DGJBD Bluetooth BMS - a short review

[Pierre]

Until recently I have been using Daly Common Port BMS's in my experimental 12v LiFE 100Ah 4S battery pack. Very pleasing results getting in excess of 1500Wh on the discharge cycles. 'Curiosity killed the Cat' and after reading / watching Will experimenting with Bluetooth BMS's I decided that I wanted to see what goes on inside the 'brain' . I promptly ordered a DGJBD 4s 100a unit from China for $68 plus shipping.
I was pleasantly surprised when it arrived - very nice piece of kit, well made and comes with a bluetooth dongle and RS232 / USB converter and cable to connect
to PC. Wired it all up and downloaded JBD Tools V1.6 and iOS app and started experimenting. The manual, which I had to download, is quite well written bar a few
translation issues. Bluetooth as well as the serial connection work extremely well and connections are established within a few seconds. All the settings are accessible via both communication media and I am still happily experimenting with tweaking / adjusting parameters and have built up a collection of 7 different configurations.
The unit has two built-in temp. sensors and the one is on a short fly lead for strategic placement and both can be calibrated. All the other protection actions like
pack and individual cell over / under voltages , over current , cell balancing etc work very well.
The only issue I have is the calibration of the current sensing circuitry - one is supposed to be able calibrate (1) idle current (2) charge current and (3) discharge current and the device will then calculate the resultant current flow and display the result in the app. I have contacted the supplier, who then refers it to the engineer, on numerous occasions but they keep on telling me to follow the manual or to detach / re-attach all the connections to the BMS. This seems silly as all the other functions work perfectly. I think that something is lost 'in translation' due to the language barrier. The current indications have no correlation with the actual current flows , not even ratio wise. Maybe someone on the forum has experience with this particular BMS and can help me solve my 'finger trouble'
My overall impression of the device / monitoring software is very possitive and the coup de grace will be to resolve the current indication.
Looking forward to your replies / recommendations.

 

[Steve_S]

A link to the product would be helpful.

 

[Pierre]

Here goes Steve : https://www.alibaba.com/product-det...13.html?spm=a2700.12243863.0.0.2dee3e5fmAkZRT

 

[Steve_S]

Here goes Steve : https://www.alibaba.com/product-det...13.html?spm=a2700.12243863.0.0.2dee3e5fmAkZRT

They have some interesting goodies and well priced too. Cool.

 

[Pierre]

Their service is great and they always reply to emails etc.
The product code is : JBD-SP04S020

 

[Pierre]

More information here : https://hackaday.io/project/162806-jbd-bms-protocol

 

[Pierre]

Sorted !! I can now report that the current display is working 100%. All it was is the proper calibration setting in the software of the current measuring shunt resistor value. This is not mentioned anywhere in the 17 page manual and thanks to a post on Hackaday.IO re the calibration of the over current protection which got me thinking. That something this insignificant can mess you around for days.

 

[thedodgersonline]

Just bough one as well - will see how it goes. Thanks for the review. Bought the 120A version.
Stay well in these trying times

 

[thedodgersonline]

well made and comes with a bluetooth dongle and RS232 / USB converter and cable to connect
to PC. Wired it all up and downloaded JBD Tools V1.6 and iOS app and started experimenting.

Hi Pierre
2 questions
1. Can you complete the setup via the app and blue tooth or do you need the RS232 / USB converter?
2. Where did you download the manual from
Thanks and Regards

 

[Pierre]

Hi Pierre
2 questions
1. Can you complete the setup via the app and blue tooth or do you need the RS232 / USB converter?
2. Where did you download the manual from
Thanks and Regards

Hi D , (1) there are a few parameters that you can only set using the RS232 link to your PC and the presentation is slightly different. I use the app mostly for monitoring once the pack is in the portable battery box or out of normal reach where it is difficult to plug the cable in. I suggest that you use the app first as all the important functions can be set on it.
(2) I asked the supplier for a copy the manual and they emailed me a pdf. If you have problems sourcing it , let me know and I will post it here - maybe you get a slightly updated version.
Where are you located ? We have a 21 day lock down as from Fri morning.
Keep safe and regards.

 

[Pierre]

By request herewith a copy of the programming manual for the JBD Tools app used for the BMS under discussion.

 

[Pierre]

Further to the above a copy of the JBD Tools manual I downloaded from the Hackaday.io site. a Few more parameters settings are covered here.

 

[Pierre]

I have been playing with this BMS for a while now and must must say that I am very satisfied with the performance. All the protection functions work great - the only one that I have not tested is the 'low temp cut off'. This unit has two NTC sensors - the one is on a fly lead but the other one is embedded somewhere in the build. I have dunked the one (on the fly lead) into a glass of melting ice but it did not shut off. My contention is that both sensor inputs are required to trigger a 'shut off' and that implies that I will have to 'freeze' the complete unit as Will P does.
In my present battery pack I have one cell that peaks and one that dips before the others and as I am waiting for cells to arrive from China I cannot swap them out. This is where the programmable functions come in. I was able to build up a profile to switch these two cells off at certain voltages and although the pack performance has been slightly compromised it still yields at least 80% of its total capacity.
The cell balance function is also fully programmable and can balance to my preset value of delta 10mV. The balancer only discharges those cells that are over a preset voltage and delta. It does not 'take' from high cells and 'give' to lower cells and I think this is what is referred to as 'passive' balancing. The balance function can be preset to be active during the charge cycle as well if required.
The peak discharge current tested so far was around 85 amps for about 15 minutes and the unit hardly breaks a sweat. To test the capacity of the pack I discharge typically at about 63 amps into a Victron Smart Phoenix 12/1200 inverter supplying a panel with 5x lamp holders which I built as a test load. With this method I can add and remove lamps to vary the load as required and I use 230v 150w BC halogen lamps. I do not like the noise of my wife's hairdryer or my heatgun running all the time and it is cheaper to replace a lamp .
This test continues until the protection ( Cell UV or Pack UV ) triggers a disconnect. To charge back up again I use a Victron Smart Charger 12v/20amp/10amp with a LFP charge profile.
Communication with the apps , both bluetooth and RS232/485 , is established within seconds and configs can be stored and retrieved in a jiffy to upload / download to the eeprom.
Testing is ongoing and I will report on future performance.
For $68 this is a one of the best BMS buys out there ! As Will always says " I am not sponsored and bought it with my own money"

 

[Pierre]

Go here to watch Will's video on this BMS :

 

[Pierre]

Here I have attached some screenshots of the three screens displayed in the iOS app on my iPad. All these settings are editable using the app.

 

[Pierre]

It is still better to get the Windows app to run on your computer via RS232/UART as you get access to a few more settings and the best of all , while testing the capacity of your battery pack , you do not have to wait up for 5hrs or so to monitor / record the performance . The Windows app has a feature called 'Save data' . Once activated the app saves the state of the pack to an Excel file every 1 second. Which other BMS has this function ?

 

[Pierre]

I was staring at columns and lines of data recorded by the app during on of my test discharge cycles and though it to be a good idea to represent some data in the form of line graphs -- so I generated the attached in Excel (2010). Plug in your own values and generate same for your own packs.
Please give me a 'like' if it works.

Sorry ! System does not allow me to upload .xlsx files. Why not Will P ?

 

[Pierre]

Refer to post above (#17) . I have attached the pdf's so long.

 

[Pierre]

Deleted.

 

[Pierre]

Deleted.