Battery health test

[jyavenard]

So I'm running it on mine.

I started with 20%. It went down to 8% and then stayed there for about 2 hours. After that it started charging.

The test was only using about 6kW to discharge the battery, having a 2019 model 3 with a resistive heater, I also started the heater to max temperature to speed things up a bit; it drew over 13kW at one stage. At 12% I stopped the heater and let the car proceed normally.

My battery was showing a nominal full pack of 68.3kWh at 50%; at 12% SoC it dropped to 67.9kWh.

Edit: my bad, didn't realise this was a model Y forum.

 

[Mrbrock]

So I'm running it on mine.

I started with 20%. It went down to 8% and then stayed there for about 2 hours. After that it started charging.

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The test was only using about 6kW to discharge the battery, having a 2019 model 3 with a resistive heater, I also started the heater to max temperature to speed things up a bit; it drew over 13kW at one stage. At 12% I stopped the heater and let the car proceed normally.

My battery was showing a nominal full pack of 68.3kWh at 50%; at 12% SoC it dropped to 67.9kWh.

Edit: my bad, didn't realise this was a model Y forum.

Interesting data to me is you’ve added 12,600kwh via AC/DC charging and regen but only used 7200kwh for driving. In pretty much every last discussion on efficiency I’ve seen, people only discuss amount used vs amount added via a cord. in your case 9600kwh added vs 7200kwh used or 75% (some of this is normal charging loss but some is non driving use). That sounds pretty good but the actual is more like 57%.

 

[MP3Mike]

Interesting data to me is you’ve added 12,600kwh via AC/DC charging and regen but only used 7200kwh for driving. In pretty much every last discussion on efficiency I’ve seen, people only discuss amount used vs amount added via a cord. in your case 9600kwh added vs 7200kwh used or 75% (some of this is normal charging loss but some is non driving use). That sounds pretty good but the actual is more like 57%.

I don't think use when sitting in Park is counted in those numbers. For example, Sentry usage, cabin overheat protection, dog mode, etc. all of which can add up quick.

 

[Mrbrock]

I don't think use when sitting in Park is counted in those numbers. For example, Sentry usage, cabin overheat protection, dog mode, etc. all of which can add up quick.

Exactly my point. There is a lot of inefficiency that goes unreported.

 

[vinnie97]

I tried this on a 2018 long range model 3. I got the power down to zero percent using the heater, but after at least 5 hours progressed and no charging initiated, I canceled it and started to charge it back up manually myself.

 

[Mrbrock]

I tried this on a 2018 long range model 3. I got the power down to zero percent using the heater, but after at least 5 hours progressed and no charging initiated, I canceled it and started to charge it back up manually myself.

It probably needed to be higher than zero so it had some usage data for the calculation.

 

[speedyranger74]

I tried this on a 2018 long range model 3. I got the power down to zero percent using the heater, but after at least 5 hours progressed and no charging initiated, I canceled it and started to charge it back up manually myself.

I make the same mistake. Have to be more than 5%.

 

[vinnie97]

I make the same mistake. Have to be more than 5%.

I started at 7% or 8% actually. I just turned on the heater to encourage it along. I don't think I'll try it again so as to not waste another cycle.

 

[jyavenard]

Did it again, now that 2023.6 makes it easy to enter service mode (no more geofencing). Came back with 91% and scan my tesla gives me 68.4kWh.
Interesting that Tesla seems to use 75kWh as basis for calculating the degradation, rather than the "initial battery capacity" shown in Scan My Tesla (77.8kWh)

 

[speedyranger74]

I have a doubt: GTW LOCKED.
Even it show " Test in progress " seem don't want to start to charge.
Stopped to waste battery at SOC: 8.1% - one hour ago.
I'm not sure if will start charging!?
Any hint?
Thank you.

