I'm working an a generic BMS which can be used for Vectrix with Leaf cells, or any other chemistry.
The BMS will do as it name implies, just monitoring so no active balancing for now.
The last weeks have been really busy but i could find some spare time to:
- think the whole thing over
- create schematics with Eagle
- setup prototyping
- working on the software (Atmel based)
- create PCB's in SMD format
- get familiar with the SMD reflow proces and all
- creating first batch of boards
The system is modular based of 8-channel boards which can measure 8 individual cells connected in series.
It can measure between 1 - 15V per cell so it can be used for any chemistry or setup.
The current backplane/mainboard can take upto 5 boards so its a 40cell max for now.
It is designed for 64cells max though with a max voltage of 200V for the pack (but more cells with max 500V is possible also when other parts are used).
Heres a picture of the bare modular boards, pretty small, just under 5x5cm each.
And this is after my first attempt of SMD reflowing :-)
I'm currently working on the displaying part.
At this time i'm thinking of an (optional) 20x4 LCD where the voltages are represented as bars, so it takes 2 lines of 20bars to get a complete overview of a 40cell pack.
The other two lines could provide some other information if wanted.
The systems outside communication will probably be CAN based also so integration with the Vectrix dash showing particular cell-over/under voltages is planned, even without the extra LCD.
If anyone has other ideas let me know...