DYI battery pack, used cells, how to deploy varying capacities?

[Dave Hutson]

I am in the process of scavenging use 18650 cells for a 52V battery pack, my cells vary from 1800mah to 2200mah being new to this I was wondering is there a preferred way to distribute cells of varying capacities or just mixing them willy-nilly is as good as any?

Also will your capacity only be as high as the lowest battery in that particular cell?

 

[JRA]

You really need to go to Endless Sphere with regards to information about that. There are people here that do some battery construction but there are way more there and threads already that you can probably search to find your answers. Personally I wouldn't use used mixed mah batteries to build a pack to begin with.

 

[Dave Hutson]

I am building this pack from used laptop batteries, this is a 1st battery build more or less a testbed. This battery will be used for nonperformance required, Trips around town etc. something to use and abuse for learning experience. I did get some information concerning distribution of the cells which makes perfectly good sense to me.
The method used is to line your cells up from highest capacity to lowest as you build each cell of the battery take one of the highest one of the lowest for your 1st cell do this until you have enough cells for the 1st cell then repeat for all remaining cells. This should distribute capacities amongst the various cells of the battery for the most uniform result.

 

[Ravi Kempaiah]

I am building this pack from used laptop batteries, this is a 1st battery build more or less a testbed. This battery will be used for nonperformance required, Trips around town etc. something to use and abuse for learning experience. I did get some information concerning distribution of the cells which makes perfectly good sense to me.
The method used is to line your cells up from highest capacity to lowest as you build each cell of the battery take one of the highest one of the lowest for your 1st cell do this until you have enough cells for the 1st cell then repeat for all remaining cells. This should distribute capacities amongst the various cells of the battery for the most uniform result.

Without a sophisticated BMS, stacking up cells of different capacities would not be a good idea.
You could get some Samsung 29E cells for really cheap and will save you lot of hassle down the road.

 

[flymeaway]

being new to this

!!! You are literally playing with fire. If you use mismatched cells, or one cell is defective in the pack you could have a serious failure resulting in a catastrophe.

Court J .

 

[Longtaich Battery Welder]

You really need to go to Endless Sphere with regards to information about that. There are people here that do some battery construction but there are way more there and threads already that you can probably search to find your answers. Personally I wouldn't use used mixed mah batteries to build a pack to begin with.

Yew, I think it is better to use all the new batteries bo build a pack. Also need few battery testing meters to check the capacity and resistance, voltage, etc.