JK BMS Current Consumption (JK-B2A8S20P-H)

[RV10flyer]

My pushbutton turns the JK on and off. You need to hold the button in for 5-seconds or so.

You are correct. Thank you.

 

[patrickm]

Everyone of my JK's consume from 10 to 14 mA. The LCD consumes 32 mA. they are no different than my other seven brands of PMS is that I have used. It's really not that much power. Less than 1W.

Ok that's certainly less than 65mA that was mentioned earlier but that is still around 8Ah per month. I'll order a couple to test. @RV10flyer Do you use the RS485 port?

 

[ocular]

Is it possible that JK 4-8S consumes more than the other > 25V JKBMSs because of the 4S-8S needing a DC-DC converter? Reading some of the threads here it seems the newer 4s-8s has collected some of its own problems that the manufacturer/seller has been silent about- not good form

 

[hwse]

You are correct. Thank you.

That button and the ability to turn it on and off at will is rather handy. Except for that time when I turned off and never turned back on.

 

[MatMit]

I have 10 various bms's. All between 0.003-0.040A at 53.3V. My JK 150A with 2A balance consumes between 0.005-0.010A. My JBD with the contactor consumes 0.040A. Overkill= 0.017A. Ant= 0.003A. QUCC= 0.019A. Daly= 0.015A.

Edit: My 6 new JK200A 8S-20S (Wired as 16S) BMS's consume 14mA and the LCD consumes 29mA. All you need is a toggle switch on the red wire from gps connector to turn off LCD.

Yes i had the same Problem with shutting off the screen. I just disconnected the GPS plug, but toggle switch will be the way to go! would be nice if they already deliver it with a switch. or if they update the firmware do double tab the screen to turn it on and off. should be no problem?

 

[SolaroSsaurius]

You really don't need a big heater if you put your cells in an proper insulated box. I use 7W polyimide heater on mine (not with the heater output on the BMS because mine don't have it but with a simple electronic thermostat) which keeps the batteries warm even in the worst conditions.

Hi!
How much is your box insulated, what kind of ambient temperature are they subject to and what type of cells are they?

Is overheating an issue with your setup?

I'm about to build a 24v battery based on 280Ah Eve cells for an RV, and I'm thinking about putting them in a metal box to prevent some calamity may the worst happen, but I am a little bit worried with heat dissipation.
They will see a max discharge of around 120A, occasionally (30 -45 mins , twice a day)

Thanks for your input!

 

[upnorthandpersonal]

I have subjected my battery to below -20C (280Ah EVE LiFePO4 cells), and this happens a few times a year. The box is insulated with about 10cm of fiberglass, but I plan on testing a PIR insulated box. The heating is controlled with a thermostat, so no overheating. Also, it's a 7W heating element...

 

[satmaster2000]

Hi Guys! Long time gone! At some point I found a package from China in my mailbox, containing some tiny-tiny six-pin chips. First I had no clue what they are for, nor could I remember to have them ordered in China. Turns out, these were the Chips for my JK-BMS with the high standby power consumption ?‍?

So I swapped them out. But what a nightmare! I am not soldering SMD-parts for the first time, but surely not for a living, but bloody hell, one of the nearby resistors got unintendingly unsoldered in the process and after searching it for a looong time I found it in the sponge where I clean my solderiron-tip! ?

Anyway, with each chip swapped the current went down and ended at round about 65mA @ 13.2V. So almost as low as my second, but identical JK-BMS.

Not fantastically low, but at least nothing get's hot anymore, or the BMS doesn't start at all, which sometimes happened. Still, I think the idle consumption is a bit on the high side for these 4-8s BMS's. As somebody else wrote, that problem might only effect the 4-8s BMS's as they seem to need dedicated DC-DC converters.

These are the Chips I swapped out: (note the picture was taken BEFORE my butchery , but doesn't look to bad either and after all it's still functional!)


Cheers sergio

 

[patrickm]

Do you have any other photos of the PCB?

 

[satmaster2000]

There you go:

 

[patrickm]

Thank you!

