I changed out my seplos today for a JK, the battery was already at 100% SOC when I removed the solis.

The problem now is, the JK seems to be stuck on 70% SOC.

I have used the settings from offgridgarage.

What I have tried.

• Triggering a over charge alarm, whilst the app stated the battery is fully charged (yellow warning text), it didn't change the SOC.

• All cells are over the 100% v setting

Any suggestions? What am I missing?

Start by charging to 3.45v per cell and let the cells fully absord till the amps drop to about 2A then increase the voltage to 3.475 and let it absorb again till amps drop down, keep repeating increasing by 0.025 till you get all the cells nicely top balanced at 3.65v. Takes a while to do this but seriously worth the effort.
Then reset the bms and set all your preferred settings, (Andy gives some good settings to use).
Now do a full discharge and then charge back to top, SOC should then correctly give you 100% at the top setting you choose.

49 minutes ago, WannabeSolarSparky said:

Start by charging to 3.45v per cell and let the cells fully absord till the amps drop to about 2A then increase the voltage to 3.475 and let it absorb again till amps drop down, keep repeating increasing by 0.025 till you get all the cells nicely top balanced at 3.65v. Takes a while to do this but seriously worth the effort.
Then reset the bms and set all your preferred settings, (Andy gives some good settings to use).
Now do a full discharge and then charge back to top, SOC should then correctly give you 100% at the top setting you choose.

Thanks, will give this a try.

I do have a sneaky suspicion that I might have skrewed up the calibration for the specific bms, I have ordered a better multimeter (with clamp) that will arrive tomorrow.

Will report back if this resolves it, but might take a day or 2 to fully discharge.

12 hours ago, Pho3niX90 said:

Thanks, will give this a try.

I do have a sneaky suspicion that I might have skrewed up the calibration for the specific bms, I have ordered a better multimeter (with clamp) that will arrive tomorrow.

Will report back if this resolves it, but might take a day or 2 to fully discharge.

Just to add a point. Even if the reading(calibration) is out it will be the same for all cells. Rather get the balancing sorted out as @WannabeSolarSparky indicated in his post. The finer detail like calibration can be done later. Even calibrating at 3.35V could be out by the time it reads 3.65V. My experience with a JK.

2 hours ago, Scorp007 said:

Just to add a point. Even if the reading(calibration) is out it will be the same for all cells. Rather get the balancing sorted out as @WannabeSolarSparky indicated in his post. The finer detail like calibration can be done later. Even calibrating at 3.35V could be out by the time it reads 3.65V. My experience with a JK.

The balancing itself is perfect, all cells are balanced to 4mv of eachother.

What annoys me, is that it acts as if it knows the pack is at 100%, but doesn't reset the actual SOC to 100% even if all cells are above the 100% cell setting (3.49).

In regards to the calibration, it's done now. The problem was that there are 3 packs connected to a busbar, 2 act OK, only the one which was prior on 100% isn't resetting. the other 2 packs were at 50%, and the default JK SOC was 60%, so it kepts charging them even when it reached 99%. Granted, they also never reset to 100%, but 99% is close enough.

Here are the 3 packs:

Pack 1: 72% today, it's actually fully charged, and the BMS is actually treating it as such. 4mv delta

Pack 2/3: Still new, still top balancing, but the SOC is closer @ 99%, 130mv/160mv delta

Here is a better example. This is for the battery not resetting to 100% soc

and my settings match these, except RCV is set to 3.49, after reading on some forum the suggested variance between it and 100% setting, should be 0.04

Ok, I seem to have found the issue. Found the following:

credit: original post

My RCV Timer was set to 5 hours, instead of 1 hour. After changing it, it went to 100% SOC