JKBMS

insular1 · 10-11-2023 2:29pm #1

Hi all,

Finally got my battery set up and running thanks to all the help I got on here. Figured I'd set up a new thread for the JKBMS as I don't see a dedicated one but the Seplos thread has been very useful.

In my set up I originally used the older JK-B2A20S20P-H-C which doesn't communicate with the inverter. I set it up in parallel with my current Weco batteries and just let them communicate with the inverter and it worked without issue. Wasn't a particularly optimised solution but that BMS was always planned to be short term as that BMS was an impulse buy from a fellow boardsie so I could get my cells up and running while waiting on the newer JKBMS to arrive from Hankzor store on aliexpress. Delivery was a little slower than expected but finally this week my JK-PB1A16S15P with inbuilt inverter communication arrived.

The following two videos from Off-Grid Garage made set up very straight forward:

https://www.youtube.com/watch?v=GNxn2SakirQ

https://www.youtube.com/watch?v=hmLcj1X89Dc&t=2015s

However as you can see in the video there appear to be some issues with these BMS hopefully can be fixed via software update.

I got the BMS up and running without issue however the CAN communication piece has been a pain. Took me a while of troubleshooting to get it to connect at all. Eventually through trial and error got the connection working but after a few seconds the Solis inverter gives a “BatName-Fail” error. From the Solis manual this error means the battery model does not match the selected model on the inverter however I have selected Pylon LV on both BMS and inverter so not sure what the error is. Went back to paralleling with the Weco and just letting the Weco do the communication with the inverter but this is only a short term solution as I plan to sell the Weco to fund further DIY expansion.

When I google the issue one of the first hits is actually the Seplos thread where @E30M3 appears to have had a similar issue with the Seplos. Wondering if anyone can shed some light on possible solutions? I have contacted Hankzor and am awaiting response. Anyone know a direct contact for JKBMS?

If not I’ll just have to wait on the OffGridGarage follow up video where hopefully he manages to sort the issue!

graememk · 10-11-2023 2:58pm

Use the user defined battery setting to get around the batt name fail. (Aobo sometimes works too)

insular1 · 10-11-2023 5:01pm

Yeah I tried Aobo but didn't work. Will have a look at the user defined settings tonight. Thanks for the tip.

Shame it doesn't work as advertised but hopefully a software update will sort it. Still very easy BMS to get up and running and the app is very straightforward. Now to figure out a way to get WiFi monitoring.

irishchris · 15-11-2023 9:57am

https://www.boards.ie/discussion/2058322007/jkbms

Following your progress with interest as have the 150a version of the same model ordered and on the way.

Hoping may have better joy with the sofar hybrid but not much info online on this bms version yet

insular1 · 15-11-2023 12:08pm

Haven't had a chance to try the user defined settings yet as have been busy and the battery is working away. I'm assuming it's not working as well as it would be if communicating directly with the inverter but it's charging and discharging correctly and saving me money so happy enough at present. Will hopefully have some time to mess with settings more tomorrow.

I did see on YouTube however that Off Grid Garage has given up on this BMS for now as JKBMS are not making all his suggested changes. Have a read of his latest post for more info. I'm still hopeful I'll be able to get mine working. I only want a very basic set up anyway so not requiring the level of control he seems to be looking for.

insular1 · 16-11-2023 9:42am

Got 10 minutes last night to mess around with the User Defined settings as suggested by @graememk above and it worked without issue. No failures at all. Appears to be charging and discharging correctly and inverter is reading the correct SOC from the BMS. I don't seem to be getting any of the issues Off Grid Garage was, but he was likely looking for functionality I don't really need. I'll do some more testing over the next few days to see if it's missing anything. Now I have to figure out what the optimal User Defined settings are!

I have a second battery built with another of these BMS so I also need to test how the RS485 communication works between them. Haven't tried that at all yet.

graememk · 16-11-2023 10:35am

One of the things that Andy was looking for was a setting in the BMS to automatically set the battery to 100%

From taking to other people the previous jk set it to 100% when one cell hit over voltage protection or something (eg 3.65v)

A better way would be when the pack voltage reaches a set voltage and current is low (eg 56-58v, 1amp).

insular1 · 16-11-2023 11:12am

I need to rewatch that video to see exactly what isn't working. My cells seem to be well matched and with the active balancing of the JKBMS I haven't seen them more than 3mV apart, so hoping this won't have much of an impact overall. Im just glad it's working and has been relatively painless in terms of set up time!

