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Battery capacity

Yes in my case, i have done the 102 mile round trip several times over the last couple of months.

The first time, the car came home with 30 miles in the tank, the second time, I had to recharge at about 70 miles, and last night I had to recharge at about 80 miles. When I say had too, I HAD to with 4% of the battery left.

So I do feel the range is getting worse, fully charged voltage is 440v or so. As said the car is going to have its update this week...
Sounds very similar to the issues I’ve been encountering. Be interesting to see how things change/improve once you’ve had the update this week.
 
Another disappointed customer..This weekend I set out to do a 51 mile journey, starting with 141 miles on the GOM. Arrived at my destination with only 54 miles left. All motorway, speed 60-65mph, no heater etc.

When returning, I had hoped to cover the next 20 miles to a motorway rapid charger, but only just got there with some 4% left on the battery. And then another car was using the rapid, so I used the 7Kw charger until he left. I then charged up to 80%, the GOM showing some 116 miles. The final leg home was only 30 miles, arrived home with 49 miles on the clock, using a one bar of heater occasionally. Temps were about 4'C.

Something not right there at all.

The car is going for an update to software this week, and not too soon.

Patience is wearing a bit thin to say the least..........Grrrrrrr

Re the GOM. Unfortunately it is a Guess O Meter, so it tries to calculate it as best it can, but it cannot accurately predict what type of driving you are going to do in it next.
Knowing how the GOM calculates will allow you to make more realistic predictions.
It bases its calculations (we think) mainly on what is recorded in the accumulated trip; so if the miles per kWh in the accumulated trip roughly matches what you think you'll be getting on your next intended journey, then it shouldn't be "too" far out.

Your limited 51 + 20 miles journey range was awful. Yes it was all motorway (worse possible conditions), but if doing 60-65mph with no heater and temp was 4c, then on a full charge you should def get over 100 miles range.
Obviously I cannot comment on how you were actually driving lol.
My new car is doing 102 miles mainly motorway journeys 3 days a week, so I have reasonable data for comparison over the last month.

What I will say is, it's very important to know what your miles per kWh are for the journey you've done. As that is the only true measure of how many kWh you have actually used - which can then be compared to what the battery capacity is supposed to be to see if you have an issue.

What is your voltage when it's fully charged, this shows up if your battery has gone pants due to the BMS bug.
 
That could possibly account for the drop in the battery capacity although been mixing up the charging between rapid chargers and 22kwh ones. I’ll get in touch with the garage on Monday but thanks for your help.
Do you really mean "rapid chargers and 22kwh ones" As 22kWh is a rapid charger.
The fundamental difference is if it's DC vs AC.
AC charges allow a battery cell balance to occur at the end of the charge, DC do not.

I wouldn't hold out much hope, but if I were you I'd go back to the dealer and try to insist that they spend the time and energy to "fix" your battery and give you a car to use in the meantime...
 
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My car had the bad BMS software from late last year and the full battery voltage was down at 433v, with a range of 70-80miles..
I have had the new BMS software. Not including charging from mileage travelled, I have now done around 80 hours of balancing charges and the full voltage is 437v, so on average, approximately 20hours of balancing per volt increase.
With 13v still to go to get up to 450v, it looks like I will have a further 260hours of balancing charges to complete..
All this is being done at my own cost and inconvenience.
That's really bad that you were down to 433volts.
You deserve some sort of compensation from MG.

The problem is, unless the battery capacity is below 70%, then technically MG don't have to do anything as it's within their warranty terms....arghhhhh.
There are probably other consumer laws that maybe applicable but would need to be proved etc.
 
Does anyone know the approximate difference (if any) in the available top and bottom voltages between the latest update and say the 455v software? So, mine is fully charged all accessories off 455v - after the point where the battery warning light starts flashing (around 15 miles left for me) is about 380v. Giving voltage range of about 75v. I’m guessing that it will be about between 450v and 375v give or take on the latest BMS when it’s functioning correctly?
 
That's really bad that you were down to 433volts.
You deserve some sort of compensation from MG.

The problem is, unless the battery capacity is below 70%, then technically MG don't have to do anything as it's within their warranty terms....arghhhhh.
There are probably other consumer laws that maybe applicable but would need to be proved etc.
It’s a good point - but on a new car I think you’d have a strong case to say the car is not performing as advertised and within specification - if MG played the 70% card on a very new car I’d be very disappointed.
 
