Buy FOCBOX Unity

DIY 6S to 12S BMS with CAN - DieBieMS


I just read the thread about the upgrade, just awesome progress!

But now, the VESC is kind of the CAN master when using and need to be powered on before the communication gets active. I prefer not having my VESCs energized for an hour or longer during charge.

Does the D.B.MS forward CAN data? if so I would be able to connect the to the BMS serial port instead of to the VESC.
This would open up some possibilities:

  • The VESC would not have to be powered-on to monitor the charge process or battery state.
  • would be able to send push messages when charge is done or if there is an issue
  • With push-2-start I would be able to check my battery state before rolling off
  • At some point the BMS could also store VESC logging to the SDcard.


So I might have missed it but what is the current amp capacity for discharge of the unit?


So I am waiting for my DieBie to arrive. What is the recommended charger for a 12s setup? What are you guys using.

If I have read correct info. It is recommended that charger is about 3V higher than the full charged voltage of battery.


Ive read that these could be good for the DieBieMS. Could be useful fo you :slight_smile:

DieBieMS v0.8 Batch 3

So what is the status of the phone app? Is there one for IOS?

#542 works like a charm, not for configuration though


damnz, those meanwell’s are expensive :anguished:

for my 10S setup I use an aliexpress power supply, 42v 3A, I paid something in the range of 25€
just search for “10s lithium charger”


Right, I’ve just bookmarked those because @JTAG had mentioned them somewhere.
Additionally, I believe you need an extra 3v on top of your nominal voltage for your charger, so having the adjustable Voltage and Amperage so those are nice for that flexibility


What do you mean? You are not able to configure VESC via metr app?

#546 is designed for VESC and works great for logging and configuration!

They are currently integrating DieBieMS features (state of charge with fancy animation), no configuration page for DBMS (jet?)
you can still do so via the terminal and CAN fwd (ID:10) in the app.


@JTAG would you reccomend cell level fusing in use with this?


@JTAG didn’t see it anywhere, but would this work with Hobbywing Max6 ESCs and off the shelf Turnigy cell packs? Do I need to have a Vedder based ESC?


Any update on this project?! Looks like it would be amazing for some of us :slight_smile:


What about simple PWM?

I am not really familiar with switching losses, heating and stuff. But in my understanding a buck converter is only a PWM switch with additional smoothing by caps and coil. And for buck converters efficiency rises for low voltage differences (vin vs vout). So if I am right, the losses at high dutycycle switching should be small and from ~55V to 36V you are always above 65% duty, for Lipos even above 80% duty.
And even if there is some heating, you could always regulate the charge current down according to the temperature of the closest NTC. So you do not have to have a CC/CV powersupply but a CV is sufficient (like the cheap ledstrip powersupplys)

So what do you think, could a simple software 40kHz PWM regulate the input current?


Hey Guys,

I need you help. @JTAG

Just attached the DieBieMS to my 2 x 12s5p == 12s10p.
The balance cables and PACK +/- are connected.

  • DieBieMS does power up. HW V0.7
  • DieBieMS-Tools can connect to the MS states FW 0.16
  • FW Upload does work.
  • But after reboot - it is still 0.16
  • Can NOT read / NOT write values with the DieBieMS-Tool
  • only Terminal commands.
  • Strange “State of charge” - 1.5% - at 12s with 48.97V it should be above 90%

What am I doing wrong?

Please find all data below.

------- BMS Info -------
Firmware: V0.16
Hardware: V0.3
Name : DieBieMS
UUID: 33 00 3E 00 10 57 34 56 36 30 33 20
------- End BMS Info -------

----- Cell voltages -----
Cell voltage 0 : 4.088V
Cell voltage 1 : 4.089V
Cell voltage 2 : 4.080V
Cell voltage 3 : 4.089V
Cell voltage 4 : 4.089V
Cell voltage 5 : 4.089V
Cell voltage 6 : 4.089V
Cell voltage 7 : 4.088V
Cell voltage 8 : 4.089V
Cell voltage 9 : 4.089V
Cell voltage10 : 4.089V
Cell voltage11 : 4.083V
Cell voltage high : 4.089V
Cell voltage low : 4.080V
Cell voltage average : 4.088V
Cell voltage mismatch : 0.009V
----- End Cell voltages -----

-----Battery Pack Status-----
Pack voltage : 48.97V
Pack current : 0.02A
State of charge : 1.4%
Remaining capacity : 0.57Ah
Operational state : External (USB or CAN)
Load voltage : 0.00V
Cell voltage high : 4.089V
Cell voltage low : 4.082V
Cell voltage average : 4.088V
Cell voltage mismatch : 0.008V
Discharge enabled : False
Charge enabled : False
—End Battery Pack Status—

— BMS Configuration —
NoOfCells : 12
batteryCapacity : 41.00Ah
cellHardUnderVoltage : 3.400V
cellHardOverVoltage : 4.250V
cellSoftUnderVoltage : 3.300V
cellSoftOverVoltage : 4.250V
cellBalanceStart : 4.100V
cellBalanceDiffThreshold : 0.010V
CAN ID : 10
— End BMS Configuration —


OK @JTAG - read the whole thread again and found the part where you describe the bootloader_jump command.

Now it says v0.21 in the DieBieMS-Tool - but the LCD states v0.17 at boot.

Is this normal?


Hi guys!

Sorry for the lack of response from me lately I have been very busy. But also busy on adding new features to the BMS and the interface. The most important thing I am working on is a self test feature to test the BMS after production and changing the hardware to add test pads for a test fixture.

I will soon take time to answer all unanswered questions soon!

And for the last question, I am sorry that might indeed be a bug :stuck_out_tongue: . I still have to automate incrementing the firmware version on every place in the firmware automatically.


DieBieMS is now managing 12s10p of 20700B.

Wow - this is just the coolest BMS around!
Thanks @JTAG from Hamburg.


@JTAG anything buddy?


you can maybe still get one here