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  1. S

    Hacking "JBLTools" Chinese Bluetooth BMS boards

    The comms protocol for these boards is explained in this thread Simon
  2. S

    Generic-Chinese-Bluetooth-BMS-communication-protocol

    Its been a while since I posted to this thread, amazing how time flies. Thanks @Aadamz5 for the spreadsheet, I will be looking at the calibration next, there is some interesting info on the calibration registers in that spreadsheet. I have written a little Python program to read and write the...
  3. S

    Generic-Chinese-Bluetooth-BMS-communication-protocol

    I don't know of any way you can get the Atmel processor that runs the BMS boards to send 'raw' commands to the TI chip. You could remove or disable the Atmel chip and talk directly to the TI chips via I2C bus if you wanted to. Simon
  4. S

    Generic-Chinese-Bluetooth-BMS-communication-protocol

    There are three variants of the BQ76940, the 76920 has five cell inputs, the 76930 has 10 inputs and the 76940 has 15 inputs. Any of the BMSs that handle more than 15 cells do indeed have more than one TI chip. The 'high voltage' chip has its I2C bus coms opto isolated so the Atmel processor...
  5. S

    Generic-Chinese-Bluetooth-BMS-communication-protocol

    This is where I got my latest batch of BMSs, https://www.aliexpress.com/item/15S-Smart-Li-ion-Battery-PCB-board-Bluetooth-Mobile-BMS-for-63V-Li-Ion-Ebike/32812066109.html I am fairly sure that any of the units using the xiaoxiang android ap or the Windows JBDTools program will be using the TI...
  6. S

    Generic-Chinese-Bluetooth-BMS-communication-protocol

    This link gives information on the 03,04,05 commands that give the information you want I have had limited success with switching the charge and discharge FETs on and off with the following. send DD A5 03 00 FF FD 77 DD A5 04 00 FF FC 77 DD 5A 00 02 56 78 FF 30 77 which is the same as getting...
  7. S

    Generic-Chinese-Bluetooth-BMS-communication-protocol

    I have done some further reverse engineering of the coms protocol for these BMS. I have decoded the majority of the Config settings that are displayed in the config tab. To read the config settings you first have to read the battery data information with these commands DD A5 03 00 FF FD 77 DD...
  8. S

    Hacking "JBLTools" Chinese Bluetooth BMS boards

    I have been using them on our E-Bikes for some time and they seem to work well. Only issue I have had is that connecting/disconnecting the bluetooth module can "glitch" the Atmel processor and hang the software. Only way to fix this is to toggle the reset pin on the processor or remove the...
  9. S

    Hacking "JBLTools" Chinese Bluetooth BMS boards

    If you click on the "spanner" button next to the "Post Reply" button you can subscribe. Interestingly I haven't been getting notifications via email recently, is there a problem? I agree. If you want to electrically isolate it you can use an opto isolated serial link and/or hook it up to...
  10. S

    Hacking "JBLTools" Chinese Bluetooth BMS boards

    I have been running Winston cells for over five years now. You are right, the cells in the photograph are a new batch of CALBs that I am using to put together a system for a friend. The black and red dots are the protective terminal covers that came with the new cells. I might reuse them when I...
  11. S

    Hacking "JBLTools" Chinese Bluetooth BMS boards

    These are screenshots from the software provided with the BMS And from my software reading the data from the BMS
  12. S

    Hacking "JBLTools" Chinese Bluetooth BMS boards

    No, the original shunts are 4mOhms and there are ten of them. https://www.aliexpress.com/store/product/48V-Smart-bluetooth-BMS-system-with-30A-discharge-current-for-54-6V-Battery-system-E-Bike/1379203_32733414980.html I started a tread a while ago detailing the communications protocol here...
  13. S

    Hacking "JBLTools" Chinese Bluetooth BMS boards

    There are a number Chinese Bluetooth PCBs that use the TI BQ76940 BMS controller/controllers connected to an Atmel 8 bit microcontroller looking like this. One of the main issues with these boards is the layout of the FETs that disconnect the battery from the rest of the world in the case of a...
  14. S

    Generic-Chinese-Bluetooth-BMS-communication-protocol

    There are a number of generic Bluetooth BMS units based around the TI BQ76940 BMS controller with a number of different configurations. I am not sure if they are manufactured by one or a number of different manufacturers. The thing they have in common is that they can be used with an Android app...
  15. S

    help for BMS with comunication

    Thanks for posting the pictures on how to configure the boards for different cell counts. My first impressions like yours are that this BMS is very good for the money. Software is a little rough around the edges but gives all the information that one needs, nice that you can calibrate the unit...
  16. S

    Is floating LFP batteries bad for them?

    Thanks David for all the information. The 3.34 volts float voltage I mentioned in my first post was arrived at experimentally by Gorden who posts on the Energy Matters forum as being the voltage at which to float an LFP battery after it has been charged to 3.45 volts with I think an absorb time...
  17. S

    Is floating LFP batteries bad for them?

    In my application in an off-grid power system charged by solar the battery can be fully charged before midday. Keeping it on float and fully charge for the rest of the day with intermittent loads is useful as I don't know how cloudy it is going to be over the next few days. I tend to agree...
  18. S

    Is floating LFP batteries bad for them?

    How full do they have to be before they sink? :D
  19. S

    Is floating LFP batteries bad for them?

    If you charge an LFP battery to nearly 100% full using solar power with a charge voltage of 3.45 V/cell at an end current of less than C/50 and then float the battery at 3.34 V/cell are you substantially decreasing the lifespan of the battery rather than just terminating the charge? I have seen...
  20. S

    Bottom balancing?

    Looks like Sunking is trying to restart this discussion after it had been done to death here, http://www.solarpaneltalk.com/showthread.php?19657-LiFeP04-Batteries-for-Solar-amp-BMS, I post under the name "karrak" in this forum. He is using exactly the same tactics here as on that forum, name...
  21. S

    Bafang BBSxx - fault finding and fixes

    Thanks aniken for you videos and commentary, I have found them very interesting. You mention that your drive powers down by itself on occasions. I wonder if this isn't being caused by the "sleep" function causing the unit to shut down after inactivity. The drive might detect activity as being...
  22. S

    Bafang BBSxx - fault finding and fixes

    This is a case of no news is good news, we only hear about the problems on this thread, don't hear from the hundreds if not thousands of people who are not having problems. This is a new product and is bound to have teething problems. I think the basic consensus it that these drives are well...
  23. S

    New Bafang Crank-Drives

    Total cost was US$515 delivered to Australia. I didn't bother with the programming as I can do the programming thanks to this thread.
  24. S

    New Bafang Crank-Drives

    Received a second 750W BBS02 about a week ago. First one ordered from Amy at GEB took six weeks and did not have the programming changes I asked for. Second one from http://www.conhismotor.com/ProductsList.asp?id=118 took seven days. Before I ordered the second one I asked Conhismotor whether...
  25. S

    Programming the Bafang Middrive BBS01+BBS02

    The connectors look like they maybe compatible with one of these http://www.altronics.com.au/index.asp?search=6+pin+waterproof&area=srch&Submit=SEARCH Hopefully my drive will arrive tomorrow after a six week wait. When it arrives I will drop into Altronics and see if i can get a match. The six...
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