DIY joining Batteries, AWG, amperage etc

[peteuk84]

Hi ppl i have 4 banks of 7s2p batteries inside x15 battery plastic holders.
rather then have to rip them apart and spot weld, which i could do
I want to just wire them up to 58.8 v with a 14s bms and fit into a ply box on bike.,
two of each are already wired together using 18awg as they come from two 28v 9ah identical packs with only 13 cycles, the 28v outputs on these batteries are only 18awg also.

The batteries are panasonic cgr18650cg 2250.
my ebike is a 250w bafang, 350w 16-18a controller.
lots of hills hear me i dont want a bottle neck or something to get hot.

Do I need to upgrade those 18awg wires if i want to join these two battery's/four banks,? I have some 16awg here but would need to get some bigger stuff ordered now if i do.
And am i missing anything else.
Thankyou.

 

[taserface]

Looks like they are rated at 6a discharge continuous. Figure 4-5a to err on the safe side.
A 14s4p should be good for 16-20a continuous. At 52v nominal that would be 800-1000w and 250w would be roughly 5a continuous draw.

For short runs, I think 18awg wire should likely be okay and I think 16awg should be totally fine, but if it was me and I wanted to to be completely confident nothing would get warm or was a potential bottleneck, I might go with 14. Though, FWIW, IIRC XT-30a connectors are usually paired with 16awg.

If the motor stays in the 250w-500w range, 18awg should be able to handle 5-10a just fine (especially for shorter/peak bursts).

Side note: I don't know how these will be wired up, but if you are planning any soldering... use caution. If you have a spot welder and need to solder something to the cells, solder the wire to a nickel strip first and then (after it has cooled) spot weld the nickel to the battery.