Limiting max charge level (tip)

It is possible for an EVSE to get charge % from the car, using the protocol for DCFC. This is a lot more complex than the rgeular AC charge communication, though. I don't know of any AC EVSEs that do this.
I was doing some basic maths to calculate the charge time and set the start and stop times in my EVSE. "Was" as my car has some weird charging glitch. It sometimes need the locks toggled to begin charging. So currently, I plug in when I get home and check it starts. I don't want to be checking on it hours I leave for work...
I have an openEVSE. yep, open source. Just in case I wanted to add features. One possible feature would be to look for a charging negative deltaP of maybe 10%.
As many of you will have noticed, charging current and power starts to drop as full charge is approached. I think it's at around 95% for maxxed out AC charging. Still better than 100%. Somewhat harder, would be for the openEVSE to interrogate the car for charge %. The communication standard is behind a paywall that I haven't coughed up for, though.

 

I have the Autel Smart charger. I use it with an app called Monta (might only work in Denmark, though I’m not sure). Basically Monta speaks to the app whilst also speaking with the Mini. Trough the Monta app you sign in to your Mini account. This makes it possible to choose the exact amount of power you want on the car as Monta receives the information from the Mini App. Very clever!

I always charge to 80% unless I need the full charge.

 

I don't think the J1772 protocol provides anything beyond charging and the duty cycle via control pilot pulse width modulation. CANBUS protocol for the Nissan Leaf, Teslas or Chinese vehicles (ChaoJi/CHAdeMO 3.0) will have SoC % available for level 2 charging.

The only way is probably a backdoor via the MINI app as Rasmus Aage said above. Others have pointed out indirect methods like total kWh limits or time-based charging.

 

I'll be surprised if the J01 doesn't allow a charging limit.

 

Probably only available if you have ChaoJi, the "Chinese Charging Standard 3".

 

Found the charge limit in expert mode.

HU_NBT_EVO > 3000 HMI > BATTERY_CONTROL_SOC_T... > 100 (0x00)

 

Can you set up one of these SOC selections to be activated by a button? Would you need to use a second button to go back to 100%? Or is there a secret SOC menu that could be set up for access through a button?

 

Wild how it’s there but not implemented. I’m curious if you can get it working

 

I think a hot button could only control it if it brought up a selection screen in iDrive

 

That's very interesting, but I'm still getting the same range after 73,000 miles that I got on day one, and I charge to 100% SoC every day. I think MINI perfected the built-in battery management. It's really nice to not have to give any thought to charging. Just plug it in.

 

I'm in the UK, but my car charger (Ohme) can interface with the Mini app on my phone and read the current SoC, so I have it set to charge to 80% and whenever I plug it in, it checks the current charge and creates a charge schedule to hit 80%

 

Well I poked around a few other settings. There is a battery control menu available but you can't change the settings with the iDrive controller or touchscreen.

 

I wonder if there's another setting to make the activated menu accessible?

How many BMW/MINI engineers have the knowledge to write a full-bore Bimmercode manual? If the number is small, then it would be difficult to write such a manual and remain anonymous. However, if the number is large...somebody do it!

 

I think those are latent items from i3 software.

 

Probably from the i3 range extender.

 

The BMS isn't FDL or FA coded though, and "100%" is actually 80% charge. I'm in the camp that thinks there is no reason to limit charging to 80% indicated, because the BMS already limits to 80% (or thereabouts) actual. Leaving it plugged to 240/32 also allows the BMS to balance the cells, which was actually recommended for the i3's various packs.

 

There’s nothing special about the mini cooper battery or management system. It’s all old tech borrowed from the i3. i3 cars have had to have a ton of battery replacements.

virtually all modern EVs go with an 80-90% charge scheme for good reason.

 

MINI chose to implement an uncommonly large top buffer. It would be very interesting to see the buffer values for all the EVs on the market.

In the following diagram the SE's top buffer would be basically "A" and "B" combined.

 

I don't get it. How would one go about getting the battery to charge to "100% for long trips" vs "normal end on charging"? No doubt it would be a cool feature