Equalisation charge

[MarkLynn]

What sort of time does the equalisation part take after reaching 100%?

 

[Jomarkh]

Hi, if you have used a lot of rapid charge unit could be over an hour, you can see on your IHD as the power draw drops to about 300-500w while the batteries balance.

 

[MarkLynn]

Just taken 2.5hours but I was using the granny charger so I guess that's about right. Car said finished lots of times before I just did not wait for the uncharging, so this may be the first full balancing I've done in 3 months. I would not of known all this apart from this site, thanks to everyone who contributes.

 

[Alb]

Have a look at this:

Good Practice for Battery Life and Home Charging

Hi all, I just got my home charger installed - a PodPoint. I'm typically going to do very few miles -just short trips round town - with the off longish trip thrown in. My limited research would suggest that good practice would be: 1. not to continually recharge the battery - I'm thinking I'll...

www.mgevs.com

 

[Lovemyev]

Just taken 2.5hours but I was using the granny charger so I guess that's about right.

Conducting a balance from either a wall box or a Granny, is likely to take about the same time.
Both devices are capable of providing the same level of charge, when carrying out this process.
Generally they are only pulling around 500 Watts to balance.
When the balance is about to complete, the demand will reduce down to 175 Watts and then finish very soon after.
It's a bit of a trickle charge in EV terms .
This can be seen, if you have a home energy monitor and can be bothered to watch it .
Ask me how I know ! - ( Sad Bugger ).

 

[MarkLynn]

Your not the only person lol, I watched mine like that, it's a shame mg don't have an app so we can check it on that as well.

 

[Delboy102000]

My balancing is constantly taking about four hours on my Pod Point 7kw home charger, despite not having used commercial cc’s chargers at all for months. Does this indicate a problem?

 

[Ozzie1989]

When you say constantly, how often are you doing it?

Also just noticed you have a ZS, this is the MG5 forum so you may well be suffering with a BMS issue on the ZS. Best to check the ZS forum

 

[Delboy102000]

When you say constantly, how often are you doing it?

Also just noticed you have a ZS, this is the MG5 forum so you may well be suffering with a BMS issue on the ZS. Best to check the ZS forum

Thanks for pointing out. However balancing will be the same issue on either vehicle. My Zs has the latest BMS update installed. I equalise every time I recharge. To do this on my Pod Point you just let it run until it finishes when it disconnects. This is usually in the region of four hours after full recharge level has be reached. Over the four hour period charger consumes about 1.5 kw after the 100% has been reached

 

[Alb]

Over the four hour period charger consumes about 1.5 kw after the 100% has been reached

That's very high.
It equates to 6kWh over the balancing period you mention.
My car was only consuming about 300W during balance.

 

[pjmuk]

My MG5 SR, which I always charge to 100% and equalise when I charge at home, sometimes takes 10 minutes, and sometimes 4 to 5 hours to equalise. 95% plus of my charging is done at home on my Wallbox Pulsar Plus. I've not fathomed why it sometimes takes so long but it only uses about 300w/ hour so about 1.2kWh in total, which is minimal in the scale of things.

 

[Kithmo]

That's very high.
It equates to 6kWh over the balancing period you mention.
My car was only consuming about 300W during balance.

I assumed he meant 1.5kWh total .375kWh per hour.
My ZS has recently started only taking half an hour to equalise on my Pod Point, even though my cells are out by 40mV.
If I unlock and re-lock the car it then carries on balancing for a further 1 to 1.5 hours and the cells are still 40mV out.
I don't think I'll bother with the lock and re-lock now as it only adds to the electric bill, nothing to the GOM or the fully charged battery voltage of 456V.

 

[Delboy102000]

Sorry what do you mean about 40mv out. My car recharges to 449/450 since the BMS patch. Before that it was 456.

 

[Jomarkh]

I assumed he meant 1.5kWh total .375kWh per hour.
My ZS has recently started only taking half an hour to equalise on my Pod Point, even though my cells are out by 40mV.
If I unlock and re-lock the car it then carries on balancing for a further 1 to 1.5 hours and the cells are still 40mV out.
I don't think I'll bother with the lock and re-lock now as it only adds to the electric bill, nothing to the GOM or the fully charged battery voltage of 425V.

