George Mitchell
New Member
- Joined
- Nov 2, 2020
- Messages
- 21
For three years now I have been successfully using multiple 12V LIFeP brands and architectures and different ages in one battery bank. At this point I have 6 100AH LiFePO4 batteries in parallel with no problems:
1) Constant Power w cylindrical cells
2) Relion w cylindrical cells
3) Weize w prismatic cells
4) Weize w prismatic cells
5) Renogy w pouch cells
6) Renogy w pouch cells
What really maters with this is that each of these batteries MUST have the SAME voltage requirements, including max voltage during charge and min voltage during discharge, and the same AH rating, That is essential.
Also essential to prevent disasters is for EACH battery to be fused directly from the positive terminal. The amperage of those fuses must just a bit higher than the maximum discharge from the bank divided by the number of batteries in the bank. These fuses are not for the purpose of protecting the battery they fuse, BUT to protect the rest of the batteries in the bank. This guarantees if any one battery shorts out due to failure, it will blow its on fuse thus not short circuiting the other batteries in the bank.
That said, this bank has experienced two failures recently that stemmed from external failures which were easily repaired. In each of those cases the BMS on each and every one of these 6 batteries functioned perfectly to protect the batteries themselves, very impressive and thus no sign of damage to the batteries. I simply connected the whole bank to two 20 Amp Renogy chargers and the BMS's reset and the bank eventially recharged to the proper voltage without problems. Due to the fact that the failures were caused be external components, I will post that issue seperately and explain the lessons learned in the process.
1) Constant Power w cylindrical cells
2) Relion w cylindrical cells
3) Weize w prismatic cells
4) Weize w prismatic cells
5) Renogy w pouch cells
6) Renogy w pouch cells
What really maters with this is that each of these batteries MUST have the SAME voltage requirements, including max voltage during charge and min voltage during discharge, and the same AH rating, That is essential.
Also essential to prevent disasters is for EACH battery to be fused directly from the positive terminal. The amperage of those fuses must just a bit higher than the maximum discharge from the bank divided by the number of batteries in the bank. These fuses are not for the purpose of protecting the battery they fuse, BUT to protect the rest of the batteries in the bank. This guarantees if any one battery shorts out due to failure, it will blow its on fuse thus not short circuiting the other batteries in the bank.
That said, this bank has experienced two failures recently that stemmed from external failures which were easily repaired. In each of those cases the BMS on each and every one of these 6 batteries functioned perfectly to protect the batteries themselves, very impressive and thus no sign of damage to the batteries. I simply connected the whole bank to two 20 Amp Renogy chargers and the BMS's reset and the bank eventially recharged to the proper voltage without problems. Due to the fact that the failures were caused be external components, I will post that issue seperately and explain the lessons learned in the process.