I provided access to the 15 amp fused connection. This goes directly to the negative side of the battery. The other side of the enable pin goes directly to the positive side of the battery. You could create a charger with protection diodes to charge each pack individually. Since you don't know the state of charge each pack has, you need to keep them all isolated, since one pack could try to charge another and create large currents that could do some damage. One solution to this is to protect the packs with a 5 amp fuse on the charge connects to all the batteries. Then if you want to charge all the packs together, provided they were closed to each packs capacity, meaning youÃ¢â‚¬â„¢ve been keeping all packs charged and discharged together. You can parallel them all together at the end of each run. The fuse will blow if one pack is significantly different from another protecting each individual pack. If there is a slight difference, the 5 amp fuse should be easily handled by the batteries. Now you have all packs in parallel with your fuse charge cable and can charge them with one charger.
Here is a schematic of the charge cable,
It might even be possible to leave this cable connected in the bike all the time as long as you keep all the packs together. I'm not sure how the BMS will handle this, but I suspect it will be ok with it. Then all you have is one connector to deal with. I don't advise this since I have not tested this out and don't plan too since I will be using packs in 2, 4 or 6 depending on my ride distance so the packs might not be the same at times. I will be using 2 packs most of the time since everything is so close, so the 1 hour dewalt charger is ideal for me. A drawback to leaving it installed all the time is one bad bms could take out the rest of the packs. Safer just to use an external charge cable and connect them together with some mutipin connnector.
I've been quite happy with the dewalt bms setup. IÃ¢â‚¬â„¢m just running 2 packs till I get the bike finally wired. I had a nice late night ride last night to cool off from the dayÃ¢â‚¬â„¢s 90 deg heat and rode the packs to empty. I was close to home and just pedaled the rest of the way. I donÃ¢â‚¬â„¢t have a lighted wattmeter and itÃ¢â‚¬â„¢s a distraction to have to worry about the batteries anyways. Great just to enjoy the ride and let the batteries take care of themselves.
Good link, so you don't over do it with wiring size. Just follow chassis wiring guidlines.