I have seen several successful mods adding supplemental battery power to Bionx bikes. I have also seen a build powered by Dewalt 36v packs. I like the Dewalt pack simplicity plus i own a cabinet shop so the Dewalt powered bike would be kinda cool in the showroom.
Can I use the Dewalt packs for my Bionx supplements? My plan would be to supply the supplemental power through the factory charge port. My question is would i need multiple packs in series or would just one at a time be ok? I believe the voltage is close enough, but not sure about amperage.

Don't the dewalt packs come with their own BMS (battery management system)? Then yeah, you could probably run a bike off of just one dewalt 36v pack. It's a 36v 2.5 AH pack from what I understand and the cells on them are the best on the market. They are actually A123 lifepo4 cells with nanotechnology. You could probably go about 6 or 7 miles maybe on one pack. With the bionx, though, maybe even farther, maybe even 10 miles especially if you pedal. As far as hooking it up, you'll have to do some research because I heard that bionx has made it difficult to do that kind of thing.

You should look into the C rating of the A123 cells, though and make sure you aren't discharging a current greater than it can handle. I think the A123 cells can handle quite a bit of current, though.

So if you had a 20 amp controller, the cells would have to be capable of about 9C I think. Yeah, so you might need 2 or 3 packs so you don't fry the packs. So if you had 2 dewalt packs...it'd be 36v 5AH so you'd need the pack to be capable of a 4C discharge if you use a 20 amp controller. I'm looking up right now what the C rating is on each pack

This says that A123 cells have a 30C discharge C rating which is awesome so yeah you should be able to run your bike off of one pack. As long as the BMS circuit board on the pack allows that kind of a discharge current. This says 30C rating for A123 cells. So if it's 30C then each 36v2.5AH pack should be capable of about 60 amps discharge current, definitely above the needed 20 amp of your controller or whatever you are using.

https://www.flyelectric.ukgateway.net/lithium-a123.htm

If you want to use DeWalt battery packs without disassembling the case and reconfiguring individual cells, you'll need to look for kfong's interface board. Check the Endless Sphere forums to see if they're still available. If not, you're going to need to disassemble the battery case and build a new battery out of the cells, dumping the DeWalt BMS. As far as using only one 36V DeWalt, most of the early adopters who went the intact DeWalt battery pack with interface board ended up paralleling multiple packs--one pack gets about 3 miles on flat terrain. You might post your question in Endless Sphere and V is for Voltage. There are many Bionx owners on V is for Voltage so you might start there. Good luck.