Help on choosing a touring battery setup

So I am about to build 2 ebikes for touring/bikepacking trips. One for myself and one for a friend. I plan on building the batteries myself since I have some 18650 cells and a spot welder. My target is 15-20mph cruising speed with rear hub motors and 52V batteries. Assuming I am using it correctly, at 20mph cruising with light (75W) pedaling, I will be using just over 6 battery amps according to the ebike simulator. So let's say 7A for a safety margin. Does this sound reasonable? I don't mind doing extra pedaling and reducing speed on the uphills.

Here are my cell counts:

NCR18650A - 190 cells
NCR18650GA - 144 cells
NCR18650B - 99 cells

Does it make sense to make 2 smaller batteries for each bike for redundancy, or 1 large battery each? I am leaning toward 2 smaller packs for each bike for safety in case one pack dies, as we may be many miles from home.

I am leaning towards this setup:

Bike 1: XL frame hardtail:
14s6p NCR18650A pack (~18AH)
14s6p NCR18650A pack (~18AH)

Bike 2: small frame hardtail:
14s5p NCR18650GA pack (~17AH)
14s5p NCR18650GA pack (~17AH)

Anyone of these packs should be able to deliver 7A continuous.

Does anyone have any thoughts or alternative suggestions? Thanks.

make 2 batteries from all the cells you have, 1 for each bike. no reason to spread it out over separate batteries. just spread all the cells of each type out evenly over each parralel group you make.

so a battery gets this number of each cell in every parralel group
:
190/2/14=6 cells A 2900mAh
144/2/14=5 cells GA 3350mAh
99/2/14=3 cells of B 3250mAh

so you end up with (6+5+3=) 14S14P battery for each of the bikes.

capacity will be:
6*2.9=17.4Ah
5*3.35=16.75Ah
3*3.25=9.75Ah
17.4+16.75+9.75=43.9Ah*3.6V= 158Wh*14=2.2Kwh

at 7A continus (that is 350W, wich is quite a bit) that would mean you could run 6,5 HOURS at full load.

that would also make this battery virturally bulletproof as its has an extremely light load on it.

Thanks for the input flippy. My concern is that finding a way to mount that much battery, especially on the small frame will be difficult. Especially if I still want space to carry other cargo. Since I wouldbe carrying a charger anyway, I figured I could carry less battery and just charge during a break.

Also, the NCR19650Bs and NCR18650As are lightly used cells. They have been tested for capacity and self discharge, but I don't have 100% confidence in them like I would for a new cell. That's why I was thinking of doing 2 packs / bike.

First figure out what the maximum is that you can fit. And buy a battery tester to do capacity tests on the used cells. We can help you distribute the cells.

First you need to figure out your limits. Bigger=better.

If you can carry 2 small ones you can also carry 1 big one. Or split the battery in 2 sections to distribute the weight. that is also not a problem. if you already carry the battery with you there is no reason to not have it hooked up.

transposon said:

My concern is that finding a way to mount that much battery, especially on the small frame will be difficult. Especially if I still want space to carry other cargo. Since I wouldbe carrying a charger anyway, I figured I could carry less battery and just charge during a break.

Also, the NCR19650Bs and NCR18650As are lightly used cells. They have been tested for capacity and self discharge, but I don't have 100% confidence in them like I would for a new cell. That's why I was thinking of doing 2 packs / bike.

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Sorry, have to agree with Flippy on this one -- his advice is spot on in this case.