44.5 kWh battery becomes 29.1kWh battery

sbwithers

sbwithers

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Opotiki, New Zealand
I've had my MG ZS EV for about 8 weeks. For the first 2-3 weeks it was awesome. But since then it can't charge beyond 30kWh..... with range in line with that. MG looked at the car for 2 days this week. On MG' s suggestion, I've twice charged the car to the top and fully equalized and then driven until it says "Battery is depleting. Please stop safely". The first time my actual range was 176.6km and the second time it was 173.8km. Oddly, the first drive had aircon on for 80% of the drive, while the second drive had no aircon use.

As it stands now I'm going to return the car for a refund. I like the car but I didn't pay for a car with 1/3 of the battery not available for whatever reason. :-(

Anyone else seen this?
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There is a lot of posts on here about the BMS update. Speak to your dealer to see what version you have got. Basically the lastest versions kills the battery. MG are issuing a new version very soon.
 
@sbwithers your car has the duff BMS like a lot of other cars with similar issues. Nowt wrong with the car per say.

MG are releasing an updated BMS immanently, which is supposed to fix the range, equalisation and loss of power issues.

This has been widely reported on this forum, SpeakEV and Facebook.
 
sbwithers said:
I've had my MG ZS EV for about 8 weeks. For the first 2-3 weeks it was awesome. But since then it can't charge beyond 30kWh..... with range in line with that. MG looked at the car for 2 days this week. On MG' s suggestion, I've twice charged the car to the top and fully equalized and then driven until it says "Battery is depleting. Please stop safely". The first time my actual range was 176.6km and the second time it was 173.8km. Oddly, the first drive had aircon on for 80% of the drive, while the second drive had no aircon use.

As it stands now I'm going to return the car for a refund. I like the car but I didn't pay for a cat with 1/3 of the battery not available for whatever reason. :-(

Anyone else seen this?
.
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What happened after the first 3 weeks of ownership? Did you have an update? You say that you were happy up until then. its true that there is a bms update issue - but if you were fine and then not - unless you had this changed it sounds like something else. How do you know that you cant charge past 30kw? it’s a shame it’s put you off the car but once you loose confidence in it I know how you feel.
 
Paulie68 said:
Out of interest, what voltage is showing when the car is fully charged? It should be over 150v.
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The voltage when fully charged is about 437 to 440. But it seems to be falling. 440v was last week. 437v is this week. Voltage at fully depleted was 387v. It's summer here in NZ
 
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Yes yours is suffering from the BMS software issue, voltage should be about 455 on a full charge, the new update will be out soon contact your local dealer they should be aware of this isssue.
 
Cocijo said:
What happened after the first 3 weeks of ownership? Did you have an update? You say that you were happy up until then. its true that there is a bms update issue - but if you were fine and then not - unless you had this changed it sounds like something else. How do you know that you cant charge past 30kw? it’s a shame it’s put you off the car but once you loose confidence in it I know how you feel.
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After I picked it up on November 14th, I did 3 trips that saw the car perform to expectations. But December 27th saw me drive 660km in a day and I found I needed to charge every 100km. The next day we drove back and it was the same. In the 29th, I called MG and booked a service appointment.

In the meantime, I was able to do some testing. The actual range and efficiency achieved calculate to 29.x kWh every time.

Even the DC rapid charger sees 30kWh, as you can see from the image: 66% having added 19.5kWh. This charge was from fully depleted to "Battery Power is depleting. Please stop safely". On 0%...

That's 2/3s of 30kWh. Exactly what the 173.8km actual distance achieved for 16.3kWh for 100km efficiency indicates. This was in Eco mode with no aircon used.

A third of the battery capacity just isn't there.
 

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sbwithers said:
After I picked it up on November 14th, I did 3 trips that saw the car perform to expectations. But December 27th saw me drive 660km in a day and I found I needed to charge every 100km. The next day we drove back and it was the same. In the 29th, I called MG and booked a service appointment.

In the meantime, I was able to do some testing. The actual range and efficiency achieved calculate to 29.x kWh every time.

Even the DC rapid charger sees 30kWh, as you can see from the image: 66% having added 19.5kWh. This charge was from fully depleted to "Battery Power is depleting. Please stop safely". On 0%...

That's 2/3s of 30kWh. Exactly what the 173.8km actual distance achieved for 16.3kWh for 100km efficiency indicates. This was in Eco mode with no aircon used.

A third of the battery capacity just isn't there.
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Interesting. In November when your car performed to your expectations what range were you getting? You’re completing some very long journeys. (660km/day) having to make 6+ Charge stops must have been a pain. I don’t think I’ve encountered anyone doing those sort of long trips in the MG ZS EV. Has the car been DC charged a lot? It’s definitely one to get back to the dealer to sort out for you.
 
