JKBMS Inverter Edition Problems/Issues | No Support / Help to fix major issues. - DO NOT BUY ! Warning (as of Oct.12.2024)
- Thread starter Steve_S
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This needs to be done in order to overcome the voltage drop on the thick battery wires.
I did it the other way around, by calibrating on the inverter the battery voltage at 0.1V below the real calibrated BMS voltage.
Otherwise the RCV to trigger the timer is not reached.
I did it the other way around, by calibrating on the inverter the battery voltage at 0.1V below the real calibrated BMS voltage.
Otherwise the RCV to trigger the timer is not reached.
Sun in Lithium
Northwest Alberta Solar supplier/installer.
An easy way for jk to fix this is to have the 100% reset voltage. Start the timer.
Alright update on the whole.. Too much battery capacity for the BMs's to handle problem
Set all 3 BMS reported capacity at 1570ah or 2/3's of the actual capacity.
Previously the breaking point was when all 3 Bms's would reach 74% it would die. Now I had the communication overflow happen at 92%.
At overflow, the Inverter begins reporting 0% (while all 3 BMS's show correctly) which means it kills the power to the Backup (or my whole house to be exact).
So right now I'm thinking either reducing the reported capacity by half of it's whole capacity.. which would be.. 2354 / 2 = 1177.
But I can see that this is not ideal solution, as the reported capacity by the BMS's will reach 0% by the time the batteries are half discharged. So I'm a little bit lost on what to actually do :/
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rogerheflin
Solar Addict
A trick someone in another thread is doing (in their case adding another battery makes their inverter do weird crap). They have 12 batteries connected in the master/slave bms setup and connected to the inverter (#13 breaks the inverter) and they have 3-4 more batteries that are not part of the master slave but connected to the inverter DC power. Because of the way the bmses track current the extra unconnected batteries pretty much track the connected batteries. The only issue this could cause is if the unconnected battery significantly drifts away from the 2 connected batteries such that it does not fully charge and/or goes into protection. You would have to check the unconnected battery once in a while to make sure it is working right.
That indeed is an option and more or less will probably be my last resort due to few issues:
1. As you said, the BMS's don't communicate with each other on this Open loop, which means might be charge deviations (will test over time)
2. The inverter shows wrong battery charge (in kwh) if less batteries are connected. So it looks like this:
3 batteries in closed loop = 1kwh charge
2 batteries is 2/3 so = 0.66kwh
1 battery is 1/3 so = 0.33kwh
Charge reported and tracked by the Inverter. however all batteries do indeed get the charge, abeit unevenly if disconnected comms
If you search ghost battery perhaps this would help
I tried similar using a uno and a megga but they were too slow. I now use teensy's.
Teensy 4.1 Triple CAN Board with 240x240 LCD and Ethernet
This is a Teensy 4.1 board with triple CAN connections and ethernet magjack. Two CAN 2.0B and one CAN FD. It can be powered by an external +12v DC with reverse voltage protection. Included is also a 240x240 wide angle IPS TFT LCD display. Features Teensy 4.1 (installed) On board voltage...
www.skpang.co.uk
Alright I'm curious, what did you mean by too slow and how and why do you use Tennsy? (I honest to dirt know barely anything so please be patient and explain it like to a child)I tried similar using a uno and a megga but they were too slow. I now use teensy's.
Teensy 4.1 Triple CAN Board with 240x240 LCD and Ethernet
This is a Teensy 4.1 board with triple CAN connections and ethernet magjack. Two CAN 2.0B and one CAN FD. It can be powered by an external +12v DC with reverse voltage protection. Included is also a 240x240 wide angle IPS TFT LCD display. Features Teensy 4.1 (installed) On board voltage...
HarveyDent
New Member
SOC in JK BMS has never been and will never be counted correctly. The lower the SOC value, the bigger the difference. This is not changed by voltage calibration, amperage at high load, or other niggles.. Since I use YamBMS to control charging and send SOC 100% to my Deye inverter , all problems are over.
