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DGJBD Bluetooth BMS - a short review

kringineering said:
I had what I thought was a problem when testing the low temp cutoff. It seems to be a odd "feature" of the controller that was throwing me off. I expected in the battery status display to see the charging switch go to OFF when temperature is out of range and I was verifying it with a small current from a LED. Turns out you need (in my 120a version) at least 1 amp of charging before it will shut off. If your not actually charging it will not shut off. I found it only was effected by the thermistor on the wire. But I see in some version of the software there is a on/off (yes/no) for each thermistor. Attached is a photo of the location of the on board #2 thermistor, At the end of the row of FETs. So It appears to work. I wounder why everybody that sells these are so reluctant to provide any documentation.
Click to expand...
Thank you for your post. Wondered where the #2 NTC was. I agree about the documentation -- it is like an easter egg hunt !
 
More tidbits of information on the JBD SP04S020 BMS.

I found at least on my version (120 amp) the single temperature displayed on the bluetooth app Home page switches between the highest of the two Thermistors .

The setup values seem to be Volatile. If you unplug the balance leads the limits you changed from default will have to be reset.

The constant drain from the BMS seem to be about 23 ma and doesn't decrease when you turn the BMS off. So by itself it will discharge a 100AH battery in 181 days.

I measured the drop across the FETs at 23 amps load was 5 mv so that .115 watts. Extrapolated to full 120a current that would be .6 watts not bad. BUT the Shunt resistor is .0004 ohms (5 X .002 in parallel) that would be 5.76 watts at 120 A. So that seem like were most of the heat is generated.

I was told by the seller to get the android blue tooth app from www.jiabaida.com/xiaoxiang.apk Seems much less buggy that other I have tried.
 
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kringineering said:
More tidbits of information on the JBD SP04S020 BMS.

I found at least on my version (120 amp) the single temperature displayed on the bluetooth app Home page switches between the highest of the two Thermistors .

The setup values seem to be Volatile. If you unplug the balance leads the limits you changed from default will have to be reset.

The constant drain from the BMS seem to be about 23 ma and doesn't decrease when you turn the BMS off. So by itself it will discharge a 100AH battery in 181 days.

I measured the drop across the FETs at 23 amps load was 5 mv so that .115 watts. Extrapolated to full 120a current that would be .6 watts not bad. BUT the Shunt resistor is .0004 ohms (5 X .002 in parallel) that would be 5.76 watts at 120 A. So that seem like were most of the heat is generated.

I was told by the seller to get the android blue tooth app from www.jiabaida.com/xiaoxiang.apk Seems much less buggy that other I have tried.
Click to expand...
Thanks for posting your findings. Much appreciated. More post like this one by other users / experimenters are encouraged and welcomed as this BMS is becoming quite popular.
It seems that the iOS app is less quirky in certain areas of operation.
 
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I also have the JBD-SP04S020 but it won't connect to bluetooth via IOS. Somebody has the same problem and fixed it?
 
pierre said:
Their service is great and they always reply to emails etc.
The product code is : JBD-SP04S020
Click to expand...

I have the same unit 80Ah 4S BMS with this product code but I can't get my bluetooth connection working. Any tips?
 
Giela said:
I have the same unit 80Ah 4S BMS with this product code but I can't get my bluetooth connection working. Any tips?
Click to expand...
I really do not know. Mine worked 1st time and connects each time w/o fail. You obviously download the latest iOS app from the app store. To get full access to the settings on the BMS you need to pay a few $ when downloading. Once you plug the BT module into the BMS port and connect via the app the BT module will light up with a blue light. This is an indication that comms have been established.
Not sure if you have the UART RS232 module and cable to connect to your Windows PC. Read my earlier posts where to download the app and drivers etc. This way I also had no problems but you need to play around to get the feel of ‘keys’ and what they do. I have previously also posted the operations manual to guide you. Good luck.
 
pierre said:
I really do not know. Mine worked 1st time and connects each time w/o fail. You obviously download the latest iOS app from the app store. To get full access to the settings on the BMS you need to pay a few $ when downloading. Once you plug the BT module into the BMS port and connect via the app the BT module will light up with a blue light. This is an indication that comms have been established.
Not sure if you have the UART RS232 module and cable to connect to your Windows PC. Read my earlier posts where to download the app and drivers etc. This way I also had no problems but you need to play around to get the feel of ‘keys’ and what they do. I have previously also posted the operations manual to guide you. Good luck.
Click to expand...

I do not have the RS232 port/module. The weird thing is, it worked for a couple of minutes on the 4S 12V batterypack. I upgraded this pack to a 8S 12V pack in the meantime. The blue light is on but it keeps saying " waiting on data"

If it worked before and the parameters aren't changed I guess the device is broken somehow?!
 
Giela said:
I do not have the RS232 port/module. The weird thing is, it worked for a couple of minutes on the 4S 12V batterypack. I upgraded this pack to a 8S 12V pack in the meantime. The blue light is on but it keeps saying " waiting on data"

If it worked before and the parameters aren't changed I guess the device is broken somehow?!
Click to expand...
Do not understand. 8s is a 24v pack . So , do you have an 8s BMS ? How did you connect the 8 cells ?
 
