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What happens if 1 cell dies? :confused:
#1
I have 7S5P Pack and 1 cell died on 3rd string 2nd Parallel and blown the fuse i haven't change it yet. does it mean my battery pack is working as reduced capacity 7S4P pack? or does the pack work as 7S5P but reduced capacity in 2nd Parallel?
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#2
The 4P string will be putting out 25% more Amps per cell and will cycle deeper depending on what the state of charge of the whole pack was when the fuse blew. Overall, the pack will charge and discharge based on the voltage parameters you set, and that will be triggered by the 4P pack as it will have the least total capacity. So 6 strings will act like 5P, but the 4P string will reduce the capacity of the whole pack.

Let's say the fuse blew when all strings were at 3.0V (0%). When you charge the pack (without balancing), charge will terminate when the 4P pack reaches 4.2V (100%), but the other strings will be at 3.9V (80%). That's an example, not necessarily what your pack is set up for.
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#3
The "Parallel" with the smallest capacity defines the overall capacity of the pack. Means it will be empty first, while all other still have some charge.

How did you find one cell died ?
1 kWp in Test
4 kWh battery target - plus Mobile Home battery
Ultra low cost
Electronics ? No clue. Am machinery engineer.
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#4
All though im new to building packs my assumption is (correct me if im wrong). The cells in "parallel" with the blown fuse will have overall smaller capacity and affects the overall capacity of the entire pack it means that if you discharge the pack, the cells in "parallel" with the damaged cell will have the lowest voltage and if you charge it you will find the highest voltage. you can check for the voltage if you have a multi meter or cell meter.
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#5
(04-21-2019, 07:13 PM)rhedbatt Wrote: All though im new to building packs my assumption is (correct me if im wrong). The cells in "parallel" with the blown fuse will have overall smaller capacity and affects the overall capacity of the entire pack it means that if you discharge the pack, the cells in "parallel" with the damaged cell will have the lowest voltage and if you charge it you will find the highest voltage. you can check for the voltage if you have a multi meter or cell meter.

Exactly.
1 kWp in Test
4 kWh battery target - plus Mobile Home battery
Ultra low cost
Electronics ? No clue. Am machinery engineer.
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