JK-B1A24S / JK-B2A24S Active Balancer

not2bme

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Joined
Oct 16, 2017
Messages
490
I don't think jblance's program does any programming. I can't remember, but doesn't the default app have provisions to set a voltage? I thought there's a low voltage setting where it will stop balancing once it reaches a low voltage limit. So you can set it to 4.0V so it will never balance until it gets over that value. Oh I just noticed that you have the BMS version, which may have a different interface?

But is it necessary to limit at such a high voltage? I know I set the deviation voltage to about 0.05V (50mV) before it starts to balance (if it ever gets over 50mV, which in my case is quite rare) since it's never burning off the energy but transferring to another pack, therefore I'm not losing any energy (other than the slight losses when transferring). That's the advantage of the active balancing so it's not balancing only when it reaches the top which if you were to do so on a passive balancer it will burning off energy, therefore is best only when you reach the top when you have excess energy to burn.
 

Walde

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May 18, 2018
Messages
120
I don't think jblance's program does any programming. I can't remember, but doesn't the default app have provisions to set a voltage? I thought there's a low voltage setting where it will stop balancing once it reaches a low voltage limit. So you can set it to 4.0V so it will never balance until it gets over that value. Oh I just noticed that you have the BMS version, which may have a different interface?

Unfortunately in the setting I only get it to switch off automatically only to 3.2V every input above it is set to 3.2V inputs to 3.1 3.0 2.9 2.8 also work. Which model do you have and which software do you use for it. Greetings Dirk
 

sshoecraft

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Jan 23, 2021
Messages
46
Let's hear how you do it, I'm definitely not the only one who's interested. Greetings Dirk

"I have found NO WAY ..." Or, in other words, I can't do it.

The protocol for the UART is exactly the same as the JBD (maybe they all share the same base firmware code) but without the ability to enter eeprom mode, I can't write to the registers (which aren't published by jikong).

You could maybe write a bluetooth service which presents itself as a JK bms, then proxies the commands to the BMS so you can see all the commands the cell phone app is sending.

I have since dropped use of this bms in my powerwall and use the JBD with a seperate active balancer (together they are nearly 1/2 the cost of the JK).
 

not2bme

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Joined
Oct 16, 2017
Messages
490
There's a RS485 protocol that will turn the balancer on or off. I've just never tried it. The script I use would probably be able to produce that, since the call to it is the same, so if you're handy with looking at code, you could possibly figure out the place where it calls for the get information and swap it with the one for turning on/off.

jkbms-onoff.PNG

The above shows the code to turn it on. (oh this is for the jk-b1a24s balancer only board. I'm assuming it's the same command code for the BMS version)
 

sshoecraft

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Joined
Jan 23, 2021
Messages
46
Unfortunately the balancer commands are not the same as the BMS ones; as I learned early on.

I've scanned all the registers on the BMS (from 0 to 255) and only 3,4,5, and 6 respond.

I had hoped that writing to register F6 would work, but alas, no joy.
 

sshoecraft

Member
Joined
Jan 23, 2021
Messages
46
I have the JK-B2A16S for my 14 pack system.

Is it possible to control the JK via Blutooth from Rasspery.
I would like to switch the balancer on automatically at over 4Volt (56Volt package) and switch it off again when the voltages drop below 4Volt in the evening and at night. does someone already have a script running with the https://github.com/jblance/jkbms system. Greetings Dirk

I'm not able to make any configuration changes to the BMS at this time. I looked at jkbms source code and I dont see where he can turn balance on/off.

Looking at the bluetooth app, there is a setting under "Max Balance Cur." called "Start Balance Volt." which may be what you want. Set that to 4.0 and see if that does what you want.
 
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