425V you need to take it back to the dealer

 

[Kithmo]

425V you need to take it back to the dealer

Typo now corrected to 456V

 

[Kithmo]

Sorry what do you mean about 40mv out. My car recharges to 449/450 since the BMS patch. Before that it was 456.

Using the ZS EV app and an OBD2 bluetooth adaptor to read the maximum and minimum cell (module) voltages.

 

[BarryH]

Equalisation if done regularly will only take about 30 mins to level up the charge across the cells. It will take longer if done less frequently. However, there is a limit to how much the pack can be equalised in one hit. The Equalisation will stop when that mV is reached or 3 hours (don't quote me on that it's just from memory) even if the pack is still not optimised its Equalisation. Equalisation also takes place during discharge when driving from a 100% Full state of charge (SOC) down to 95%-97% (from memory). There was a lot of discussions early last year on this topic on the ZS Forums and Podcast after the bad BMS update when those ZS cars that had the bad update became very seriously un-Equalised and it seriously affected their range. It took a couple of months of nightly Equalisation charges to rectify after the BMS update had been corrected.

 

[Lovemyev]

I think it’s an accepted practice, that the ZS EV will generally take a shorter time to perform a balance cycle, when you are running on the factory 456 volt software.
Having run on the factory software for 12 months, then switched over to the Jan 21 BMS for further 12 months, I can comfortably say that the balance time IS definitely longer on the new BMS update, than the original factory software.
This comes as no surprise really, because part of the new BMS update, was to increase the size of the buffer at the upper end of the HV pack.
When on the previous factory software, I have witnessed balance times of anything from as little as 30 minutes, to around 1 hour.
After the new BMS these times have taken anything from around 2 hours and up to 3 hours after reaped balance cycles.
The first charge and balance I performed after getting the car back, was like pulling teeth !.
The balance was still going at it after about 8 hours !.
It will “time out” after about 10 hours I think Miles once said.
It was acting really strange at first, when plugging in from a low SOC - the car would sometimes only pull 3.7 kw’s from our wall box, and went on for hours ?.
It did this intermittently for about a week, until it started regularly started allowing the full 7.0 kw’s to the car.
Over this time, I had spoken the Tech Team at Rolec and asked if it could be wall box or lead at fault, but apparently not on our 5 year dumb wall box !.
This where my obsession developed for monitoring the charge / balance behaviour on our home energy meter.
It was invaluable piece of equipment to record what and when was going on at the time.

 

[Delboy102000]

Before updating BMS my pack used to charge to 456 volts. What was wrong with that, it now peaks at 449/450. Since the new patch was installed. Surely this is normal. My query was regarding approx 4 hours to equalise.

 

[Lovemyev]

One feature of the new Jan 2021 BMS was too reduce the pack voltage down from 255 - 256 volts down to 449 - 450 volts.
This is indeed completely normal !.
Owners are now reporting longer balance times as a result of the update.
This COULD be because of increased space at the top of the pack.
It MAYBE the reason why balancing now takes longer than it did before.
In the first 12 months of ownership, I would only charge to 100% IF I needed to make a longer trip.
In most cases, I would only charge to around 80% in attempt to be kind to my pack.
The pack could well have been out of balance prior to the update ???.
Charging every time to 100% after the update, felt a little like chasing a magical unicorn to be honest.
Trying to hit the magical 450 volts and the suggested 163 miles of range should be expected after the update.
These are “Headline” ideal base line figures.
After 12 months of receiving the update, I have now found that the BMS has had time to evaluate the actual SOH of the pack, and is now regularly reporting a more true and genuine figure of the predicted mileage reported on the GOM.
It has taken a few months to analyse and account for any battery degradation in the pack.
When the BMS is installed it wipes out any historical data and is given a base line to work from.
Then from this baseline, it will start to figure out what is going on with the pack.
If you car received the BMS update and you are a low usage case, it is likely to learn what is going on fairly quickly.
If you are a higher usage case, then it is going to take a little longer for results to be more consistent.
My car is over two years old and has covered 18,000 miles.
It NOW consistently reports 449 volts and an predicted range of 145 miles after a full charge and balance.
This indicates a battery SOC of around 94ish percent .