Does anyone know the approximate difference (if any) in the available top and bottom voltages between the latest update and say the 455v software? So, mine is fully charged all accessories off 455v - after the point where the battery warning light starts flashing (around 15 miles left for me) is about 380v. Giving voltage range of about 75v. I’m guessing that it will be about between 450v and 375v give or take on the latest BMS when it’s functioning correctly?

Maybe between us we can get a definitive answer or this, as currently it is an unknown.

You def don't have the dodgy Oct BMS do you?
Mine had never been used before the jan fixed bms was applied, so I'm at full valid new version/voltage.

We need to run our cars down COMPLETELY empty to see the true bottom voltage.
When the wife gets home after her long work journey tomorrow, I'll leave the car sitting with heater on full etc on driveway, then when it's completely flat see what the voltage is.
If you can do the same with yours, we will get the result.
(I wanted to do this last week but she'd already plugged it in when she got home)

Unfortunately I don't have a proper home charger yet, so will not be able to see how many kWh it then takes to do a verified full charge, if you have then that would be brilliant information to see.
 
It’s a good point - but on a new car I think you’d have a strong case to say the car is not performing as advertised and within specification - if MG played the 70% card on a very new car I’d be very disappointed.
Yeah I think there's laws about it having to perform as it was bought within the first year or something, it was all a bit complicated and a bit vague.
Shame no one who's a lawyer in this area has the car with the issue, as they may well be able to reasonably get the case tested!!!
 
Maybe between us we can get a definitive answer or this, as currently it is an unknown.

You def don't have the dodgy Oct BMS do you?
Mine had never been used before the jan fixed bms was applied, so I'm at full valid new version/voltage.

We need to run our cars down COMPLETELY empty to see the true bottom voltage.
When the wife gets home after her long work journey tomorrow, I'll leave the car sitting with heater on full etc on driveway, then when it's completely flat see what the voltage is.
If you can do the same with yours, we will get the result.
(I wanted to do this last week but she'd already plugged it in when she got home)

Unfortunately I don't have a proper home charger yet, so will not be able to see how many kWh it then takes to do a verified full charge, if you have then that would be brilliant information to see.
Ok - my BMS is fine but obviously not the Jan21 450v one. I will run it out and look at the voltage. What are we using as a measure? Is it the point it shows zero range left? I don’t think you can get voltage if you run it until it actually shuts systems down - although it may be displayed. We might be a little off with voltages but it will be a reasonable reference.
 
Ok - my BMS is fine but obviously not the Jan21 450v one. I will run it out and look at the voltage. What are we using as a measure? Is it the point it shows zero range left? I don’t think you can get voltage if you run it until it actually shuts systems down - although it may be displayed. We might be a little off with voltages but it will be a reasonable reference.
Hmm I'm not sure to be honest, I'm not sure what happens when it gets that low.
After 10 miles on the GOM it goes ---, I ran it down a couple weeks ago to what I think was 6miles left on the GOM. That's the lowest I've ever gone.
Not sure what it'll do when it gets to "zero" sitting stationary with heating on.

That guy who experienced running out on the motorway may know.
But realistically we're not going to actually see it run out - unless you're planning on sitting in the car watching it lol.
Ooooh, I could stick one of my cameras in the car recording the dash, with it on the voltage screen, then could play it back...

I would guess that once it "runs out" and switches off, usually with batteries after a while they recover slightly and you can get them briefly back on, so hopefully we'll be able to do that and get the voltage quickly.
 
I am confused.

After a full charge my battery shows 439v and a displayed 169 miles of range in 'N'. I had comfort 2 carried out in December but I think I need the latest (15-01-2021) BMS update to get to 450v.

When I had the updates carried out in December my range dropped to a poor 125 miles in 'N' after a full charge. I recently reset the m/kWh cumulative and per trip and this increased the range to 169 miles at full charge.

My car goes in for service next week but I am unsure if I should request the latest BMS update as the range is back to 160+ miles, were it was when I bought the car, with pre comfort 2/BMS update.

Any advice?
 
Re the GOM. Unfortunately it is a Guess O Meter, so it tries to calculate it as best it can, but it cannot accurately predict what type of driving you are going to do in it next.
Knowing how the GOM calculates will allow you to make more realistic predictions.
It bases its calculations (we think) mainly on what is recorded in the accumulated trip; so if the miles per kWh in the accumulated trip roughly matches what you think you'll be getting on your next intended journey, then it shouldn't be "too" far out.

