"Charging interrupted" at 99%, repeatedly.

Lately my car stops charging at 99% on L2, popping up an error on the in-car displays with a check message. This started happening a few months ago when I decided – after more than a year of virtually trouble-free "charge immediately" – to heed the manual and have it finish charging right before my anticipated commute. From the very first "charge in window" it gave me trouble, the first time interrupting charging not long after the start of the window, leaving me with insufficient charge for my return trip; I had to public L2 on the way home.

After some more issues I decided to switch back to "immediately," but the "departure time" remains, though grayed-out. It initially returned to normal but then every so often I'd get to the car, with the pop-up and check message, and a 99% SOC.

Last night I parked outdoors, and my commute was at 4:30 am. While making my espresso, I asked Alexa (My BMW skill) to "warm up my car" and while I was near the front door I could hear the compressor running. I got to my car and was greeted by the check messages and a 92% SOC (after the climatization had been running for 20 minutes, and not using the mains power). I checked the app and saw it had been interrupted at 99% again.

Returning with 80% and a snowfall warning in effect for tonight, I decided to top up again for another 4:30 am commute. This time, the app actually notified me of the interruption at 99%. I opened it and this is the screen:



This is beginning to be a problem.

Any ideas?

 

I just unplugged, turned off the breaker, then blew out the charge port and the EVSE plug with quite a few (deafening) blasts of compressed air. Rebooted the Grizzl-e and tried to get it to handshake for that missing 1%. The car booped and flashed the 99% in red and "Unable to charge." A couple more un-reboot-replugs and it finally completed the handshake while I was holding the plug up as if I were at an EA station. Oy. Anyway, got to 100%. If it happens again I'll unpack the Flexible Fast Charger (for sale on Marketplace), see if it's the Grizzl-e. Doubt it.

 

Guy next door only charges L1 hehe. I can unpack the Flexible and try. It's at 100% now, it completed the handshake and drew the last few joules.

 

Interesting data point. Thanks. Just started a charge (from 74% after just 20 miles in 27° weather with sleet, snow, and wind). If it pops a check message again today I'll unpack the BMW charger for the next charge.

Separately, does anybody know if the charge-scheduling data is stored at the back end, or in the car? Is there any way to reset defaults? When I initiate a charge, the instrument cluster tells me it will be ready at my previously planned, but disabled departure time. After a few minutes and electrons, it shows an updated time that is more in line with charging immediately. Similarly the app shows my previously programmed times, though they are greyed out as they are disabled.

 

I've never scheduled with the (crappy) ChargeLab app. I'm talking about these problems cropping up after the first time I tried using charging window scheduling in the MINI app, and now the software in the car still displays those charging window times, but then charges immediately as requested. I can't find a way to disable the display of the last charging window.

For example, for the three months ending December 1, my workday started at 11:15, so I scheduled charging to be complete by 10:30. I gave up on setting the schedule almost two months ago (deciding that it was more reliable to charge immediately after the first time I got to the car only to find that the battery was at just 11% where I left it the night before), when I plug in, the instrument panel still lights up telling me that the charge will be complete at 10:30 AM. It then goes on to commence charging immediately. ¯\_(ツ)_/¯

 

And I forgot to say thanks for the link, many of those posts seem to describe exactly what I'm experiencing. I also got the information recently about sending my early-2022 Grizzl-e Smart back to them for the upgraded Wi-Fi board, at the pocket-change cost of $150 plus shipping both ways. While I'm impressed with the build quality of the unit, the so-called "smart features" of the EVSE have been a big disappointment and a waste of money.

Earlier this year they told me that they were working on a new app for the EVSE, and thanked me for my patience. It turns out that mine is from an earlier build that cannot accept the new firmware to work with their app. This is BS. So I will probably try the BMW Flexible Fast Charger next time, and if I get no errors I will open up the Grizzl-e and turn off Wi-Fi, making it a "dumb" EVSE for $50 more than the one I could've bought in the first place. I'm really not sure the use of their app will be worth what will amount to at least $200 to fix a problem that shouldn't have existed in the first place.

 

Minor progress in figuring it out on my own.

I've been doing top-up charges almost every night, usually from between 60 and 70% to 100 after my commutes, errands, and unplugged cabin conditioning. Trying to minimize variables, I've limited them to charging and letting it sit plugged-in overnight and then leaving, and charging and letting it sit plugged-in overnight and then asking for cabin preconditioning a few minutes before departure.

It seems the culprit is indeed the plugged-in cabin preconditioning. Whether scheduled, or called from the app manually, the fully-charged battery starts feeding the climate control system, and the car does not draw from the wall, instead popping up the check control messages stating "unable to charge" and the SoC dropping as time goes on. So 10 minutes of conditioning in my 55° garage drops it to 98 or 99%.

 

I will try with and without climate once more (each), then switch to the BMW Flexible Fast Charger and repeat the series of tests. Maybe it is the Grizzl-e, which should still be under warranty, and perhaps they will replace it with the newer version and its upgraded wifi board.

 

I've disabled timed charging. I plug it in for immediate charging, then before departure the following day I call up cabin preconditioning.

 

Not ideal. I'll follow my differential diagnosis, then either seek remedy from MINI, or United.