Redbeardbeer
New Member
- Joined
- Nov 7, 2021
- Messages
- 25
Hi all.
I'm now back to square 1 trying to design my powerwall/battery.
First rendition was to make 16P 'bricks' and connect these in series to make a 14S16P.
If I want to add more capacity, I have to add another 14 packs of 16 cells and parallel them together.
BMS balance leads (using small 7.5amp wire) would be attached to each paralleled set of 'bricks'.
Second rendition was to have bricks of 14 cells in a 14S1P configuration with a common main positive and main negative busbar.
This was much easier to expand capacity as I can just add 14S1P bricks in parallel to the main busbar.
I had planned on putting a 14 pin connector onto each of the 14S1P packs, and creating a 14 pin busbar that would connect these to the BMS would balance each 'cell' across the battery - i.e. cell 1 would be cell 1 on brick 1 and cell 1 on brick 2 etc etc.
BUT - I didn't think about the fact that I would be essentially joining all the cell 1's, 2's, 3's etc across the bricks together by small 7.5amp balance wire....which would be bad as I assume this could cause a lot of current to flow from one cell to another via the balance lead?
Can anyone suggest a design solution that allows me to have a BMS monitor/balance the pack, while allowing modular expansion (and the ability to take a brick out if needed for maintenance without killing the battery)?
Thanks
Hunt
I'm now back to square 1 trying to design my powerwall/battery.
First rendition was to make 16P 'bricks' and connect these in series to make a 14S16P.
If I want to add more capacity, I have to add another 14 packs of 16 cells and parallel them together.
BMS balance leads (using small 7.5amp wire) would be attached to each paralleled set of 'bricks'.
Second rendition was to have bricks of 14 cells in a 14S1P configuration with a common main positive and main negative busbar.
This was much easier to expand capacity as I can just add 14S1P bricks in parallel to the main busbar.
I had planned on putting a 14 pin connector onto each of the 14S1P packs, and creating a 14 pin busbar that would connect these to the BMS would balance each 'cell' across the battery - i.e. cell 1 would be cell 1 on brick 1 and cell 1 on brick 2 etc etc.
BUT - I didn't think about the fact that I would be essentially joining all the cell 1's, 2's, 3's etc across the bricks together by small 7.5amp balance wire....which would be bad as I assume this could cause a lot of current to flow from one cell to another via the balance lead?
Can anyone suggest a design solution that allows me to have a BMS monitor/balance the pack, while allowing modular expansion (and the ability to take a brick out if needed for maintenance without killing the battery)?
Thanks
Hunt