Low Battery - Reduced Power

[JodyS21]

I agree, it is a strange choice to show voltage. kWh would indeed make more sense. In order to meet the differing ranges of user knowledge, the straightforward number of bars, that mimics an ICE car is probably the easiest to understand. kWh could be an option to show for users that really want to know that information but I think the EV car manufacturers should invest some space in the manual to explain battery characteristics and what kWh mean if it is going to be shown. I remember the old Ford Cortina mkIII GT with dials showing oil temperature, crank case pressure etc. Did we need to know those things or were they just fun to know. Some users love that kind of information and will research what the significance of these values are. Anything that requires a knowledge of battery chemistry/characteristics, electrical theory and the like should probably be abstracted away from the user. It would be interesting to know the decision process that went into showing voltage.

I've got to say, I don't like the battery bars bit under the power meter. It's not a linear scale is it from what I can tell. When it's so important in an electric car unlike an ICE (that you can easily/quickly fill etc) I want a more accurate digital display/figure.

 

[DriverInNorway]

I've got to say, I don't like the battery bars bit under the power meter. It's not a linear scale is it from what I can tell. When it's so important in an electric car unlike an ICE (that you can easily/quickly fill etc) I want a more accurate digital display/figure.

Yeh, there are not enough bars. It would be better if there was greater granularity and if it was linear. My ICE car had a non-linear fuel gauge too. Stayed for ages on full, then rapidly ran out when it was down to two bars. Felt like the fuel tank was funnel shaped. I guess for EV s we are still at the early stages of the technology. The replacement car I am driving seems to have a pretty good algorithm for the remaining range though. I don't know how good the GOM is on the ZS EV as I think I always had it with the buggy software. I am hoping to see an improvement in this when I get it back.

 

[AV2EV]

Avoid the December BMS update. Had a lot of problems after the BMS update in early December - the range dropped about 100 km - the real range now is about 140 km only. Every day I get multiple warnings "Slow Charge the Vehicle" although I have slow charged the vehicle almost every night. One cannot trust the numbers of remaining km at all. One has to divide it by 2 to get the realistic range after the update. The other day it showed a "Low Charge" warning at 96 km... Moreover, the voltage is down to 428 and even 419 volts. Something stinks here.
The car has been at the dealership for more than 20 days, I’m using their car - at least this is nice. They are struggling to get it back to normal.
I'm not the only one - met a guy with similar problems from another city - his car is in the MG garage for two weeks already.
Yesterday they called me from the MG garage Jerusalem and said that my car will soon be ready - the truth is, however, as I was told that there are other clients lining up with exactly the same problem and they need their demo car back...

 

[DriverInNorway]

Finally, tomorrow I collect my car from the dealers. i have to give the Tesla loan car back. To be honest, I am looking forward to it. It has been fun to have stupid acceleration but totally useless with the speed limits and totally not worth the price. I hope to be able to report good things about the range and battery in the next couple of weeks.

 

[DriverInNorway]

Amazing what working software can do! I drove my car everyday last week and didnt need to charge it once. I wont mention the range because it is quite mountainous here, so not truly representative. However, before the update, at its worst, I was only making one return journey to work before it needed recharging. Also, all the power is now available until the battery is really low, I think around 20km it goes into limp mode. Prior to the update, it was limiting power to 40% when the battery had over a third of the power left. So, all good. Disappointing there was such a debilitating bug and MG didnt do a more proactive recall but the dealer here was fantastic.

 

[WAC 768]

Amazing what working software can do! I drove my car everyday last week and didnt need to charge it once. I wont mention the range because it is quite mountainous here, so not truly representative. However, before the update, at its worst, I was only making one return journey to work before it needed recharging. Also, all the power is now available until the battery is really low, I think around 20km it goes into limp mode. Prior to the update, it was limiting power to 40% when the battery had over a third of the power left. So, all good. Disappointing there was such a debilitating bug and MG didnt do a more proactive recall but the dealer here was fantastic.

Glad to see you've finally got the car back and all the issues have been resolved . I'm still suffering with the limited power even with all the latest updates and good battery voltage (449v)

 

[Mike]

Glad to see you've finally got the car back and all the issues have been resolved . I'm still suffering with the limited power even with all the latest updates and good battery voltage (449v)

Keep on equalisation regime for a little longer I would suggest.

