TerraTrike e-power conversion is done!

[pullin-gs]

****4/20/2019 Update***
Joined the 500 mile club yesterday!
Got weight down to 49lbs....increased stealthyness by hiding wiring and put controller is inside seat....still rides fast when I ride without battery.

****11/2021 Update***
Joined the 4000 mile club!
Dumped light Bix-power 36V 11AH pack for 44V 8AH pouch pack 18 months ago.
Wore out Marathon tires...replaced with new Marathons.

******************************Original Post*************
Bike is done! I have been riding for a week now and am ready to share results.
This is my 2nd e-build conversion (1st was an e-powered kayak over summer....excellent results BTW).
Project goal was to build a 500W 15MPH-max trike for leasure rides around town and on trails. I wanted 15 mile minimum range.
Anyway, here are the components I settled on:
---------------
-Donor Trike-----$500
Stock Terra-Trike Tour-II w/20" wheels...got a great deal on it used in new condition.
-Motor------------$150
Q128C 36V 328RPM hub motor (bought only the motor)
https://bmsbattery.com/ebike-kit/768-16765-q128c-135mm-500w-rear-driving-ebike-hub-motor-ebike-kit.html
-Wheel Rim-------$20
Built wheel from a crystal-lite 20" 36-spoke rim
https://www.ebay.com/itm/Crystalyte-20-Custom-Bicycle-Rim-Bike-36h-12g-Heavy-Duty-Ebike-Hub-Motor-SILVER/123586108016?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
-Custom Wheel Spokes---$27
Laced wheel with 13G spokes (5mm nipples)
https://www.ebay.com/itm/36-Custom-length-13g-2-3mm-Silver-spokes-with-nipples-for-Electric-bicycles/263804534171?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
-Controller------$19 off Amazon
Brainpower Sine-Wave (not!....I scoped it) KSDLM25 1000W Controller
https://www.ebay.com/itm/New-36V-48V-1000W-38A-E-bike-Vehicle-Scooter-Brushless-Motor-Speed-Controller-US/382610841757?hash=item591562209d:g:Z6sAAOSwHGxb161A:rk:1f:1&frcectupt=true&autorefresh=true
-Battery Pack------$56 for cells-
-Another $15 for aluminum stock I used for cell-tab clamps and stainless clamp screws
36V 8AH pack....homemade 10S 8AH LIPO pack. Used below cells (deal made TWO packs!!!)
https://www.ebay.com/itm/20-SPIM08HP-3-7V-8AH-LITHIUM-POLYMER-BATTERIES-25C-200A-SUPER-CELLS-24V-36V-48V/173305036284?hash=item2859c8fdfc:g:QXIAAOSw8~5a72gx:sc:FedExHomeDelivery!34442!US!-1:rk:2f:1&frcectupt=true
-Other----$30---throttle, 20-amp switch, cheap bike computer, 12AWG copper wire, shrink, etc.
All-in price for conversion is less than $350.
Very fun build. I laced my own wheel, built my own pack, and engineered total solution.
Fused at 20amps. Contoller dialed in for sensored operation.
I used a "twist" type throttle.

Results:
I have about 50 miles on it. No issues so far. Top speed is 17MPH. Top speed over 22MPH if controller set to "fast"
Moter is wisper quiet! I was at least expecting a noticable wine or commutation noise. No noise! Very nice.
Battery is good for about 15-20 no-pedal miles depending on hills I travel. My wife gets over 40 miles because she keeps it under 12MPH and pedals some. Feels like a go-cart in the tight curves of local winding bike paths that go through woods.
I built my own wheel....laced it with a 7mm offset so rim would be at center of frame (8-speed cassette puts it off-center by defult). Excellent results with the wheel...I had a little bit of a learning curve to get things figured out, but in the end I got it right the first time around.
Builid is very light also. Trike is 38-lbs, battery/bag is 10-lbs, motor about 6-lbs, controller is about a pound.
I selected a gear-drive motor that free-wheels. Initially motor freewheel seemed like there was a lot of resistance. However after 10 miles or so things losened up. Initial resistance caused by tight new rubber seals. Can pedal all day and not notice motor. Very happy with this motor. I hope it holds up. There is not much information on it here.





View attachment 1



Build issues:
Motor RPM (KV is 11-ish) is MUCH HIGHER than vendor clamed 328RPM...actual is 420 RPM at 36V full throttle. That is too fast for my planned build! Fortunately the controller has "three-speed" switchable options. When I set it to slow speed, RPM comes down to my target speed.
LIPO pack builds are always a pain. Coming up with a safe way to connect cell tabs and manage charge/discharge took some time. But in the end all was good. I decided to "monitor" each cell voltage (vs use a BMS) which alarms when any cell voltage goes over 4.2V or under 3.0v. I use a lab power supply to charge to 41.0 volts @3.0amps. I will replace this battery with a much lighter Bix-Power 36V 11.6AH....uses panasonic NCR18650PF 2900 cells. Price is about $350 shipped.
For now battery gets stored outside of house with my 3S3P kayak battery (made from same cells).

Things I need to do still:
Clean things up.
Install new Bix-Power battery (5 lbs lighter!) that uses safer LION cylinder cells and more advanced electronics.
Maybe update throttle?.....maybe not...I kind of like what I pulled from parts box...it feels really good.
Tires are low-pressure (40lb) stock tires....my other trike (same model) uses 80-lb tires.

 

[pullin-gs]

Other pictures....
View attachment 2
View attachment 1

 

[dankcmo]

Thanks for the details and photos of the build. Just purchased a TerraTrike Rambler N38 and looking to add electric "Assist" for hills with limited speed much as you have described. Have always enjoy DIY project benefits of both cost savings and the detailed knowledge gained from research and working through problems with the build. Originally I had discounted a wheel drive due to the weight and been back but after researching this forum and reading post like yours, think I'm slowly working my way through the swamp of options.