Compare SOC JKBMS 15.38 vs Victron SmartShunt
Compare SOC JKBMS 15.38 vs Victron SmartShunt
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I am actually planning to build up the YamBMS, though I'm bit confused on parts I need. I will however find a video of someone building eventually I suppose
Too slow, as in it wasn't fast enough to read all the CAN messages- ie it would miss some.
Strange problem with Deye 10k 3ph inverter and RFV Time transfering to float mode. Some days battery meets all the requirements that means SOC 100% voltage is met for RFV time 30 minutes, but battery and inverter does not change to float mode, it is like voltage command to inverter goes just a little bit before 100% battery reset which immidiately resets the timer and there is no float mode happening. First try 14:23, second try 14:53 - see 30 minutes.
Some days it works on first try others 1 or 2 tries. It does not have any extra negative impact, but it is super strange behaviour.
Some days it works on first try others 1 or 2 tries. It does not have any extra negative impact, but it is super strange behaviour.
are you using all the JK BMS + victron + Can to deye with only one Atom S3?
RCinFLA
Solar Wizard
- Joined
- Jun 21, 2020
- Messages
- 3,983
I do not like the 100% full trigger algorithm of the new 15.35 firmware.
If you have a random inverter load a little bit before BMS check for BatVol >= 100% SoC Full voltage the load will have dragged down the battery voltage below 100% full trigger and it will jump back into a full absorb period charging.
In my opinion this kills any chance of connecting inverter comm as the chance of repetitive Absorb cycles on battery is too great for my taste.
I run open loop with inverter/charger controlling the actual absorb time and I set the JK PB BMS RCV timer to a short period of time so step 2 has less of a vulnerable window for a random inverter load to drop battery below absorb voltage.
In the functions control screen, I disable float mode so steps 6 and 7 are not executed. My inverter/charger decides when to reinitiate a new full absorb charge cycle.
If you have a random inverter load a little bit before BMS check for BatVol >= 100% SoC Full voltage the load will have dragged down the battery voltage below 100% full trigger and it will jump back into a full absorb period charging.
In my opinion this kills any chance of connecting inverter comm as the chance of repetitive Absorb cycles on battery is too great for my taste.
I run open loop with inverter/charger controlling the actual absorb time and I set the JK PB BMS RCV timer to a short period of time so step 2 has less of a vulnerable window for a random inverter load to drop battery below absorb voltage.
In the functions control screen, I disable float mode so steps 6 and 7 are not executed. My inverter/charger decides when to reinitiate a new full absorb charge cycle.
RCinFLA
Solar Wizard
- Joined
- Jun 21, 2020
- Messages
- 3,983
With no inverter communications, set short RCV timer in BMS and let inverter/charger determine actual absorb time.
If you have inverter communication with BMS, a short RCV timer will also cause a short absorb time.
Don't forget to disable float mode in BMS on function enable/disable screen.
Float period (or more specifically how long before it starts a new full charge absorb cycle) should not just be timer determined. It should also use battery voltage in decision to initiate a new recharge cycle. If you are away on vacation, drawing very little power from battery, do you want it pounding a new absorb level full recharge every time float timer expires?
Recharge timers are useful on PV based recharging where you need to trigger charging during daylight or lose the opportunity to get some recharging.
HarveyDent
New Member
Yes, I confirm
Could someone take a look at my settings and let me know what should/needs to be changed, for some reason they never get 100%, they stop charging just short of 100% soc voltage. Here is a screen shot of the master battery and one of the slave ones. They are closed loop with my eg4 6000xp inverters.
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Sun in Lithium
Northwest Alberta Solar supplier/installer.
I noticed this as well. With the 12000xp. The ik bms needs to reach the RCV before it starts the absorption timer. But the inverter uses it's own internal voltage measurement. And never gets the battery to the RCV. The only way I got the battery to work is to calibrate the bms voltage to read a bit higher. So the absorption timer starts.
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How did you do that?