Interesting observation about CCS Setec adapter and losing range

[SteelClouds]

I have both a Tesla Chad adapter and a SETEC CCS Adapter for my Model 3. Due some circumstances, I have been charging almost exclusively using the SETEC for the past 45 days.. over 600 Kw worth . Has not missed a beat. Here is the interesting thing. I use teslaapp to monitor different things. See that gap from 16500 miles to 18500 or so? ( according to my log, its about 1800 miles for the month and half) Thats all the SETEC charging.. The dots are my normal mobile charger or supercharging. Or as it turns out the Chad adapter. The SETEC is not tracked for some reason.. I think it is because the SETEC throws an error every time I use it about a dangerous spark condition.

The important thing is my range dropped from 215 @100% to about 205@100%. I ended going back to my mobile charger and a few super charges to reset the battery computer and watch the range crawl back to 215@100%/ That took a couple of weeks of "therapy".

The hypothetical thought is the SETEC charger confuses the BCM if used for an extended period of time. Obviously something happens since the app cant track the SOC when it's used. But it will pick up the Telsa Chad adapter when used.

I wouldnt care much but with short legs ( 2019 STD+), every mile counts . I will admit that 600Kw of use for the SETEC is probably a lot more than most do in the time they own theirs before they sell it .

Fun stuff

 

[Boeingpilot]

Interesting.

 

[ElectricIAC]

I think exclusive DCFC usage tends to make the BMS drift.

 

[electric-donut]

You need to find access to a level 2 charger. Perform a search for "battery degradation reversal". Procedures are documented to allow the BMS to recalibrate the batteries. Typically lowering charge to <10%, leave sit for a few hours, level 2 charge to 100%. There may be a few more steps, so take the time and do the research.

 

[SteelClouds]

You need to find access to a level 2 charger. Perform a search for "battery degradation reversal". Procedures are documented to allow the BMS to recalibrate the batteries. Typically lowering charge to <10%, leave sit for a few hours, level 2 charge to 100%. There may be a few more steps, so take the time and do the research.

Yeah.. been there done that.. Gone back to 216 miles. I have to do this about every 6 months. I had to do this when I first got the car since it was used and had been sitting for a few months.

 

[electric-donut]

I just bought my used 2018 MS-100D last week. I think I got lucky. Even though the car has 21's, it still calculates out to 290 miles @ 50K miles. I will try to recalibrate after I get my level 2 charger working to see if it makes a difference.

One thread I read stated as long as the SOC was below 50%, it would stay balanced. Not sure I buy into that thought, but I will give it a try. I don't drive more than 40 miles a day, so I can keep it charged to 50% for a while to see how it responds.

I suspect the BMS actually starts performing a bottom balance when SOC gets down to single digits. Then when you take it up to 100%, it does a top balance. I think that's how max range gets recovered. Time will tell.

Will Prowse over at DIY Solar knows a lot about lithium charge characteristics. He has done a lot with lithium batteries on the solar side, as well as having several EVs. I think the basic concepts are similar, if not the same. Since the BMS is "proprietary to Tesla, I would be surprised if they didn't incorporate that into the BMS logic, since they warranty the battery. The criteria is likely based on providing a mechanism to maximize usable capacity. In Tesla fashion, I can understand why they wouldn't publicize it, for proprietary reasons. Once it becomes common industry knowledge, they will probably acknowledge what they do to keep range maximized. Until then, we will be treated like mushrooms and left to our own devices.

 

[Big Earl]

This is normal and to be expected. I agree with @ElectricIAC that exclusive DC charging can cause the BMS to drift - at least in my experiences where I DC fast charge for extended periods on road trips. It's honestly inconsequential - being off by five or ten miles has no real-world impact on daily life. You should also expect range degradation over time regardless of whether you fast charge or L2 charge.