Balancing the battery

[Hans]

I'm based in The Netherlands and own my MG for a little over1 year. Until oCotoberI wa happy with the performance in general and also with the range. Loading at night showed a range in the morning of around 250 km. Then in October a new BMS was installed, which was later acknowledged by the dealer to have flaws. Loading at night showed a range in the morning of no more than 190km and worse 1. the car needed over 100km range for a actual distance of less than 50km and 2. at a level of 20% the battery, the car would not do more than 90 km/hour at a maximum of 25% of its power.
The offered solution was to "balance" the battery, which could take upon to 14 days. The car is at then dealer for this process. I'm really curious if the performance is up to level as shown in the specs.
My question is, does anyone has heard of this problem and does anyone has an experience with "balancing"the battery. I'm really curious.

 

[mystreet]

Hi Hans,

Welcome to the forum.

There is a lot of information in the posts. Main one to read is this one.

 

[Hans]

Hi Hans,

Welcome to the forum.

There is a lot of information in the posts. Main one to read is this one.

Thank you

 

[AV2EV]

I'm based in The Netherlands and own my MG for a little over1 year. Until oCotoberI wa happy with the performance in general and also with the range. Loading at night showed a range in the morning of around 250 km. Then in October a new BMS was installed, which was later acknowledged by the dealer to have flaws. Loading at night showed a range in the morning of no more than 190km and worse 1. the car needed over 100km range for a actual distance of less than 50km and 2. at a level of 20% the battery, the car would not do more than 90 km/hour at a maximum of 25% of its power.
The offered solution was to "balance" the battery, which could take upon to 14 days. The car is at then dealer for this process. I'm really curious if the performance is up to level as shown in the specs.
My question is, does anyone has heard of this problem and does anyone has an experience with "balancing"the battery. I'm really curious.

Exactly the same story here in Israel. I had a lot of problems after the update, the range dropped 80 km, constant warnings "Slow Charge the Vehicle", one cannot trust the numbers of remaining km at all. The other day it showed a "Low Charge" warning at 96 km. The car is at the dealership for 10 days already, using their car.

 

[Hans]

My car is now 14 days at the dealer. Talking to a mechanic did not cheer me up. If I understood it well the difference in Volts per cell must not exceed 100mV. To achieve that is trial and error, also time consuming and unpredictable in terms of time. The approach now is upload und unload until the ceiling of 100mV is not surpassed.
They had a lot of cars with the same problem, but MG The Netherlands does not offer a better and more efficiënt solution. On top of that they could not say whether to battery can be fully charged to reach 455 Volts, or that the voltage has been reduced by orders of the factory from 455 volts down to around 449 - 450 volts may have been as a result of cars blowing the HV fuse !)
Also the question “can this battery problem occur again” was left unanswered.