2021 MG5 Battery Care

[Paul Hampshire]

Hi, I have recently acquired a 2021 MG5 with 50k miles. Battery health 94% according to garage check / certificate when i bought it. Typical max range 200 - 205 miles so far. Will be almost always charged up at home on 7kW charger.

How often should I charge to 100% (instead of 80%) charge to properly do the "Equalisation" process....monthly? I gather than when get to 100% need to leave it on charger for a few hours to properly complete the Equalisation process. How many is "a few" - anyone got any views on this please? Thank you.

 

[Jomarkh]

Hi, I charge my two MG5'S to 80-90% and on an Octopus green energy night to 100% monthly or there abouts. If you do it regularly then it does take much longer once it reaches 100%

 

[MickeySw]

The MG5 (FL) user manual states the following:

“When using the vehicle on a daily basis, it is recommended to fully charge it at least once a week, which is conducive to the health maintenance of the high-voltage battery pack; every 3 months to half a year, a low-power (less than 10% or 1 grid) full charged is performed.”

MG’s recommendation seems to be is to balance charge once a week and to re- calibrate the BMS about three times per year.

 

[Paul Hampshire]

The MG5 (FL) user manual states the following:

“When using the vehicle on a daily basis, it is recommended to fully charge it at least once a week, which is conducive to the health maintenance of the high-voltage battery pack; every 3 months to half a year, a low-power (less than 10% or 1 grid) full charged is performed.”

MG’s recommendation seems to be is to balance charge once a week and to re- calibrate the BMS about three times per year.

Thanks Mickey, much appreciated. To clarify:

1/. Mine is an NMC battery not an FLP one - does the above advice apply to NMC? (I note the "FL" in brackets at the start of your comment).

2/. Most advice seems to be to use / charge between 20% and 80% capacity routinely and then every (say) 4 - 6 weeks to fully charge to 100% and leave it a few hours after then to let it fully rebalance. This seems to be different to what you are saying?

3/. What is the "BMS" you refer to please?

Again thank you Mickey, hope its ok to ask these follow-on questions...!

Cheers, Paul

 

[Gomev]

Hi, I have recently acquired a 2021 MG5 with 50k miles. Battery health 94% according to garage check / certificate when i bought it. Typical max range 200 - 205 miles so far. Will be almost always charged up at home on 7kW charger.

How often should I charge to 100% (instead of 80%) charge to properly do the "Equalisation" process....monthly? I gather than when get to 100% need to leave it on charger for a few hours to properly complete the Equalisation process. How many is "a few" - anyone got any views on this please? Thank you.

As aften or as little as you want or is convenienent.
Leave it as long as you can, once it's done it won't come to any harm if it's still plugged in. It also won't come to any harm if you unplug it while it's still balancing.
The more often you do it the quicker it is. Could be less than 10 minutes, could be an hour or more, depending on how long between.
Key part is though, don't lose sleep over it.

 

[Pete G]

Hi Paul, the BMS is the battery management system electronics. It checks each cell and makes sure that they are all charged to the same level.
Pete

 

[MickeySw]

Thanks Mickey, much appreciated. To clarify:

1/. Mine is an NMC battery not an FLP one - does the above advice apply to NMC? (I note the "FL" in brackets at the start of your comment).

FL relates to the ‘face lift’ model, yours is it’s predecessor although it’s using the same battery system (NMC chemistry)

2/. Most advice seems to be to use / charge between 20% and 80% capacity routinely and then every (say) 4 - 6 weeks to fully charge to 100% and leave it a few hours after then to let it fully rebalance. This seems to be different to what you are saying?

I’m merely quoting the manual which suggests to do a balance charge once a week and a deep discharge (10%-100%) to re-calibrate the BMS (SoH) every couple of months.

That said, I generally run within the 40-70% range most of the time and only charge to 100% (and leave it plugged in) when I need the extra range (about once a month). Never felt the need to re-calibrate the BMS.

Modern NMC cells are will outlive the rest of the car, as long as you don’t leave your EV sitting fully charged or empty for weeks on end SoC range used is irrelevant.

3/. What is the "BMS" you refer to please?

As already mentioned by @Pete G

 

[emmrecs]

@Paul Hampshire

You do need to be aware that with the pre-facelift MG5 there is no method to limit the charge to 80% other than manually turning off the charger at the appropriate time! The FL (facelift) version does include that facility, via the iSmart app and the car itself.