build advice

[jssneptune]

Hi,
After spending time reviewing posts I have decided to build one of my own.
As it would only be fun if i do it myself I purchased some parts.
I am an industrial electrician at a steel mill so it is perfect for me. I ride and own many bikes.
Here's what i'm working with.
my old 2001 trek fuel 98 full suspension. its in great shape.
Banfang 36v 500 watt CST motor. Aliexpress
36 hole Rhyno lite rim. Bikes for life.
9 spd cassette.
36-72 volt 25 amp controller. Grin tech C7225-NC
spokes Grin tech
Battery :
I have 9 20v ryobi drill packs. with one left over. Samsung 2000Mah cells. New @ home depot. Cost= 90x5 =450 plus ca tax. Well that added up fast. LOL.
I have dissembled them and am in the process of making 3- 5s6p packs with balance leads.
Planning on running these 3 packs in series so 3.7 x 5 = 18.5 x 3=55.5v @ 12000mAH.
I own 4 hobbie chargers 3 are the same turnigy charger so for now charge and balance with those.
I would like to bulk charge also but cannot find a suitable way. mostly because of safety concerns.
Misc parts . Brake cutoff , throttle ect.
This will be a commute bike on flat terrain. I really want to use the batteries as 5s x 3 because they are all soldered up with nice tabs from the disassembled packs.
At this point I will take any advice the forum has to offer.
Thanks in advance
Jeff S.

 

[motomech]

I assume you mean 3S/3p to get 12000 mAh.
The 6-FET controller may get pretty hot with that relatively high wind motor, especially climbing.
Some may advise you you need a higher rated controller, but I have used the C7225-NC and saw spikes of 28 to 29 Amps on the CA.
The Infineons are strong performers for their size, just noisey.
Speaking of CA's, a CA-DP would be an obvious add-on, just a matter of budget I suspose.
At least your batteries will have their own LVC, so you don't need a CA for that.
I have an older CA I don't use anymore. It was great for learning, but these days, I just pedal along on the same routes, so I really don't need extra info. And I use controllers with hard LVC's or in the case of my Infineon, a Voltmeter..

The Ebike CA sim has your bike topping out at 29 to 30 Mph. Plenty fast enough, I.M.O.

 

[Drunkskunk]

I thought those packs were 2000mAh, which would make 9 packs into a 3s X 3p setup, 55.5volts, 6Ah.

Otherwise, looks ok. I'd go with a higher power controller personally, like the C3635, then tame it back with a Cycle Analyst to around 30 amps. Better heat dissipation, and a little more power from the motor for $5 over the cost of the other controller.

You really want a Cycle Analyst. It is the most useful Ebike tool ever.

Also, Just be sure to put a set of torque arms on it. That Bafang can make more torque at the shaft than most dropouts can handle unsupported. Grin Tech is the best source for those as well.

 

[USAEBIKECO]

Be sure to invest in thick Kevlar tires and puncture resistant tire tubes.

Don't go cheap on the tires because getting stranded with an ebike is not fun.

 

[dogman dan]

Ow, shoulda talked here first before the battery purchase.

But everything else sounds like sound decisions.

 

[jssneptune]

Thanks everyone.