State of charge inaccurate and inconsistent.

[Tux]

Hey all,

My CE 04 has been misreporting its actual state of charge (SoC).
Several times I have parked in the 60s% but when I return the next day, it displays 100% and slowly comes down to to the correct SoC.
Then today. about 15 mins into my ride the SoC dropped 10% in 1min from 60% to 50 %, Returned home with 46%, When I check the bike a couple of hours later it was displaying 62%.

Has the SoC been acting up for anyone else? Is it worth contacting BMW over?

 

[Low On Cash]

While there could be some inaccurate reading on the display, 60 to100% is not right. You might want to hook up an OBD reader and see how accurate the display SOC is to the OBD values.

Mike

 

[triangletom]

That does sound very weird - I'd talk to a dealer about it.

I have seen inconsistency where the BMW CE-04 momentarily believes it has charged to a higher rate than it has: for example, I'm at a charger and it goes up from from 80% to 85% unnaturally fast, but when you leave the parking lot it drops back down to 80%, stabilizing after that.

I've never seen it behave inconsistently for a full 100% charge though.

 

[BodenM]

I have had a single instance of after charging at a public charger to about 75%, shortly after setting off the SOC dropped to 44% and got stuck there for the next 35km until I got home and plugged it in to fully recharge, after which it fixed itself and hasn't happened again. I mentioned it to the dealer at the first service and they reported nothing seemed amiss, and it hasn't happened since that one time so I'm chalking it up to a momentary lapse of sanity from the battery controller

 

[Glengormley]

Hey all,

My CE 04 has been misreporting its actual state of charge (SoC).
Several times I have parked in the 60s% but when I return the next day, it displays 100% and slowly comes down to to the correct SoC.
Then today. about 15 mins into my ride the SoC dropped 10% in 1min from 60% to 50 %, Returned home with 46%, When I check the bike a couple of hours later it was displaying 62%.

Has the SoC been acting up for anyone else? Is it worth contacting BMW over?

I have experienced the same issue multiple times over the last few months. Currently the bike is with the dealer (two weeks now) Software update has not improved things and I understand there are error codes.
My local dealer is not qualified to service beyond a software update and bike may need shipped to address problem to sort the problem.

 

[Tux]

I have experienced the same issue multiple times over the last few months. Currently the bike is with the dealer (two weeks now) Software update has not improved things and I understand there are error codes.
My local dealer is not qualified to service beyond a software update and bike may need shipped to address problem to sort the problem.

Sorry to hear you have had the same issue, I hope BMW can get to the bottom of it.
The only thing I can put it down too is temperature variation (its winter here).
I'm going to book mine into BMW to get it looked at too.

Let us know how you go, and good luck.

 

[Tux]

My CE 04 stopped being able to be charged. BMW replaced the LIM (charging module) it seems to have fixed the miss reporting issue.

LIM diagram from i3

 

[Bestaflex]

Hi, I found this thread on google because I have a somewhat similar problem to what you had :

- Displayed range is about half of what it should and what i can do. Usually after a full charge i see 100%-55km while i know i can do 80-100km depending of highway or city routes. usually it levels with time 75%-45km then around 30%-20km...
- Displayed charged is sometimes off by a lot. I turn it off an evening at 60% and it tells me 100% the next morning when i start it again. Sometimes the other way around I get off a public charger at 60% coming up from 12 and the next day at startup it states 12% again. Then 60 when i plug it
- Charge consumption is volatile : usually starting from 100% i'll get down to 90% in the first few kilometers before it start showing normal decrease. Sometimes on a level road at a stable speed i'll see 10% being used in 2km then i can do 10km within 2%.

Best moment is when 10km from my destination i have the 5% left alarm when the last time i did the exact same route i was able to finish fully with 15%. I then stopped thinking about my options and when restarting the scooter it gave a 12% reading so i was able to get to the destination no problem.
It also forgets my max charge setting, leading to me dropping the scooter at a public fast charger hoping to get a lot of battery back in a short period only to realize it forgot my 30amps setting and locked it back to 6amps.

Dealerships tried the firmware update and it did not change anything and they are not very helpful i'd say, honestly not sure they know what to do either.

 

[Bob66]

Hi Bestaflex, that behaviour sounds worrying.

I got my CE 04 right at the beginning back in April 2022 and have now done a shade over 8000 miles on it. Charging and discharging behaviour has been almost faultless. Each time the bike has had a service or new tyres it has had the latest software updates. I do most of my charging at home at 6A and when not in use try to keep state of charge in the range 60 to 80%. Once every few weeks I top it up to 100% just prior to a regular journey to avoid going below 20%. Occasionally, I have charged at 30A when trying to make quick progress on a long journey. I also avoid using and charging the battery at sub-zero ºC temperatures and very hot (for the UK) temperatures, say above about 30ºC. I haven't noticed any sudden drops in battery capacity from new. My only real complaints (niggles really) are that the predicted charging times at 6A are very conservative (it seems to charge way quicker than predicted) and when you hit an indicated 100% charge at 6A, it isn't really 100% since charging continues on for a considerable time, say another 15 to 30 minutes I guess. These comments only apply to 6A charging since I don't routinely charge at higher rates.