 

[ocular]

Thanks Satmaster2000 for followup. So to summarise there seemed to be an intial version of the JKBMS 4s-8s (?about x20 - according to @Nami) that had DC DC converters that ran hot and the BMS consumed 1600mW causing instability. ( not sure if these were the ones that caused a lot of noise with power supplies and shunts?)
The subsequent version seemed to come with a heater pad connection (buyers seemed to get heater version even tho not ordered)
The version with the newer DC DC converters consume about 800mW. The original 8-20S JKBMS consume about 560mW. (legacy of needing DC DC converter?)

Can someone please confirm the power consumption of the current JK BMS 4s-8s when manually turned off with the button?

 

[SvenT]

Is it sufficient to measure the current in the B+ wire to the BMS?

800mW would mean, that a fully charged 280Ah battery is empty after 175 days even if the BMS is off?

 

[matteo.g]

Is it sufficient to measure the current in the B+ wire to the BMS?

This depends if the BMS draws power from the most positive cell (B+) or if it uses power from cell 2 or 3 as some BMS do.
To be 100% sure you are measuring correctly, you should measure at B- (both on power wire and balance wire) with no load or charger attached.

 

[cdvreede]

just installed a B2A8S20P and was wondering about the self consumption. Do I understand from the tread that its about 65mA when active (without balancer active) and a really low number (how low??) once the BMS is put to sleep using the pushbutton 5-second thing??

Thnx

 

[drlucid]

Which JK BMS's are affected by the high idle current consumption? I purchased mine last Summer June 2022, should I be concerned and check it out further? It is kind of a pain for me to disassemble the enclosure it is in so I thought I'd ask before I go through this extra effort. Thanks,

Russell

 

[TimE]

I see that your BMS is an earlier version. After January 2022, we agreed to replace all BMS interfaces with those in the picture,
I will contact the engineer to arrange a link cable of the previous interface for you,

View attachment 97979

I have the later BMS and the small 2.5" display. Does the larger display have any audible alarms? It would be great to have an audible alarm to tell me if the BMS is about to shut down the battery. On a boat this is very important as the battery runs navigation lights, chart plotter, radar, etc

 

[jandb]

With the Softwareversion (V11.17H) seems to be some new information available on the main page. I think I understand "Heat Current" and "Heating Status" but what does "Charg. Plugged" mean?
View attachment 103342
first I thougt it will detect if I am Charging the Battery (Daly and Jiabada do) but as you can see from the screenshot, I am charging at the moment with around 200W but "Charg. Plugged" still says: "Not Plugged"
@Nami perhaps you can tell?

I had the same question regarding “charg. plugged”… I contacted the manufacturer/seller on AliExpress and they informed me it is the indicating whether a heating pad is connected or not. So the indication is rather misleading.
I made the suggestion to change this description in following update of the app… ?

 

[OffgridSystems]

It seems like there is a real need for an open source scalable BMS for the DIY community. Sourcing reasonably priced copper inlay PCBs for the MOSFET power path would be an issue that would need to be resolved for that to happen.

I've got decades of power electronics experience, including power inverters, battery chargers, and BMS's. Let me know if you or anyone want to collaborate on an open source BMS. I've reviewed what is currently available on-line and github, and JK is years ahead. But it's not perfect and it's not open.
Tim

 

[rilonau]

I've got decades of power electronics experience, including power inverters, battery chargers, and BMS's. Let me know if you or anyone want to collaborate on an open source BMS. I've reviewed what is currently available on-line and github, and JK is years ahead. But it's not perfect and it's not open.
Tim

Sounds really good and i would be interested. I could probably not contribute really much, but maybe some ideas. I have some basic knowledge in electronics including simple circuits with transistors, mosfets and build some easy power supplies. I even modded some heavy server power supplies to have adjustable voltage output to some extend. My biggest is a beefy 6 kW server psu that delivers 36...52V DC at more than 100 Amps. Couldn't get it to run from lower voltage as the UVP is very resistive.