I am trying to figure out the best settings for the User Defined battery on the Solis. Any good source for this? I'm particularly unsure of what the float and equalising voltage settings and finding loads of different answers online.

insular1 · 17-11-2023 3:35pm

So did some more testing last night with the User Defined settings and from what I can see it all appears to be working perfectly. The settings I am using are below:

Battery Capacity: 300Ah (I have 300Ah cells)

Battery OVV_Pro: 58.2V (Just below the cell OVPR of 3.64V)

Battery UNV_Pro: 42.5V (Matching the Cell UVPR of 2.65V)

Floating voltage: 55.2V (Matching the BMS active balance voltage of 3.45V)

Equalizing Voltage: 55.2V (From my understanding equalizing is unnecessary for Lifpo4 so I just set it to the floating voltage)

Overcharge SOC: 100%

Overdischarge SOC: 15% (Might adjust this down to 10% in future after some testing)

Discharge depth: 80% (Not really sure the purpose of this. My understanding is that the overcharge and overdischarge settings above will limit how high/low the inverter will take the batteries SOC so I am unsure if this setting would really have any impact?)

I_Max Discharge: 100.0A (Max Solis can do)

I_Max Charge: 100.0A (Max setting)

Floating Current: 03:0A (No clue what this should be so left it on default)

Floating Time: 030mins (Again just left it on default)

Equalizing Time: 000day (Apparently unnecessary for lifepo4 so left it on 000)

Charge OVV_Pro: 60.0V (Was unsure exactly what this setting was but I interpreted as a max voltage the inverter would allow while charging. It was set at default at 60V so I left it as is as this is 3.75v per cell which is still within the safe limits for LifePO4 but BMS should catch the voltage long before it gets to this level anyway)

Discharge UNV_Pro: 42.0V (Was also unsure exactly what this setting was but I interpreted as a minimum voltage the inverter would allow while discharging. It was set at default at 42V so I left it as is as this is 2.625V per cell which is still within the safe limits for LifePO4 but BMS should catch it first also)

I am open to correction on any of these, most of which I got from diysolarforum.com, but there does appear to be plenty of debate around the correct settings.

Playing with the settings I changed the Overcharge SOC to 95% last night and the inverter correctly only charged the cells to 95% last night. Haven’t really tested any of the other ones but for my purposes this seems to be working well. I also connected the two BMS together via the RS485 ports and could see absolutely no difference. No beep, no change of lights on the BMS, nothing visibly different at all in the JKBMS app. I have only used the app to configure so probably need to log into the BMS with a laptop to be able to see what this connection actually does.

irishchris · 17-11-2023 6:14pm

https://www.boards.ie/discussion/comment/121380433#Comment_121380433

Nice one that you got it sorted and working fine for your setup. I picked one up too and replacing my seplos v1 with it. Seplos was ok and will do as backup should ever have a bms fail in future. The jk was more of a hobby interest purchase as much as anything rather than necessity.

I see it is back down to €136 again for the 11/11 sale. Cracking value compared to what I paid last year for my seplos.

Screenshot_2023-11-17-17-03-43-401_com.alibaba.aliexpresshd.jpg

https://www.boards.ie/discussion/comment/121374317#Comment_121374317

I must watch it again but I thought he mentioned it did have this feature albeit a pack voltage not per cell?

patricklifep04 · 28-11-2023 10:32am

hello les amis voici ma contribution firmware 14.10 quels bug de communication en // et aussi perte du 2emes bms en// un peux dessus j'espere encore une mis a jours supérieur

JKBMS-V14.10(2).rar

jk-bms-monitor-2.1.0.15-setup.rar

a la version 14.10

insular1 · 29-11-2023 1:07pm

I had a weird issue yesterday where both of my JKBMS controlled batteries were sitting around 51V but one was reading 15% SOC and the other was reading 1% SOC. All cells were within a few millivolts of each other with the lowest cell on the 1% SOC was 3.158v so not caused by a runaway cell or anything. Normally both batteries sit at the same SOC. They were both charging and discharging as normal despite the SOC being 1%, it's just unfortunately that happened to be the battery I had communicating with the inverter so it had stopped discharging at that point and started force charging from the grid.

Any ideas what could cause this? Any way to calibrate the SOC% on JKBMS?

patricklifep04 · 29-11-2023 5:54pm

hello good evening I had the same thing you have to put pressure on who modifies the firmware 14.10 the latest which corrects all the problems

S' · 07-12-2023 8:26pm

Going to hook up a 200a JK BMS in the coming days.

Wondering do I need any other fuse protection with this setup?

Should I have a 250a mega fuse between positive of Batteries and disconnector?

