3.2v cell ah preference

[G00SE]

I did a cursory search of current 3.2v cell prices/inventories in stateside warehouses as well as freight. It seems that many sizes are at a comparable $/ah price at the moment so I became curious.

If prices were equivalent for each, what drives or drove you to a certain cell vs another? Say, 160ah, 230, 280, or 304. Or are you not picky? Maybe Physical size constraints and terminal type?

 

[Quattrohead]

280's were the best price per ah.

 

[littleharbor2]

I went with 230's because my 2p8s configuration gave me the desired 460 ah. rating I wanted.

 

[Rednecktek]

304's for my systems now that they're cost competative. If I gotta build a battery anyways I want the most capacity I can get all at one time.

 

[Craig]

Bigger or in the case of cells more storage is better I dont think I have ever said gee i wish I had less capacity. So I would buy the biggest ones I could afford. Although there is replacement cost if one cell goes bad.

 

[G00SE]

Bigger or in the case of cells more storage is better I dont think I have ever said gee i wish I had less capacity. So I would buy the biggest ones I could afford. Although there is replacement cost if one cell goes bad.

I track with that, but I’ve also seen threads where someone made a cell choice of one vs the other due to the height being physically shorter. Allowing him to fit in his rack. I figured there may be some design element at play otherwise everyone would probably just spring for the biggest they can get their hands on

 

[Rednecktek]

My understanding was that the 280's and 304's are the same size, it seemed like it making my packs.

 

[Alkaline]

go for the most capacity for the size instead of paralleling batteries. Steve_S said recently they are coming out with 400 and 500AH cells which will be even better (the C rate will probably go down though).

 

[OffGridInTheCity]

The other thing to think about is expansion over the coming years - if you expand (add more 16s batteries) do you want them to be similar ah. In my case, I just added my 9th battery in year 5 of operation and I'm working on on #10 and #11 and all are 260ah. My point is that you might want to pick a common size / likely available long term that you're comfortable with in terms of multi-year expansion. Not a huge deal but perhaps a check box item for the overall list.

 

[G00SE]

go for the most capacity for the size instead of paralleling batteries. Steve_S said recently they are coming out with 400 and 500AH cells which will be even better (the C rate will probably go down though).

My goal is ~800ah/40kwh
Napkin math says 1-16s 304ah is 15.5kwh, 280ah is 14.3, 230ah is 11.8, 160ah is 8.2.
Which would seem to imply I’d need to acquire 48 of the 280 or 304.
48 230s would net me 35kwh whereas 64 would be 47.
However, 80 160s would net 41kwh and 128 100s would net 41kwh as well

My objective was to simply go the route of whichever had the overall least cost, should I focus on something other than cost if all perform similarly in the end?

 

[Alkaline]

3 strings of 16s parallel of 280 or 304 would be ideal and give you the 40KW you are needing.