I’d put it on a slow charge and let it fully equalise its self first and see if the calls are fully balanced
 
Just seen this on Faceache...

The Israeli Dealer Customer Service Official Message, received via WhatsApp earlier today, Regarding Battery Range:
Good afternoon, following inquiries regarding battery range, it is important for us to update you with the following information:
As a result of an inaccurate algorithm in the software installed in the vehicles on specific dates, an imbalance was created between the battery cells.
In practice - the battery management computer detects and stops charging when the first cell reaches maximum charge and sets this mode to about 100% charge
As a result, over time and depending on the nature of use and charging, a greater imbalance is created between the cells that the battery management computer did not correctly detect and did not reduce, which actually resulted in a reduction in the amount of energy the battery contains after a full charge and a reduction in the possible range of travel.
The update received from the manufacturer, and tested by us, updates the software of the battery management computer (BMS) and performs a slow procedure of balancing cells while using the vehicle and at the end of charging until reaching an optimal state.
The length of time it will take to reach the ideal balance varies and depends on the condition of the cell balance before the update, the nature and duration of use of the vehicle and charging each day. It is therefore necessary to coordinate an orderly appointment and examine the alternatives to the solution until the end of the treatment. You can contact WhatsApp up back or to * 3038.
We thank you for your patience so far. We will continue to serve you faithfully also in the future, the MG team.
My note:
This morning I brought my MG ZS EV to the dealer’s garage in Haifa, got a FREE replacement (ICE) car till the update is finished (3 to 6 days...)
Well done Lubinski
 
Cocijo said:
Interesting. In November when your car performed to your expectations what range were you getting? You’re completing some very long journeys. (660km/day) having to make 6+ Charge stops must have been a pain. I don’t think I’ve encountered anyone doing those sort of long trips in the MG ZS EV. Has the car been DC charged a lot? It’s definitely one to get back to the dealer to sort out for you.
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The first line drive I did see me travel from Opotiki to Waihi - 193km - and still have 56km left. The battery was still on 24%.

A couple of weeks later - November 26th - I traveled from Opotiki to Auckland (340km) but wasn't able to get to Waihi. Close, but I elected to charge on the way, in Tauranga. Maybe it was windier. I did take a route 12km longer..... so didn't really think much of it at the time.

MG have received my testing results, clearly showing the battery capacity is now just below 30kWh and are forwarding them up the line to the factory.

I've told them I'll return the car for replacement or refund if the matter can't be resolved in a reasonable time. Two weeks.
 
jamesie said:
Just seen this on Faceache...

The Israeli Dealer Customer Service Official Message, received via WhatsApp earlier today, Regarding Battery Range:
Good afternoon, following inquiries regarding battery range, it is important for us to update you with the following information:
As a result of an inaccurate algorithm in the software installed in the vehicles on specific dates, an imbalance was created between the battery cells.
In practice - the battery management computer detects and stops charging when the first cell reaches maximum charge and sets this mode to about 100% charge
As a result, over time and depending on the nature of use and charging, a greater imbalance is created between the cells that the battery management computer did not correctly detect and did not reduce, which actually resulted in a reduction in the amount of energy the battery contains after a full charge and a reduction in the possible range of travel.
The update received from the manufacturer, and tested by us, updates the software of the battery management computer (BMS) and performs a slow procedure of balancing cells while using the vehicle and at the end of charging until reaching an optimal state.
The length of time it will take to reach the ideal balance varies and depends on the condition of the cell balance before the update, the nature and duration of use of the vehicle and charging each day. It is therefore necessary to coordinate an orderly appointment and examine the alternatives to the solution until the end of the treatment. You can contact WhatsApp up back or to * 3038.
We thank you for your patience so far. We will continue to serve you faithfully also in the future, the MG team.
My note:
This morning I brought my MG ZS EV to the dealer’s garage in Haifa, got a FREE replacement (ICE) car till the update is finished (3 to 6 days...)
Well done Lubinski
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I forwarded this to the Service Manager at my MG dealer. He's following it up.
 
Mines still OK...I did an 80 mile trip yesterday with over 60 miles left in "tank". I wasn't hanging about and used the heater all the time....about 4 degrees outside.
 
My car in in at this very moment having the latest BMS update because my UK dealer sent me this.......
Ive just checked MG as I do every morning and there is a new BMS update available. When can I get you booked in?

Still booking from the 18th Jan.
 
Interesting?

May I ask what your range was like pre update? Also, has the dealer mentioned what you can expect from the update?
 
jamesie said:
Interesting?

May I ask what your range was like pre update? Also, has the dealer mentioned what you can expect from the update?
Click to expand...
They don’t have a clue. I prompted them in the first place as persuaded them into the Comfort and BMS a few weeks back and my full charge dropped to 113 miles for N 3
 
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