Hello All,
I am looking into embarking on a DIY powerwall project and want to get some opinions/input from people with experience/knowledge. The rough outline of what I have in my head at the moment is the following:
I am a little concerned about the connection resistance of the snap in battery holders, but since it will more than likely use fairly low C rates, that may not be a big issue. Also, I am thinking the price might not be super cheap. I am ballparking $100-150 per module with cells. The features/cool factor/fun factor might be worth it though. I do like the idea of being able to identify/replace misbehaving cells really easily. I see these giant battery packs online with tons of cells in parallel with at best one temperature sensor for the group. Good luck identifying a bad cell in the mix and have fun replacing it.
Well... enough babbling. Let me know if you guys have any ideas or suggestions. Thanks.
I am looking into embarking on a DIY powerwall project and want to get some opinions/input from people with experience/knowledge. The rough outline of what I have in my head at the moment is the following:
- PCB based
- 48V system using LiFePO4 cells in 16s1or2p, or lithium ion 14s1or2p, leaning toward 26650 16s2p LiFePO4
- each board with built in BMS using something like this IC: BQ769142PFBR
- temperature for each cell using something like this IC: TMP1075DSGR
- using a low power consumption microcontroller like this: CC2640R2LRHBR with zigbee or similar communication or using a simpler arduino compatible microcontroller that you can check/configure with a USB connection to a computer.
- onboard current sensing/power monitoring per module
- onboard configurable current limiting for charge/discharge
I am a little concerned about the connection resistance of the snap in battery holders, but since it will more than likely use fairly low C rates, that may not be a big issue. Also, I am thinking the price might not be super cheap. I am ballparking $100-150 per module with cells. The features/cool factor/fun factor might be worth it though. I do like the idea of being able to identify/replace misbehaving cells really easily. I see these giant battery packs online with tons of cells in parallel with at best one temperature sensor for the group. Good luck identifying a bad cell in the mix and have fun replacing it.
Well... enough babbling. Let me know if you guys have any ideas or suggestions. Thanks.