 

[WAC 768]

Keep on equalisation regime for a little longer I would suggest.

Booked in at the dealers for them to do, let’s hope this resolve it ?

 

[JodyS21]

Amazing what working software can do! I drove my car everyday last week and didnt need to charge it once. I wont mention the range because it is quite mountainous here, so not truly representative. However, before the update, at its worst, I was only making one return journey to work before it needed recharging. Also, all the power is now available until the battery is really low, I think around 20km it goes into limp mode. Prior to the update, it was limiting power to 40% when the battery had over a third of the power left. So, all good. Disappointing there was such a debilitating bug and MG didnt do a more proactive recall but the dealer here was fantastic.

It's a strange one this power limiting, a few people were suffering with it and others weren't despite seeming to have the same software.
Good you've got it sorted out now.

 

[WAC 768]

Not looking good but at least i'm understanding the problem a little better . It all appears to be battery temperature related and if the car is left overnight with around 15% SOC, then i will experince low power anything from 25 - 50%, even after driving the car for a number of miles and depending on overnight temperatures. Once the batteries are hot and after many, many miles even when i have driven the car down to 8% SOC, 100% power is still available which also explains why my rapid charging speeds are varying so much and only after 130+ miles am i actually getting close to a 50KW charge rate.

 

[JodyS21]

Not looking good but at least i'm understanding the problem a little better . It all appears to be battery temperature related and if the car is left overnight with around 15% SOC, then i will experince low power anything from 25 - 50%, even after driving the car for a number of miles and depending on overnight temperatures. Once the batteries are hot and after many, many miles even when i have driven the car down to 8% SOC, 100% power is still available which also explains why my rapid charging speeds are varying so much and only after 130+ miles am i actually getting close to a 50KW charge rate.

Does that suggest that the battery temperature management system isn't working properly?

 

[WAC 768]

Does that suggest that the battery temperature management system isn't working properly?

I beleive the car only as 'Active cooling' and not 'Active heating' although there is a heater but this is only used when the temperature is well below freezing but i could be wrong? Maybe the TMS is bringing on the cooling too early, but i've only ever heard the pump running whilst charging after a 130+ mile trip, all other times the car is silent whilst rapid charging. If my thoughts are correct then I suspect the lack of 'Active heating or ability to maintain the optimum temperature' is the root cause and probably most cars are suffering the same, but if you only charge at home every night or use rapids only for long journeys then this may never be seen...

 

[JodyS21]

I beleive the car only as 'Active cooling' and not 'Active heating' although there is a heater but this is only used when the temperature is well below freezing but i could be wrong? Maybe the TMS is bringing on the cooling too early, but i've only ever heard the pump running whilst charging after a 130+ mile trip, all other times the car is silent whilst rapid charging. If my thoughts are correct then I suspect the lack of 'Active heating or ability to maintain the optimum temperature' is the root cause and probably most cars are suffering the same, but if you only charge at home every night or use rapids only for long journeys then this may never be seen...

You are probably right that it only as standard does active cooling of the battery, in some cold countries they've enabled battery heating.

If you can document in detail a few scenarios that cause the problems, maybe some others of us can replicate them as accurately as possible.

 

[WAC 768]

You are probably right that it only as standard does active cooling of the battery, in some cold countries they've enabled battery heating.

If you can document in detail a few scenarios that cause the problems, maybe some others of us can replicate them as accurately as possible.

Here's the steps you can follow:

1) Run the car down to between 16 - 20 miles and leave overnight.
2) Following morning, with the AC & heater on, drive up a small incline and from around 20 MPH, floor the accelerator, you should get anywhere between 25 - 50% power (temperature dependant).
3) Charge the car at a known good rapid charger I.E BP Pulse, Instavolt etc. upto 80% whilst taking note of the charge speed.
4) Drive the car on the motorway at a constant speed, down to the same 16 - 20 miles, repeat step 2 and you should now see 100% power.
5) Repeat step 3 using the same charger immediately after the drive and hopefully you'll get close to the maximum the charger can supply.

I will be very interested if anyone tries to replicate this and see what results you get.....

 

[Mike]

I understand the active temperature management kicks in around -10°C. It may be as high as -5°C, but I’ve never experienced it and the battery heater I haven’t been able to force on using the software ‘switch’.