Whilst the scale on the graph isn't great, the equalisation took approximately 4h30mins @ 300W = 1.35kWh. The total charge on that session was 30.1kWh, equalisation accounted for ~4.5%

MilesperkWh said:
Hi all,
I've had confirmation today that MG has spotted a bug in the BMS code from the recent August/October updates.
It looks like the August update caused cell balancing issues when full (so the end balance took 5hours or so). They tried to rectify this in the October update, but then found that this caused cell balancing issues when SOC was lower. This has caused range issues, as the car isn't able to use the full pack capacity.
By the end of next week, there will be a new BMS update released to the dealer network, which will be able to fix the affected vehicles.
Click to expand...


screenshot_20210106-182952-png.1050
 
Cocijo said:
Did you monitor how much electricity it used? I wonder if it uses more to equalise than to just charge to ful
Click to expand...

Tango130 said:
Here is a screen shot of a recent charge and equalisation on my ZS EV(My cars BMS software was updated on the 20th October, I'm not experiencing the range issues others have with the latest BMS software, but I do have the circa 5 hours equalisation Miles stated on another thread).

Whilst the scale on the graph isn't great, the equalisation took approximately 4h30mins @ 300W = 1.35kWh. The total charge on that session was 30.1kWh, equalisation accounted for ~4.5%




screenshot_20210106-182952-png.1050
Click to expand...
That sounds interesting as i purchased my zs in 17th October 2020 ,i am waiting to see how long it takes to equalise next time i FULLY charge it
 
Cocijo said:
Did you monitor how much electricity it used? I wonder if it uses more to equalise than to just charge to full?
Click to expand...
It uses less electricity to equalise .i the more charged the batteries are the lower the rate of charge .
 
Adi6phil said:
It uses less electricity to equalise .i the more charged the batteries are the lower the rate of charge .
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Yes. That makes sense. I guess most owners who just plug in and leave overnight/10hrs+ get equalization every time they charge?
 
Adi6phil said:
That sounds interesting as i purchased my zs in 17th October 2020 ,i am waiting to see how long it takes to equalise next time i FULLY charge it
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I should add that my car registered 454v and GOM of ~130mile range after this charge.

I drive everywhere in N and uses heating/heated seats most of the time at the moment. For the last 3 charges I've managed to get 120-130 miles which considering the regular de-icing, temperature and conditions I'm happy with.
 
Tango130 said:
I should add that my car registered 454v and GOM of ~130mile range after this charge.

I drive everywhere in N and uses heating/heated seats most of the time at the moment. For the last 3 charges I've managed to get 120-130 miles which considering the regular de-icing, temperature and conditions I'm happy with.
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What you just wrote is the same as me .sod economy ,i like to be comfortable .when mine is fully charged in winter it shows 135-140 in N mode with all the warm stuff turned on full . But i probably get same as you 120-130 .im okay with that
 
cazarol1501 said:
Hi, sorry about this dim question, what does battery equalisation actually mean and how would I do it 🤣
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Not at all. The high voltage battery pack is made up of many smaller batteries joined together. Some of these batteries from time To time get out of sync with the others. This is when they need to get equalised so that the pack can perform at it’s best. On the ZS you just fully charge on a fast or granny charger (must be AC) and leave the battery management system to do it’s thing. Once equalised the MG badge will go out. 🙂
 
Does anyone know if you can see on the app if this being done or complete?

I ask as I will not have a home charger so will be using street fast chargers (7 kW) and would be good to be able to remotely check.
 
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The old ZS port used to flash during the different charge stages.
I can only tell on my MG5 by monitoring my IHD as during a battery balance the wattage is 300W -500W.
How long can you leave the car connected to a street EVSE!
 
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