Low cost BMS

[hbthink]

Does anyone here have a legible schematic, I cannot read the jpg from page 1.

Steve

[harlequin2]

Send me a pm with your email address and I'll send you all the files, but it won't be until after 20 August as I am away until then.

[harlequin2]

I'm back after an excellent holiday and moving right along with this little project. I have 100 pcbs for the cell modules with a couple assembled and thinking about building another 50 or so. The master control unit has been designed and most of the software written, just waiting on some pcbs from China to put one together.
There's a photo of an assembled cell module attached. Note that it is hand soldered - future ones I will do in the oven.

Also, updated schematics, firmware and pcb files are available to anyone interested.

[harlequin2]

First iteration of the master control unit is up and running.
Here's a picture showing Vh (high), Vl(low), T(emp)h and Tl for a couple of LiPO4 cells on the bench. Temp is deg C of course! Voltages are in millivolts.

[kovgab3]

Hi harlequin2,

I tried to send you a PM, but since I am a newbie, I can not do that...

I have seen your work regarding the cheap BMS, and I think it is amazing, congratulations.
I am looking for an application like this for a while...
I would be very grateful, if you could send me the files of the project (as you mentioned, the schematic, pcb plan, etc.)

However I would like to use an Arduino (~Atmel AVR) based master unit. Can you please explain in depth the communication method of these slave modules? (or can I figure it out from your source files?)

Do you plan perhaps to sell bare PCBs or even fully mounted modules? I think I would be a buyer for 20pcs at the beginning

Thank you again,
Best regards,
kovgab3

[harlequin2]

Yes, I will have some spare pcbs for both the cell modules and the control unit. Bare pcbs will cost you $2 for the cell modules and $10 for the control unit, plus postage - via UPS or somesuch, probably about $30.
I admire anyone who attempts to re-do it for the Arduino!

Here's a picture of the cell modules installed in one of my car's battery boxes:

[toledi]

Hi harlequin2,

I tried to send you a PM, but since I am a newbie, I can not do that...

I to think it is amazing and I to would be very grateful, if you could send me the files of the project (as you mentioned, the schematic, pcb plan, etc.)

Also I think I would need Bare pcbs for the cell modules (30x) and (1x) for the control unit (as soon as I see the schematics)

Than you, and keep up the good work

Gretings from SLOVENIA (EU)
toledi

[harlequin2]

Happy to send the files. I'll drop you a line with my email address.
Note the cell modules are designed to fit cells with terminal spacings from 60 to 64 mm (slotted holes) which covers both CALB and Thunder Sky 40 AH cells and I think Calb 70 and TS 60 cells. If you want to use them with larger cells you have to bolt one end of the module to a cell terminal and make a wire link to the other.

[harlequin2]

Just a brief update:
The whole 45 cell system is now up and running in my car. A few refinements to add to the control unit yet, but it is almost finished and working well.

[sawickm]

Originally Posted by harlequin2

Just a brief update:
The whole 45 cell system is now up and running in my car. A few refinements to add to the control unit yet, but it is almost finished and working well.

Let me know when you want to post your BMS project files to the ReVolt Wiki !!!

-Mark