Will review your motor selection and maybe look at 18650 battery build option. I only have a 30vdc bench power supply and would prefer to buy a dedicated charger to monitor the cells. Do you you have any suggestions?

Building the wheel is something I've wanted to do but never had a reason to another puddle to jump into and another tool for the garage. Always a good thing right?

Thanks again for the post and look forward to updates.

 

[pullin-gs]

Suggestions:
I would consider a dedicated 36V or 48V charger....they are much less expensive and purpose-built.
Look into gear-drive hub motor options. They are much lighter and stealthier than heavier more powerful direct drive motors.
I really like 500 watts....its a nice compromise between wimpy 250 and heavier 1000w setups.

I liked the results of this build so much that I did my wife's TerraTrike also. For hers, I went with the same motor/controller/rim/spokes, but this time I purchased a quality Bix-Power e-bike 36V battery. It came with a charger.

The battery cost more ($350) than all the other components combined!

 

[dankcmo]

Yes, I'm definitely ordering the gear hub and the Bix-Power battery this evening. Have the Rim and Spokes on the way and will be using a 100 psi tire. I do like the Bix-P battery specs though I had planned to build up an 18650 block but have wisely backed on that to get this conversion done first and put on a few miles.

Would you consider the following charger?
https://www.bixpower.com/product-p/acc-36500.htm

Overall, I'm happy with the total pricing, even with the Bix-P battery and charger option. It's still less than 1/2 what I had expected to spend and is another $800 less that a shop would provide.

The only concern I have is the controller, that cost is amazing and as I have not experience with these, I am concerned with a short life, ending on a hill 10 miles from home. But again, this is a learning project and upgrades are expected and welcome down the road. I appreciate your resistor modification and will check it out on the bench test of the system.

 

[dankcmo]

Well those who snooze loose, and $$ more. Ordered the Q128C 36v motor (cost up $190 w/ shipping) and missed out on the now discontinued $19 Sinewave controller. Brain Power has move to 350, 410 then up to 1500mA. I'm trying to get more info from BMS on their controllers and LED's. One controller listed as Sinewave, rest are listed as Torque. Can get additional components, throttle sensors available from them as well.

Bix Battery is due on Monday so will spend some quality time finding the best mounting location and looking at cabling.

Did you wire in an ON/Off switch? I didn't see one on the battery pack.

 

[pullin-gs]

My original battery pack has a home-depot toggle switch (rated for 25 amps @120vac....current much higher for swiches when used w/dc lower voltages) wired between battery and lipo pack. I also have a blade fuse holder wired up with a 25amp fuse.
The Bix power battery comes with integrated on/off switch.

 

[pullin-gs]

Range update....got 29.5 miles today on mostly level paved bike path....kept it around 11mph maximum under power...never pedaled.
That is not too shabby for a 36v 8AH pack.
Range is 14 miles when I'm full throttle (20Mph average) until LVC of controller.
I am working on a quick-change setup for rear wheel so when I decide to go for long unpowered ride I can use faster wheel.
I loose 1.5MPH when usnig hub-motor wheel unpowered compared to fast wheel (no hub motor, narrow high-pressure tire/wheel, 28x 14G stainless spokes).

 

[Chalo]

****4/20 Update***
Joined the 500 mile club yesterday!
Got weight down to 49lbs....

How? Terra Trike lists the weight for your model as a range between 39.5 and 43 pounds depending on options. That's without motor, controller, wiring harness, switchgear/controls, or battery.

The Q128 isn't a heavy motor, but I have a very hard time imagining that you could add it, plus all the other things I listed, within a net weight budget of at most 9.5 pounds.

 

[pullin-gs]

Sorry I did not itemize weight before.....here are the specs:
Base weight: 37lbs (mine has 20" wheels and standard 24sp gears....rear-internal geared hub model is much heavier...26" model has pretty steep weight-tax also)
https://www.utahtrikes.com/UT2-WWSPECS.html

Ditch all the reflectors, lights, seat bag, etc.: -1 lbs.
Replaced boat-anchor stock 11/30 cassette with much lighter 11/32 (gave me slower gear to make up for removal of small front ring)....remove front shifter&cable, steel derailure (sp?) & mount...swap out locking break lever...replace rear twist shifter w/thumb shifter and updated cables.: -1 lbs
Upgrade crankset to single speed unit...hollow aluminum...aluminum clipless....crank-side upgrades knocked off over 2lbs!: -2.5lbs
Trike weight: about 32.5lbs.
.....
Motor weighs in at 6.5 pounds (before I cut most of cable off).
https://bmsbattery.com/ebike-kit/768-16765-q128c-135mm-500w-rear-driving-ebike-hub-motor-ebike-kit.html#/43-voltage-48v/214-rpm-328
Controller (removed heavy finned aluminum enclosure....did'nt need it in that it is rated 38 amps and I only do half that max). 1/2 pound.
Battery: 5.5 lbs
https://www.bixpower.com/BAT-BX3691B-p/bat-bx3691b.htm
Full weight when accounting for obvious items: 45lbs
Misc stuff that impacts weight (heavier rear wheel rim, spokes, tire, wiring harness): ~4lbs
That pretty much covers it.
TOTAL: 49lbs.....on paper AND measured.

PS: I usually run my 8AH homemade LIPO! I found it has much less voltage dip....is 2MPH faster than 11AH panasonic pack....weight goes up 5 pounds though. :-( ...but worth every ounce! :-D