I have two 35mm cables each side of the BMS and 70mm from disconnector to Inverter.

insular1 · 07-12-2023 8:41pm

This is the set up I have. Only running with 2 batteries at present but cells for a third are on the way. I used 150amp mega fuses as with multiple batteries I never see anywhere near that.

Battery to Inverter JKBMS.jpg

graememk · 07-12-2023 8:49pm

The projoy is somewhat redundant as each battery is switched.

No harm having it though. Although if you are pushing higher currents it wont handle it.

@S' you don't need another fuse or disconnect unless your adding more packs then each pack would need to be fused and have its own disconnect.

insular1 · 07-12-2023 9:11pm

Yeah was there from my initial battery before I went the DIY route so I just left it in. Will have to take it out if I upgrade to a sunsynk.

irishchris · 08-12-2023 11:32am

Didn't realise the jkbms only had the negative running through it and not both positive and negative like the seplos?

https://www.boards.ie/discussion/comment/121468156#Comment_121468156

https://www.boards.ie/discussion/comment/121468105#Comment_121468105

insular1 · 08-12-2023 1:06pm

Yeah just the negative. It has an extra cable running directly from the BMS to the battery positive for monitoring.

insular1 · 09-12-2023 10:29pm

https://youtu.be/qqSEPzbL_i8?si=DvD0-h_PZyL5PL2p

Some promising updates on the latest firmware. Will see how his testing pans out. Since doing a couple of full charge/discharge cycles mine are working fine for my use so haven't bothered with any firmware updates yet but these latest changes might convince me to update if his testing shows it's good. Will probably wait until he's tested the parallel BMS setup first just to be sure.

insular1 · 12-12-2023 10:13pm

https://www.youtube.com/watch?v=F6OnHQ0TEbg

Andy's latest video. New firmware seems to fix all issues. Still waiting for him to test the paralell functioning of it but looks like I'll be trying to do these updates this weekend!

unkel · 12-12-2023 11:13pm

Perfection 😎

"Why would you buy anything else?"

SD_DRACULA · 13-12-2023 1:22am

Any idea if the FW can be updated via the mobile app or windows software only.

The "manual" says prepare rj45 usb which can literally be anything, rs485 maybe? Also which port on the breakout board? There's like 3 rs485 ports

insular1 · 13-12-2023 9:36am

Yeah it's only via windows software from what I've read. Based on Andy's video I bought an RS485 to usb cable. Haven't tried it yet as was waiting for him to test the newest firmware before doing anything so not sure which port. Think in his original video it was the main inverter rs485 port, the one on the furthest left.

I'll hopefully get to try it this weekend and will let you know.

SD_DRACULA · 13-12-2023 11:09am

Cool let me know I will need to do the same myself.

He has the Fw files and some pdf links on his video.

SD_DRACULA · 16-12-2023 3:07pm

Got these files from JK themselves, latest FW v14.13, and some PDFs which contain handy info like pin-outs, how to flash FW, etc

JKBMS Inverter BMS instructions.pdf

JK-PD2A16S-15P V1.01说明书.pdf

V14.13-20231213T001308Z-001.zip

jasgrif11 · 18-12-2023 5:36pm

Can someone please help explain the optimum settings for Absorption voltage and JKBMS?

I set the Absorption voltage to 55.2V and the Absorption time to 30 minutes. My cells never reach 55.2V without the total voltage first hitting 100% (which means it stops charging). I'm going to try a full discharge/charge (at 2500w) with "Charging Manually (top bal)" turned on to see if they need a little top balancing.

When should I use the following?:

Charging float mode

Float Time

Bulk Offset

insular1 · 18-12-2023 8:16pm

Which version of the BMS do you have? I haven't got some of those settings on my JK-PB1A16S15P but I haven't updated to the latest firmware yet and I know that gives access to more settings.

jasgrif11 · 18-12-2023 9:24pm

Technically, it's an ESP32 board and CAN module that I'm using in conjunction with the JKBMS to control the inverter. Sorry I should've made that clear. Here is the repo https://github.com/Uksa007/esphome-jk-bms-can.

My JK version is JK B2A24S20P SMART BMS

insular1 · 19-12-2023 9:44am

Sorry, that's above my skill set at the moment! Looks very cool though.

S' · 22-12-2023 10:26am

Having a few wee issues setting up new jk BMS (PB2A16S20p) with a deye inverter. CAN comms seems to be not working. SOC way off. Any ideas. Is Lithium Mode 00 correct?

BTW the BMS is running latest firmware

JKBMS

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