Trickle Charging issues on MG ZS EV

[martin181187]

Hi I have a MG ZS EV exclusive 21 plate. I’m just wondering if anyone may be able to help as not had much luck with dealer or with Project EV. My question is does anyone else have an issue when charging there car at home on a 7kwh after its finished its normal full charge my car starts to trickle charge at 1kW. I never used to have this issue; always disconnected once charged and turned off now since September October time this hasn’t been the case it keeps trickle charging. I had the car in garage they say they can’t find an issue and say to use a 3 pin plug charge and charge car for 24hr done that still it trickle charges on my normal Project EV charger I had installed so then Project EV replaced my old box with a brand new one and still the issue of the trickle charging is happening. So what is causing this problem; does anyone else have this issue and if so how can anything be resolved/done to fix this? thanks

 

[Alb]

It's just doing a balance charge, perfectly normal.
If you do a search on the subject you will find a multitude of threads explaining what it is

 

[martin181187]

It's just doing a balance charge, perfectly normal.
If you do a search on the subject you will find a multitude of threads explaining what it is

Hi ya yeah it’s never done this before had the car 3 years and always charged fine on my 7kW Project EV charger and used to disconnect from charger and stop at 100% but since September October time it doesn’t it just constantly trickle charges now. Dealership said to do it on my 3pin wall plug charger which should stop this happening which I’m trying now but it don’t say when the car is charged how will I know when this is complete will the light turn off on the charger or does the light turn off on the charger in the picture or something? Thanks for your help and advice.

 

[hmadsen]

When it stops charging and does the trickle charge, does it ever stop.

Should take an hour or maybe 2, but if it continues for many hours with this, i would imagine it could possibly indicate that one or more of the cells never reach Equilibrium.

Trickle charge is done where it can charge individual cells so they get to the same voltage.

If a cell or some cells are "bad" they might never be able to reach the voltage of the other cells.

Just a guess.

But i would say, it would be strange if it has never done the trickle charge before if you regularly charged to 100%

I would imagine every EV does this, i know that my Tesla certainly does this as well. Sometimes when i plug it in, it will say that it will finish in X hours, but if i calculate the time it should take to reach 100% it might be 1 hour less, and then when charging at 11kW, it will first drop to 5kW when very near 100% and then all the way down to a few kW, when reaching 99% and then be at that level for an hour. If i unplug while it draws very little, the SoC meter will show 100% so the battery is fully charged, but not fully balanced.

 

[martin181187]

When it stops charging and does the trickle charge, does it ever stop.

Should take an hour or maybe 2, but if it continues for many hours with this, i would imagine it could possibly indicate that one or more of the cells never reach Equilibrium.

Trickle charge is done where it can charge individual cells so they get to the same voltage.

If a cell or some cells are "bad" they might never be able to reach the voltage of the other cells.

Just a guess.

But i would say, it would be strange if it has never done the trickle charge before if you regularly charged to 100%

I would imagine every EV does this, i know that my Tesla certainly does this as well. Sometimes when i plug it in, it will say that it will finish in X hours, but if i calculate the time it should take to reach 100% it might be 1 hour less, and then when charging at 11KW, it will first drop to 5KW when very near 100% and then all the way down to a few KW, when reaching 99% and then be at that level for an hour. If i unplug while it draws very little, the SoC meter will show 100% so the battery is fully charged, but not fully balanced.

