New option for repackr


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Oberfail

Member
Joined
Jun 22, 2021
Messages
241
When i'm copying my cells capacity out of excel and put it into repackr, each capacity will be seperated from each other.
When put them into your tool, i get one long number out of them, making your tool unusable for me.

Repackr also has no issues, with wrong data like this:

2081
dead
dead
2319
1981 H
1970
2349
Using my bad sample data to build a pack, results in wrong numbers for the capacity.
I'm not good in maths, but wouldnt divergence be twice the number it currently is?
1637609875216.png
 
Last edited:

jhooton

New member
Joined
Nov 18, 2021
Messages
3
Using my bad sample data to build a pack, results in wrong numbers for the capacity.
I'm not good in maths, but wouldnt divergence be twice the number it currently is?
View attachment 26507
Hey have those changes made, amp hours and watt hours should be fixed.

The divergence is a +- value due to it being a range. The highest series group will be 134 above the average mAh capacity of a group and the lowest capacity series group would be 134mAh below that average capacity value.

If it would make more sense, we could swap to using just the entire number rather than a +- value.

Just let me know!

I also found one more bug around leftovers that I'm working on fixing now.
 

Oberfail

Member
Joined
Jun 22, 2021
Messages
241
I think the whole number would make more sense, because in the end you're missing out on 268mAh which in this example is already nearly 2.5Wh.
 

Kakakee

New member
Joined
Jul 16, 2021
Messages
25
I think the whole number would make more sense, because in the end you're missing out on 268mAh which in this example is already nearly 2.5Wh.
Jeff and I agree too, we spoke about it and added the change to our to-do list for this week.
 

Kakakee

New member
Joined
Jul 16, 2021
Messages
25
I think the whole number would make more sense, because in the end you're missing out on 268mAh which in this example is already nearly 2.5Wh.
Just wanted to let you know, the change has been made. Working on a few more changes/improvements which should be released in Early December. Thank you for your feedback!!
 

Kakakee

New member
Joined
Jul 16, 2021
Messages
25
The IR balancing functionality has now been added to our packer tool!!

Please let us know if you catch any bugs or errors, thank you all again for your support!
 

frankonline

New member
Joined
Apr 28, 2022
Messages
2
The IR balancing functionality has now been added to our packer tool!!

Please let us know if you catch any bugs or errors, thank you all again for your support!
Can you tell me how this tool calculate the parallel string average IR? Can you share the fomula with us?
 

frankonline

New member
Joined
Apr 28, 2022
Messages
2



@frankonline

Not sure how @Kakakee website does it but there are many tutorials on this.
The basic mathematical formula is as such:

Wolf

View attachment 27383
Also a bunch of videos explaining.
https://www.youtube.com/results?search_query=calculating+parallel+resistance
Hi, Thanks for the explanation. I just put some test data (1000:10,1100:20,1000:30,1100:40) into the tool and checked the outcome. It just tells the avarage of IR values but not showing the actual parallel resistance of the specific cell set. 40miliohms and 10miliohms should create 8miliohms parallel resistance but the tool just shows the avarage of two values. I just need to know that is it using the IR values to suggest the best possible combination or just based on the capacity balancing between parallel sets.

Thanks.
 

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Wolf

Active member
Joined
Sep 25, 2018
Messages
1,693
@frankonline

Not sure how the web site calculates all this.
I personally prefer to run a tight criteria when building a pack/battery. If using a combination of cells from different manufactures i.e. Frankenstein battery I keep the chemistry the same as in ICR possible some NCA (Hybrids) mAh to a max deviation between low and high to ≈400mAh. Also the AC IR I keep ≈15 mΩ max deviation give or take a mΩ. Usually for good cells "ICR" especially "Frankensteins" in my experience mAh tested results in the SOH of ≈85% the mΩ is usually between 40mΩ to 55mΩ. Also I use an excel based repackr that I can import my test cell data directly into.
If you go with INR cells (Note: I would not mix ICR and INR chemistries) the same applies but the AC IR should probably be a lot tighter maybe ≈5mΩ.
So I would make sure whatever chemistries you are using keep your IR and mAh within these tolerances if possible and you will build a successful pack and battery
I have explained a lot of this with research data in my posts on IR
Wolf
 
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