No from the 8S I made 4 packs of 2S and then made a 12V pack. Like this configuration:
 
Giela said:
I do not have the RS232 port/module. The weird thing is, it worked for a couple of minutes on the 4S 12V batterypack. I upgraded this pack to a 8S 12V pack in the meantime. The blue light is on but it keeps saying " waiting on data"

If it worked before and the parameters aren't changed I guess the device is broken somehow?!
Click to expand...
Hi
I had a few of these BMS on test and I found that one stopped working. Blue light was on but no connection. The app did not even recognise it. I unplugged the Bluetooth module and plugged in a spare one and all was ok. I plugged the failed one into another BMS and it worked fine. Had some discussions with the vendor and they said that these modules can ‘lock’ themselves onto other receivers so the app will not see it.
BTW - you can buy the Bluetooth modules on AliExpress - they are about $A10 and there is free delivery. Might be worth investing in one (or two) if you plan on using them a lot.
Regards
 
Hi Pierre
Thanks for your review.
Been down your way in 1995 when south Africa won the world cup. Was in Joberg for the celebrations.
Spent 3mth travelling all round south Africa and Zimbabwe.
Walked up table mountain twice.
Cape town was my favorite spot. Less violence. friendly people those colored Africans, shared a beer with one in the back of a bus.

Back to the BMS (combined charge/discharge terminal)
When the BMS is in LV disconnect, will it still allow charge current through to charge. I assume when there is a higher voltage on the charge side of the mosfet than the battery side then the mosfet will turn on to allow charge current to flow. I think they would by n type mosfet as they seem to be switching the battery negative.
And in HV or HI current disconnect when will or in what condition will the load be reconnected to the battery.
Some BMS 's split the charge/discharge leads to allow for this.

Hi Thedodgeronlin
Your the closest poster to where i live that i have found on this forum
I live in Agnes water and most of my family live around Noosa heads.
 
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Hi @grey nomad , thanks for your post and very pleased that you enjoyed your visit to ZA. The Cape will not be the same without our beloved brown people ! They are indeed one of a kind with their quick wit and friendliness. They speak a mixture of Afrikaans / English / Malay and many colloquialisms.
You can set the OV and recovery points on the BMS. As soon as the load current exceeds the charge current ( if any ) and the recovery point is reached the load will be re-connected. I have sat here watching the BMS toggle between load / no load and charge / no charge conditions without having to reset anything. The FETs just merily switch between on and off .
@thedodgersonline is also an avid user of this BMS and we have had a few interactions as you can see from my review. I know he is not to happy with the BT (Blue tooth) coverage - I wonder if he ever soldered that little antenna on as I suggested ;) .
 
Hows it Pierre
My parents are Dutch and have a uncle that lived in Durban. I don't think he had trouble picking up the Africans language.
Like you i like the idea of using a laptop to communicate with BMS
I found a youtube video
that you may have not seen that mentions a guy that has played with the program and has a manual and latest software. It maybe of some use. https://hackaday.io/project/162806-jbd-bms-protocol.
I haven't made up my mind as to weather to go with 2 ea 12v 150ah bateries , one for redundency or 1 only 280ah from XUBA alibarba supplier that a lot of people on here has purchase and said they where a good deal.
In your experience have you found if a battery was going to fail, do you get any prior warning.(eg bad cell)
I would like to have some backup for my essential power to fridges.
 
grey nomad said:
Hows it Pierre
My parents are Dutch and have a uncle that lived in Durban. I don't think he had trouble picking up the Africans language.
Like you i like the idea of using a laptop to communicate with BMS
I found a youtube video
that you may have not seen that mentions a guy that has played with the program and has a manual and latest software. It maybe of some use. https://hackaday.io/project/162806-jbd-bms-protocol.
I haven't made up my mind as to weather to go with 2 ea 12v 150ah bateries , one for redundency or 1 only 280ah from XUBA alibarba supplier that a lot of people on here has purchase and said they where a good deal.
In your experience have you found if a battery was going to fail, do you get any prior warning.(eg bad cell)
I would like to have some backup for my essential power to fridges.
Click to expand...
Hi Nomad , I have been using the Hackaday files as mentioned in my review.
I use both the BT and RS485/232 apps with great success. The Xuba batteries seem to be very popular and I would go for the 1 x 280Ah Xuba because 2 x parallel batteries call for 2 x BMS's if you want to monitor each cell individually and track their performance. You can predict from the cell voltage if a particular cell is out of 'balance' with the rest in the pack. As long as all the cells track say within 50 - 80mV of each other ( I am achieving 3 - 20mV cells delta with A grade cells ) on the flat portion of the discharge curve you will be o.k. . Sometimes cells tend to drift further apart once the pack reaches the 'knees' on the charge / discharge curve.
Monitoring the performance of the individual cells will help you to predict an early cell failure. Cells do not just fail in an instant under normal use and rather gradually degrade.
 
pierre said:
Have you soldered that wire antenna onto the BT yet for extra range ?
Click to expand...
Hi Pierre
Not yet no as I am busy on rebuilding my camper. Built 3 more slim batteries as well and busy cycling and load testing them so my battery is on the back burner at the minute.

Regards
 
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