elkooo
Member
- Joined
- Aug 9, 2019
- Messages
- 32
Hi
I don't want to spend 1K$ for a Batrium. So I decided to do my own BMS. I already have some Ideas how I would like to solve it on the hardware side (see schematics conceptenclosed).
The CPU unit will be an ATmega.
It will measure each cell in cycles. To overcome common-ground-issues, I will do this by charging a capacitor and measure its voltage. This can be done by connecting the capacitor with two reed-relays to each of the cells in cycles. It balances its Voltage to the cell voltage very quickly, is then disconnected from the cells an connected to the CPU to measure its Voltage.
If one cell block is high by a defined amount against the other blocks, another relay triggers the discharge unit for a defined amount of time / measuring cycles to drain some power from it until it is equalized again.
Low voltage cutoff and so on can all be controlled by the CPU and are matter of programming.
Let me know what you think about it. I am also happy to hear your opinion on thechoice of components (or where I didn't yet choose, let me know if you have a proposal... MOSFET...)since I don't have a lot of electronics experience just now. Still learning
Cheers,
elkooo
I don't want to spend 1K$ for a Batrium. So I decided to do my own BMS. I already have some Ideas how I would like to solve it on the hardware side (see schematics conceptenclosed).
The CPU unit will be an ATmega.
It will measure each cell in cycles. To overcome common-ground-issues, I will do this by charging a capacitor and measure its voltage. This can be done by connecting the capacitor with two reed-relays to each of the cells in cycles. It balances its Voltage to the cell voltage very quickly, is then disconnected from the cells an connected to the CPU to measure its Voltage.
If one cell block is high by a defined amount against the other blocks, another relay triggers the discharge unit for a defined amount of time / measuring cycles to drain some power from it until it is equalized again.
Low voltage cutoff and so on can all be controlled by the CPU and are matter of programming.
Let me know what you think about it. I am also happy to hear your opinion on thechoice of components (or where I didn't yet choose, let me know if you have a proposal... MOSFET...)since I don't have a lot of electronics experience just now. Still learning
Cheers,
elkooo