YamBMS JK-BMS-CAN with new Cut-Off Charging Logic (open-source)

[silverstone]

Flashing back to old - to save myself money today

Don't know your weather but here it's so cloudly, foggy and started snowing that the inverter is barely producing anything from PV ...

 

[MrPablo]

I tend to agree. Except at the top of the charge curve in my case, one cell rises quite fast (3.55V -> 3.60V in less than 5s).
Hence my reccomendation to lower the update_interval to 1s. 3s might also be enough.

The "overhead" of the mqtt is peanuts compared to the "delay" that could be caused by update_interval on the esp32

The auto current control should keep that situation under control, even at 5s. If you look at the beginning of the thread, I posted a link to a Google sheet - it shows how max current will taper off in advance of OVPR.

 

[chaosnature]

There should be some additional fields in the diagnostic section as well.

this connected and disconnected would be when i was flashing over with new/old code

 

[chaosnature]

There should be some additional fields in the diagnostic section as well.

No more..

 

[silverstone]

The auto current control should keep that situation under control, even at 5s. If you look at the beginning of the thread, I posted a link to a Google sheet - it shows how max current will taper off in advance of OVPR.

But is that already implemented in @Der_Hannes code ? Or is this in the newly upcoming version ?

 

[MrPablo]

But is that already implemented in @Der_Hannes code ? Or is this in the newly upcoming version ?

That's already in v1.17.3 which has been released for a little while - I think I saw @Der_Hannes said it was part of his code too.

 

[silverstone]

That's already in v1.17.3 which has been released for a little while - I think I saw @Der_Hannes said it was part of his code too.

OK so I got a bit lost in what v1.17.4 introduced new.

 

[Der_Hannes]

mainly v1.17.4 will also lower the charge voltage in addition to the charge current
@MrPablo please correct me if i´m wrong

 

[MrPablo]

View attachment 201234
View attachment 201235
View attachment 201236
this connected and disconnected would be when i was flashing over with new/old code

View attachment 201237

Ok, I think I've identified the problem.
I suggest staying on the old firmware for today, I'll provide a YAML for you to test tomorrow.

Edit:
For others, please note this issue only affects li-ion batteries, any LFP batteries will work as normal.

 

[silverstone]

mainly v1.17.4 will also lower the charge voltage in addition to the charge current
@MrPablo please correct me if i´m wrong

Just to make sure: are these "reference" values for the inverter also accessible via e.g. MQTT ?

I'd like to also set my charger to the same reference values (I have a charger in parallel with the batteries, but the charger setpoint must be approx. 0.1V BELOW the inverter, otherwise the inverter will forcefully try to discharge the batteries, totally ignoring the batteries).

 

[MrPablo]

mainly v1.17.4 will also lower the charge voltage in addition to the charge current
@MrPablo please correct me if i´m wrong

Yes, that's the main feature alongside a few minor enhancements and tweaks.

 

[Der_Hannes]

Just to make sure: are these "reference" values for the inverter also accessible via e.g. MQTT ?

I'd like to also set my charger to the same reference values (I have a charger in parallel with the batteries, but the charger setpoint must be approx. 0.1V BELOW the inverter, otherwise the inverter will forcefully try to discharge the batteries, totally ignoring the batteries).

on my repo for sure - its the requested charge voltage

 

[chaosnature]

Ok, I think I've identified the problem.
I suggest staying on the old firmware for today, I'll provide a YAML for you to test tomorrow.

Edit:
For others, please note this issue only affects li-ion batteries, any LFP batteries will work as normal.

No worries

 

[chaosnature]

Ok, I think I've identified the problem.
I suggest staying on the old firmware for today, I'll provide a YAML for you to test tomorrow.

Edit:
For others, please note this issue only affects li-ion batteries, any LFP batteries will work as normal.

lol...glad you have...that problem stressed me out yesterday - what didn't help was my toothache I had to also contend with

 

[chaosnature]

Hey MrPablo.

I know it's early, but did you get around to making the update for the Lithium setup?

thanks

 

[MrPablo]

Hey MrPablo.

I know it's early, but did you get around to making the update for the Lithium setup?

thanks

Can you send screenshots of all the settings values as shown in the JK BMS app?

 

[chaosnature]

Can you send screenshots of all the settings values as shown in the JK BMS app?

Here you go...

 

[MrPablo]

Some of the values shown on your earlier HA screenshot don't seem to quite line up with the BMS values.
Could you confirm exactly what the full sensor name is for the below sensors?

The reason I ask is because the UVPR value is used for determining auto discharge current values.

 

[ChrisG]

Have to say that version 1.17.3 is working perfectly for my EG4 6000xp (LFP Battery Type 2). Charging slowly at the moment for additional testing/calibration readings. Forgot the charge limit can only be updated by reflashing so will need to edit the config and update again.

 

[chaosnature]

Some of the values shown on your earlier HA screenshot don't seem to quite line up with the BMS values.
Could you confirm exactly what the full sensor name is for the below sensors?

The reason I ask is because the UVPR value is used for determining auto discharge current values.
View attachment 201439

remember i am running old version on master and new on slave - so you want to look at the master version of ESP which i think is the screenshot i provided

 

[chaosnature]

of the values shown on your earlier HA screenshot don't seem to quite line up with the BMS values.
Could you confirm exactly what the full sensor name is for the below sensors?

The reason I ask is because the UVPR value is used for determining auto discharge current values.
View attachment 201439

jk-bms-ble-can-2 cell voltage undervoltage protection - 3.33
jk-bms-ble-can-2 cell voltage undervoltage recovery - 4.0 i think

 

[chaosnature]

jk-bms-ble-can-2 cell voltage undervoltage protection - 3.33
jk-bms-ble-can-2 cell voltage undervoltage recovery - 40 i think

that could be the issue - would it be trying to recover from 4.0 ?
That would be too high

 

[silverstone]

jk-bms-ble-can-2 cell voltage undervoltage protection - 3.33
jk-bms-ble-can-2 cell voltage undervoltage recovery - 40 i think

40 ??????

 

[silverstone]

that could be the issue - would it be trying to recover from 4.0 ?

UNDERvoltage Recovery must be > UNDERvoltage Protection but you'll never recover like that !

 

[chaosnature]

40 ??????

Typo corrected