02-27-2019, 02:09 PM

Alright I have recorded 2711 cells in my spreadsheet and on my way to 3000 plus. Where it will end no one knows. It may not end at all although once I get my 14s200p wall built it will probably slow down some.

So I have been having fun with excel and have built a "Cell Calculator" that pulls data from my main sheet and filters it according to mAh per cell Then refilters to >80% capacity.

In other words enter the minimum mAh per cell required in your pack and it will spit out the results of how many cells that have been tested that have that result or greater. It also calculates the average mAhs of all the cells and then can multiply that by the number of p which will give you the Ah of that pack. You can adjust the max cell V, # of strings and then calculates the kWh of the whole pack.

So I did some scenarios with 2000mAh to 2300mAh entered.

I may change my mind now and go with as low as 2100mAh cells. First of I have a lot of 2200mAh rated cells that are testing at >80% of capacity mostly much better 90%+ but that is in the cutoff area of <2200mAh.

I have also added the IR calculations as a side benefit for those that are interested.

I can say this much as my IR investigation continues, I can just about guess what the capacity of a given cell is going to be just by the initial IR measurement alone. But I digress.

Here are the results of 2000mAh to 2300mAh pack calculations. Interesting to see that between the minimum per cell from 2000mAh to 2300mAh the total increase is only 1.73kWh.

So with this information would you reduce your cell requirements to 2000mAh or as I possibly plan to 2100mAh or would you hold out for the jackpot of all at least 2200mAh? I am itching to get started on my cell packs but I also want the best possible cells. So the dilemma continues.

Wolf

So I have been having fun with excel and have built a "Cell Calculator" that pulls data from my main sheet and filters it according to mAh per cell Then refilters to >80% capacity.

In other words enter the minimum mAh per cell required in your pack and it will spit out the results of how many cells that have been tested that have that result or greater. It also calculates the average mAhs of all the cells and then can multiply that by the number of p which will give you the Ah of that pack. You can adjust the max cell V, # of strings and then calculates the kWh of the whole pack.

So I did some scenarios with 2000mAh to 2300mAh entered.

I may change my mind now and go with as low as 2100mAh cells. First of I have a lot of 2200mAh rated cells that are testing at >80% of capacity mostly much better 90%+ but that is in the cutoff area of <2200mAh.

I have also added the IR calculations as a side benefit for those that are interested.

I can say this much as my IR investigation continues, I can just about guess what the capacity of a given cell is going to be just by the initial IR measurement alone. But I digress.

Here are the results of 2000mAh to 2300mAh pack calculations. Interesting to see that between the minimum per cell from 2000mAh to 2300mAh the total increase is only 1.73kWh.

So with this information would you reduce your cell requirements to 2000mAh or as I possibly plan to 2100mAh or would you hold out for the jackpot of all at least 2200mAh? I am itching to get started on my cell packs but I also want the best possible cells. So the dilemma continues.

Wolf

If 18 X 650 = 2200+mAh then we have power!

May all your Cells have an IR of 75mΩ or less

Last count as of 3/23/2019

Total Number of Cells 3743

Cells >80% of Capacity 2445

Cells <80% of Capacity 1265

Cells ≥2200mAh & ≥ 80% 1709

Google Drive for info https://drive.google.com/drive/folders/1...sp=sharing

Not your average Wolf

May all your Cells have an IR of 75mΩ or less

Last count as of 3/23/2019

Total Number of Cells 3743

Cells >80% of Capacity 2445

Cells <80% of Capacity 1265

Cells ≥2200mAh & ≥ 80% 1709

Google Drive for info https://drive.google.com/drive/folders/1...sp=sharing

Not your average Wolf