My point is that when working properly, the CE 04 battery and management system works very well and very reliably. It sounds to me like there is something wrong with your battery. Early model Zero SR/F and SR/S electric bikes had a similar problem whereby the charging system reported erratic SoC values resulting in, for example, the BMS reporting low SoC even after recent charging and then after switching off, waiting and then switching back on seemingly recovering a large state of charge. The community termed this "magic charging". I can't remember where I read it but one owner proposed that the issue was due to faulty (intermittent) connections between individual cells wired in series which resulted in fluctuation in battery voltage and hence SoC perceived by the BMS. Perhaps a similar fault exists with your battery. It's just a thought.

Regards

Bob

 

[Bestaflex]

Honestly my take is that there is a faulty calculator somewhere because i've searched the internet 3 times around and his post is the only one that talked about something even remotely close to what i have.

I have had the C-EVO from 2017-2022 before this one and never had any issues of the like with it. Range or charge was always on the dot and very predictable.

 

[Glengormley]

I’ve had similar issues from new. I don’t public charge but inaccuracies on range and battery capacity as you have described. Firmware updated with some improvements in the frequency of this. I am noting ambient temperature as I believe that it may have some baring on this. At least on my petrol bike I could shake it to ascertain if there is any fuel in the tank.
I just keep an idea in my head how many miles I have traveled since last charge. Capacity and range is as expected just the readings are erratic.

 

[Bestaflex]

I was at the dealership yesterday and they checked if there were default codes or mismatch between firmwares and nothing.
We will try a firmware full reinstall mid january and if that still doesn't work we'll move to a warranty call.
i'll keep you posted

 

[Tux]

I’ve had similar issues from new. I don’t public charge but inaccuracies on range and battery capacity as you have described. Firmware updated with some improvements in the frequency of this. I am noting ambient temperature as I believe that it may have some baring on this. At least on my petrol bike I could shake it to ascertain if there is any fuel in the tank.
I just keep an idea in my head how many miles I have traveled since last charge. Capacity and range is as expected just the readings are erratic.

I feel that either the LIM replacement or change in season has fixed the issue as my CE has been behaving recently. and looking back the issues was at its worst in the middle of winter. High speed under 5c was when the issue was most apparent, and when the garage temp was under 15c.
Will be able to confirm next winter.

 

[Tux]

Hi Bestaflex, that behaviour sounds worrying.

I got my CE 04 right at the beginning back in April 2022 and have now done a shade over 8000 miles on it. Charging and discharging behaviour has been almost faultless. Each time the bike has had a service or new tyres it has had the latest software updates. I do most of my charging at home at 6A and when not in use try to keep state of charge in the range 60 to 80%. Once every few weeks I top it up to 100% just prior to a regular journey to avoid going below 20%. Occasionally, I have charged at 30A when trying to make quick progress on a long journey. I also avoid using and charging the battery at sub-zero ºC temperatures and very hot (for the UK) temperatures, say above about 30ºC. I haven't noticed any sudden drops in battery capacity from new. My only real complaints (niggles really) are that the predicted charging times at 6A are very conservative (it seems to charge way quicker than predicted) and when you hit an indicated 100% charge at 6A, it isn't really 100% since charging continues on for a considerable time, say another 15 to 30 minutes I guess. These comments only apply to 6A charging since I don't routinely charge at higher rates.

My point is that when working properly, the CE 04 battery and management system works very well and very reliably. It sounds to me like there is something wrong with your battery. Early model Zero SR/F and SR/S electric bikes had a similar problem whereby the charging system reported erratic SoC values resulting in, for example, the BMS reporting low SoC even after recent charging and then after switching off, waiting and then switching back on seemingly recovering a large state of charge. The community termed this "magic charging". I can't remember where I read it but one owner proposed that the issue was due to faulty (intermittent) connections between individual cells wired in series which resulted in fluctuation in battery voltage and hence SoC perceived by the BMS. Perhaps a similar fault exists with your battery. It's just a thought.

Regards

Bob

Hey Bob Thank you for the explanation
Out of curiosity, How do you manage to charge from 60 to 80%, do you have a smart EVSE, or do you set a timer?

 

[Bob66]

Hey Bob Thank you for the explanation
Out of curiosity, How do you manage to charge from 60 to 80%, do you have a smart EVSE, or do you set a timer?

I just use a very simple count-down timer mains plug in tandem with the charging unit supplied with my bike. One press gives 15 minutes, another gives 30 minutes, another gives 45 minutes, another gives 1 hour and further presses give an extra hour per press right up to 9 hours. A different LED lights up for each time period selected which means there are no fussy digital displays to squint at in the semi-dark of my garage. I wouldn't be without it now.

 

[Mr EZ]

So I have had the issue since the temps dropped.

I start at 100 and one mile away I'm at 90, then it drops to 85%. It stays there for a while until it starts dropping normally.

I home charge at 30A.

I figured that it was the temp and the bike was warming top the battery.