Two Thinks in Finland

[worry]

Hi,
Here's a reading of what you asked for. Taken while charging/balancing.

[Zuikkis]

OK! 1530 is roughly in the same area as my 1241, only slightly better. Thanks for the info, now I know what is my target.

[Marsto]

This is mine with all kinds of communication problems starting with high voltage errors and now after a month dried up a little and have CAN communication problems. Sometimes I am able to connect and sometimes not. I don`t know today how many faults exists but have no red triangle indicating HV faults which was present a month ago.

[Zuikkis]

Funny, same 1241KOhms as mine .. maybe it's indeed some "good enough" indicator, not real value?

When car was charging, the value wandered wildly. But when idle it's always 1241.

[Marsto]

Funny, same 1241KOhms as mine .. maybe it's indeed some "good enough" indicator, not real value?

When car was charging, the value wandered wildly. But when idle it's always 1241.

Yes, I think you are into something here. Lets hope more people will post their results.

[Zuikkis]

I got my tester now. I measured the insulation directly from heater connector.



Interestingly, there is absolutely no leak when car is powered off. Meter shows >550Mohm which is the maximum it can show. It is the same result when measuring either + to ground or - to ground.

Then I got brave and powered the car so battery is added to equation (and obviously there's now live 400V in the wires). The meter does seem to have slight issue with circuit being live, as it refuses to measure if it sees any negative voltage in the wires. But with + and - polarity correct, it measures about 10Mohm.

So in conclusion I'm now pretty sure the moisture is inside the battery.

However, car now did work fine, and I also charged without issues. Looking at CHAS, the reported isolation resistance while charging is now well above 2Mohm.

I think it is because of cold weather, it has been below 0C for whole week here so any liquid water must have frozen. I'll wait for warmer weather and test again.

[Marsto]

I have looked at the user data values from time to time and enclose a couple of pictures from March 14 and today. All values taken when car is idle. In between these days the car have dried up enough to be able to charge and start as normal. The car is fully drivable now with no present error codes. Interesting to see how much higher the Ohms are when the car is in fully working order. 

[Warlock]

 

Veldig fint å se at bien din tørker opp her altså
Om det er som vi antar, at sensoren er "good enough" og ikke nøyaktig kan faktisk høyere spenning alene også være med må å endre på denne verdien, jeg ser du har fått ladet opp bilen ca 40V mer 

[Marsto]

Here is another reading today april 7 2024 and the kOhms keep rising up. This is a screenshot taken from coomtool with fully charged battery and just with the ignition on. The car is now fully drivable but have stayed in the garage and dried up even more. I wonder how high the kOhms will get? 

[Zuikkis]

Same here, car sits in the garage and Kohms keep getting higher and higher. I assume it's fully operational now, but I'll wait a bit for the roads to dry.

If I ever drop the battery, I think it would be great idea to remove all HV cables, and then use my insulation meter to check resistance between battery module - and the casing.. this should show which module in is leaking.

Last year when I fixed the battery, I only disassembled modules that had bad cells that needed replacing.. It's possible there was moisture somewhere even if the voltages showed correct.

[Marsto]

Same here, car sits in the garage and Kohms keep getting higher and higher. I assume it's fully operational now, but I'll wait a bit for the roads to dry.

If I ever drop the battery, I think it would be great idea to remove all HV cables, and then use my insulation meter to check resistance between battery module - and the casing.. this should show which module in is leaking.

Last year when I fixed the battery, I only disassembled modules that had bad cells that needed replacing.. It's possible there was moisture somewhere even if the voltages showed correct.

Great. If you ever drop the battery it would be extremely important to make a procedure for how the resistance messure is done followed up with pictures. Here in Trondheim I believe it is now time to do a testdrive to check if the whole HV system is back to normal.

[Zuikkis]

I test drove the car today with Commtool running..

Initial KOhms were 2300K, but it kept dropping when I was driving. Eventually it was 1060K, which is quite bad if the "legal limit" is 1000K.

However the car drove fine, no issues.

[Zuikkis]

Last night I charged the car to 100%, then drove to work today (about 20km). Now ohms were 2300K for most of the drive, but just dropped to 1800K when I was at work. Apparently the charging had dried the battery?

I hope it's ok now.

[Marsto]

Last night I charged the car to 100%, then drove to work today (about 20km). Now ohms were 2300K for most of the drive, but just dropped to 1800K when I was at work. Apparently the charging had dried the battery?

I hope it's ok now.

Very promising development. I will try the same as you soon to see what happens to the KOhms in commtool.

[Zuikkis]

sigh... back to square one. Broken RLEC cards again, I'm not sure if I have enough left..

I think it should be possible to combine the two 400V strings into one. Connect two modules in parallel and let single RLEC take care of two modules, just what I did in my home energy storage. Or perhaps it's now time to design my own "RLEC clone" card..

Edit: Oh just noticed in another thread that there's still new RLECs available..

Just need to do it properly this time. I'm not sure if there's still a hole that lets water in, or is there some old water inside battery modules? Last year I only disassembled modules that had weak cells (voltage under 2V), perhaps they need to be all teared down and make sure they are dry..