tsourorf
1 mW
- Joined
- Jan 29, 2016
- Messages
- 19
Oh, that was for that pack? I hate to say but you've missed a few things there.
First of all, the 20mOhm IR is rather optimistic but I wouldn't care about it as it doesn't affect the differences between cell current contributions anyway.
The most important thing is that you haven't put any resistors for the nickel connecting the 7 cell row. I don't know the thickness of that, so, I wouldn't suggest a number for the resistance to put between them.
Then, there is the copper wire resistance. It's 1mm wide. That makes the surface approximately 3.14mm2 which, according to the known Matador table gives us roughly 5.3mOhm per meter. That translates to 95.4uOhm for the sections you have 40uOhm. Then, there are the lengths or copper at the end... From the pictures, I can see that the middle wire is approximately 15mm long and the side wires (until they reach the first cell) are approximately 15+18=33mm long. I would use 80uOhm for the middle section and 175uOhm for the side ones.
I'll be honest, I haven't changed your model to include the things above, so, I don't know what the impact would be. All in all, I expect a small change in the variance of cell current contribution but, because of the use of copper, I wouldn't expect any huge differences.
First of all, the 20mOhm IR is rather optimistic but I wouldn't care about it as it doesn't affect the differences between cell current contributions anyway.
The most important thing is that you haven't put any resistors for the nickel connecting the 7 cell row. I don't know the thickness of that, so, I wouldn't suggest a number for the resistance to put between them.
Then, there is the copper wire resistance. It's 1mm wide. That makes the surface approximately 3.14mm2 which, according to the known Matador table gives us roughly 5.3mOhm per meter. That translates to 95.4uOhm for the sections you have 40uOhm. Then, there are the lengths or copper at the end... From the pictures, I can see that the middle wire is approximately 15mm long and the side wires (until they reach the first cell) are approximately 15+18=33mm long. I would use 80uOhm for the middle section and 175uOhm for the side ones.
I'll be honest, I haven't changed your model to include the things above, so, I don't know what the impact would be. All in all, I expect a small change in the variance of cell current contribution but, because of the use of copper, I wouldn't expect any huge differences.