Supercharging Limited to 12A

[GM99]

Last couple of supercharging sessions for M3 SR+ has seen the charge current limited to 12A so only getting 34kW (c160 miler/hour). Any one have any idea?
Also apologies if I’ve missed it but have seen that the increased supercharging rate for SR+ was removed from the latest software update. Do we know what’s happening with this?

 

[NorfolkMustard]

Hi,

You can ignore the Amps setting when using any DC fast charging, it's not relevant. It's greyed out to try and explain that but it could be better.

your low rate could be explained by other reasons:

• Rate tails off as your battery state of charge (SoC) increases -> This happens sharply from ~60% SoC but your rate in the picture seems lower than you would expect if this were the only reason - it would be at 35kW by about 85-90% SoC
• Rate is limited if you are sharing a numbered pair of supercharger stalls with another car who got there before you did -> Avoid sharing the second stall in a numbered pair you'll get between 37kW and whatever's left after deducting the other car's rate from 150kW
• Rate is limited if the battery is cold -> use the in car map to navigate to the supercharger so it preconditions the battery (warms it)

 

[GM99]

Hi @NorfolkMustard, thanks for the response. I was the only car on a numbered pair, therefore assume that it must be due to a cold battery. Had set to pre-condition but only for about 10 mins. Does it need longer than that?

 

[vitesse]

Hi @NorfolkMustard, thanks for the response. I was the only car on a numbered pair, therefore assume that it must be due to a cold battery. Had set to pre-condition but only for about 10 mins. Does it need longer than that?

Yes it needs much longer and on its own may not warm the battery enough for fastest charging. A decent drive beforehand is the most effective way to warn the battery and set the nav to the target Supercharger so the car itself will work to warm the battery on the way.

 

[WannabeOwner]

Had set to pre-condition but only for about 10 mins. Does it need longer than that?

In Winter, if option is available, you are better off charging night-before (e.g. staying at Hotel) rather than morning-after, unless you have a decent length of morning drive before getting to Supercharger. In Winter when leaving home I typically have 20 minutes of reduced Regen, due to cold, and optimum temperature for battery charging would need higher temperature still ... although if SatNav destination set to Supercharger location then battery heating might achieve that in that sort of time, but "battery starting at winter cold" probably not in 10 minutes driving / pre-conditioning. Charge battery for an hour before departure might help, and possibly Scheduled Departure / cabin heating before departure might do too, but facts about whether-it-does or whether-it-doesn't are hard to actually pin down ... and might well be different in previous/next software update