Hey ya thanks yeah when I charged it the other day it was still saying charging the next day I charged over night for cheaper tariffs but car said 100% when I checked the dash in the morning yet it was still saying charging and found out it was trickle charging at 1kwh even 3 hours later it said this on my app so it don’t seem to turn off at all like it used to. So not sure what’s going on as never had this before

 

[fred12345]

how will I know when this is complete will the light turn off on the charger or does the light turn off on the charger in the picture or something?Thanks for ur help and advice

Just leave it plugged in for as long as you can, even for extra 12 hours after the car says 100%, to balance the battery. The blue/green light should turn off after fully charged and balanced. Mine also trickle charges for a while after reaching 100%

 

[martin181187]

Just leave it plugged in for as long as you can, even for extra 12 hours after the car says 100%, to balance the battery. The blue/green light should turn off after fully charged and balanced. Mine also trickle charges for a while after reaching 100%

Ok that’s great thank u ill leave it alone and just let it do its thing I’ve had it on charge now since about 2pm today

 

[fred12345]

I had the opportunity to check something, when my MG showed 100%, I plugged it in and it continued charging and balancing for another 4 hours at around 1.7kW adding 7.8kW to the supposedly full battery...
Yours might be doing the same so unless you have some other issues with the car, I wouldn't worry much ...

 

[Gadget Geek]

Also, it depends on how balanced the cells are to start with. A small imbalance will be corrected in an hour or two, whereas a big descrepency might take several hours to correct.

 

[Spinynorman]

I have a 20 plate exclusive (Gen 1) and use a Zappi 2 charger. My charge is usually a few hours at 7KW followed by a drop to 0.3KW for at least 3-4 hours. After that my charger says it’s complete and stops the charge. You should be able to tell the difference with the light astound the MG badge - it’s solid white for full charge then switches to intermittent pattern - on-off-on etc) when running the equalisation charge. The granny charger does the same though at a much lower wattage hence the longer time it takes. If you use rapid charging at public sites, it’s recommended you do a granny charge at least once a month, to keep the cells in balance.

 

[Piperman]

Hi I have a mg zs Ev exclusive 21plate. I’m just wondering if anyone maybe able to help as not had much luck with dealer or with product Ev. My question is does anyone else have an issue when charging there car at home on a 7kwh after its finished its normal full charge my car starts to trickle charge at 1kwh. I never used to have this issue always disconnect once charged and turned off now since September October time this hasn’t been the case it keeps trickle charging I had the car in garage they say they can’t find an issue and say to use a 3 pin plug charge and charge car for 24hr done that still it trickle charges on my normal project Ev charge I had installed so then project Ev replace my old box with a brand new one and still the issue of the trickle charging is happening. So what is causing this problem does anyone else have this issue and if so how can this be resolved/done to fix this thanks

Set the charging time to what time you want your car to charge. On timed charging. Then once a month set the time to finish a couple of hrs longer to allow your battery to balance.

Ps. You don't want to be charging to 100% all the time. They recommend to charge for 20% to 80% unless you're planning on going on a longer run.

 

[Stoob]

Similar issue. However, my 2020 Exclusive used to charge to 100% then stop. (I have a QUBEV smart charger). The other day I tried the granny charger out. It didn’t work. Took it to my garage yesterday. They couldn’t fix it. AND the tech told me it wasn’t charging on their charger either. Worried, I brought it home and plugged it in. For the first time, it charged fully then went onto about 1 kW. I stopped that after 3 hours, at midnight. Curious, I restarted the charge, which continued for a less than an hour before ending.
This morning, it reported a range of 173 miles. Never been above 168 before. I’m assuming that the tech reset the ECU so that it now allows trickle charging, where it did not before. Perhaps while trying to get the granny charger to work? Was a bit worried but, reading this thread, I now suppose they may have reset the equalisation facility. Might this help extend the battery life?
Granny charger still doesn’t work; taking it back to the garage next week so they can talk to MG about it.

 

[Coulomb]

I now suppose they may have reset the equalisation facility.

I suppose that they might have reset the BMS somehow, either by updating firmware, by some special command, or merely by disconnecting the 12 V battery for 10 minutes.

I'm wondering if your EVCC (EV Communications Controller) is intermittent; there was a batch of dodgy ones used around the COVID era.

Or perhaps your faulty granny "charger" is upsetting the EVCC or other ECUs.

I hope you get it sorted soon.