Your limited 51 + 20 miles journey range was awful. Yes it was all motorway (worse possible conditions), but if doing 60-65mph with no heater and temp was 4c, then on a full charge you should def get over 100 miles range.
Obviously I cannot comment on how you were actually driving lol.
My new car is doing 102 miles mainly motorway journeys 3 days a week, so I have reasonable data for comparison over the last month.

What I will say is, it's very important to know what your miles per kWh are for the journey you've done. As that is the only true measure of how many kWh you have actually used - which can then be compared to what the battery capacity is supposed to be to see if you have an issue.

What is your voltage when it's fully charged, this shows up if your battery has gone pants due to the BMS bug.
@JodyS21
You are right in the comments you have made except that the GOM actually uses only data for the last 10 to 20 miles (in some cars even less). This is because statistically it data is deem closer and more predictive for the current conditions you are driving in than what your accumulated data from last summer would show. The GOM self updates every 30sec to 1min so that is why when the weather is cold the GOM starts to show lower numbers and in the summer the numbers improve.
 
I am confused.

After a full charge my battery shows 439v and a displayed 169 miles of range in 'N'. I had comfort 2 carried out in December but I think I need the latest (15-01-2021) BMS update to get to 450v.

When I had the updates carried out in December my range dropped to a poor 125 miles in 'N' after a full charge. I recently reset the m/kWh cumulative and per trip and this increased the range to 169 miles at full charge.

My car goes in for service next week but I am unsure if I should request the latest BMS update as the range is back to 160+ miles, were it was when I bought the car, with pre comfort 2/BMS update.

Any advice?
@Dr Dave
From the little that you have written, I will say confidently that there is absolutely nothing wrong with your car.
I know a lot has been written about this update in regards to voltage, upper and lower buffers, GOM etc but the truth of the matter is that unless you are someone who drives till the GOM shows zero before you top up then there will be absolutely no effect on your actual driving range from this update. On paper it is good to have in that it makes more battery available but unless you get it done at a dealership who know what they are doing you may end up with more trouble than any practical benefit.
Also the change in your GOM numbers may actually have had nothing to do with the GOM reset as such. Could explain further but main thing is that your car is absolutely OK going by what you have written.
 
I got the new update on the 22nd February and have only had the car since December so will not be happy if I get told I need to do hours upon hours of equalisations to get the battery back to what it was when I bought the car - It’s so frustrating as the car is so lovely to drive.
When I put it on the rapid charger it showed on the charger screen that my battery pre charging was approximately 6% and once it finished charging it showed 28kwh on the screen. My car dash also had the message charging complete. Then when I took it home and used the home charger which displays the usage on the app, it showed 3kwh went into the battery after around 4 hours of charging (obviously this includes equalisation).

Prior to the update, we were finding a similar issue which I think has got worse over time and the range has been rather unpredictable, especially when the range is showing 140 ish and we’re only completing a 70 miles round trip, with heating off and outside temperature around 9 degrees celsius, the final range shows 16 ish miles left and just can’t help but think this is due to the car not utilising the full battery capacity when allegedly charging to full.
@Chrissunray
I think you car definitely needs to go back to the garage.
You are right. It seems the whole of the battery is not being utilized.
It is more likely a software problem from a misapplied update but may also be a battery pack problem. There is no way of excluding a battery pack problem yourself so my advice will be to send it in.
One problem is that when you go to the dealerships your problem is recorded by a service clerk/receptionist. You will need to make sure that what the clerk has written is exactly what you want to tell the technician. Infact ask the clerk to call the technician so you can tell the tech yourself if possible. With EVs, these clerks are still learning and often what the these clerks write is far removed from what the actual problem is.
 
Story so far. BMS update done in Nov, we all know what happened then. It has now been 10 days since my recent 2021 BMS update. Voltage has reduced from 456v down to 450v, Range has dropped 30mls on GOM on a full charge, car still will not do a delayed charge on Smart Charger although Charger will work normally with doors unlocked. Numerous charges have been done everyday since update although battery charge has really never dropped below 70%. I have been leaving the charger on all night to make sure the car balance charges. I am finding that when I go to disconnect the Charger the following day the charger lock disengages and within about 3 sec it re engages the lock and starts a balance charge again? I can only assume the battery is still trying to rebalance itself since the update. Anyway will contact Dealer tomorrow to see what they intend doing regarding the delayed charging issue. By the way just to check it was not my Smart Charger that was causing the issue I had my Son inLaws car here this weekend doing numerous delayed charges on his car each one working as it should so there is no doubt it is the MG that is causing the issue and not the Charger.
 
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