 

[jyavenard]

I have a doubt: GTW LOCKED.
Even it show " Test in progress " seem don't want to start to charge.
Stopped to waste battery at SOC: 8.1% - one hour ago.
I'm not sure if will start charging!?
Any hint?
Thank you.

It needs to take the battery down to zero before it attempts to charge again. That will take a couple of hours.

Of course it won’t start charging with a SoC of 8.1%

 

[israndy]

Has anyone tried this test using a public FREE charger? At home I try to only use solar to charge the Tesla, so it takes a couple of days. Am I just too cheap?

 

[MP3Mike]

Has anyone tried this test using a public FREE charger? At home I try to only use solar to charge the Tesla, so it takes a couple of days. Am I just too cheap?

As long as the charger is AC, >=6kW, and will stay active while the battery is discharged it should work. But the test as a whole takes ~20 hours, so I don't think using a public charger is really appropriate.

You can see an Out of Spec video where they recently tested a Hertz Model Y:

 

[speedyranger74]

It needs to take the battery down to zero before it attempts to charge again. That will take a couple of hours.

Of course it won’t start charging with a SoC of 8.1%

Any way the final conclusion: test battery failed again.
Didn’t start even below 0%... maybe because I was in the car?

 

[jyavenard]

Any way the final conclusion: test battery failed again.
Didn’t start even below 0%... maybe because I was in the car?

Yeah, last time it failed as I kept going into the car to check the progress.
This time I let it do its thing and only came once I knew the car had finished charging and the wall charger no longer showed any activity.

 

[rreinha]

I did the Service Mode: Battery Health Test a few times this week without success. I had an VCFRONT_a135_coolantLevelLow alert and this was causing the the health test would stall at 20% after several hours. If the fans do not come on with with more than 8% SOC check the alerts and thermo performance test.
VCFRONT_a135_coolantLevelLow alert also cause the thermo performance test to fail with a low coolant fault .
I added 6 ozs of Zerek G48 blue coolant on the radiator reservoir..
After adding the coolant Reran the battery test, the Fans came on and the test ran without an issue Started at 24%, with fans on high, fans ran until 8% battery drained to 1% before charging started and charged to 100%
Added 50kWh to the pack and report say 82%????? this is a M3 LR AWD with 95K miles on it My calc say 63% but Tesla must be using 59kWh as their Pack sizes.
I was also having Charger issues with it stopping charges before completing and this was over the last few months, this problem is not corrected as well.

 

[BakerBug]

Hello everyone!

I've got a 2020 MY LR (2023.7.20) with 46k miles on it. I just ran the battery self test, and it completed without showing a percentage result. It still had the --% displayed.

I'm wondering if there is a timeout for the test that I may have inadvertently run into. I started the test around 8AM with about 40% SoC. The battery drained to 5% and then sat there for several hours. The curious thing is that exactly at 10PM it started charging, which is when I normally have it scheduled to begin.

The next morning I checked around 7AM and the SoC was 100% with the test still running. I came back later, 10AM? and the test had completed but the result was --%.

Has anyone else run into this? I'll try running the test again next week and disable my scheduled charging.

 

[Pianewman]

It sounds like your scheduled charging interrupted the test. Yes, disable the scheduled charging and run the test again.

I would do the test after you've run the battery down to 5%, but that's just me. Good luck.

 

[Marsh25]

Been setting at 49% for the past 70 minutes. Not sure if this is a pause during the test, or if I've messed up by not setting charge level to 100% before starting the test.

I'm trying this on a used model 3. Plugged it in at work and the app shows it stopped charging at 56%. It's been about 16hts since starting. Anyone else experience this and still have success! There is very very little info on this test online.

 

[JonB65]

I'm trying this on a used model 3. Plugged it in at work and the app shows it stopped charging at 56%. It's been about 16hts since starting. Anyone else experience this and still have success! There is very very little info on this test online.

I just went back and tried to remember what I did. I think I just left it and it eventually went to 100%. I'd suggest leaving it as is for a while and seeing what happens.