Technically, Do I even need a controller?

[Nashville Kat]

If for simplicity and weight's sake I wanted to just put a button between my battery and hub motor, would that work? Can I just pedal up several miles an hour and push a button to turn on power and take my finger off when I want it off?

technically speaking that is. The battery seems to indicate it's level at the push of a button right on it- I don't think I'm interested in any pedal assist for the small use trips of several miles I may need in my mid-60's. I know the brake cut-off is generally a good idea, but I'm talking about having my hand on a button and not turning on a switch .

The twist grips and thumb controllers seem to have three wires- if I wired one of those- does power go to two wires, or is that where the controller comes in? If I pedal up to speed can I just be on/off then?

Thanks in advance!

Great rolling and lightweight 26 x 1.1 tire Geax Lazcem

 

[Nashville Kat]

So anyway- after losing some text earlier-

Here are my three controllers- The big black one came with my eBike 36v 500 watt 700c wheel

and I thought the weight excessive at .0.95 lbs. On a roughly 25 pound bike another 1 pound for the controller alone is then about 4 percent more, before hub and battery weight added- too heavy.
So I got the middle sized one on ebay- and cheap then- I think about $10 almost a year ago.. Almost half the size and weight at .0.47 lbs

The third small silver one is half the size and weight again- 0.27 lbs for a 36v 250 watt hub wheel I got later. There are some connector problems to be adjusted with the lighter controllers and no pedal assist, yet more simple. I'm not sure how they'll function.

Nothing is up and running yet but will be soon I hope.

 

[Nashville Kat]

OK, I'm finding answers to my own questions- The answer basically- in my case/s is "NO"

Why? Because, as I discovered last night when I'd hoped to do a simple test to see if my 36v/ 250 watt 700 C wheel would respond to 24 volts of two car batteries wired in series- my motor wheels are BRUSHLESS motors and have Hall and Phase wire connectors.-

I found that the tiny 9 pin connector on the wheel made it almost impossible to even get alligator leads onto- even after I got the diagram online .

Things were sparking and smoking! At one point I welded the ends of the alligator clips to each other!

At one point the wheel spun forward- I don't think I ever got enough juice into the motor to even blow it otherwise-hoping at least

I thought the9 pin connector absurd anyway and with nothing to match it , thought I only needed to find the TWO Blue and Yellow wires to the motor labeled on the other controllers.

Anyway, I read up on it some more- after cutting the tiny 9 pin connector off and finding the TINIEST of wires between it and the hub -found out it was brushless and needs other connecting wires to keep the motor in phase and from sputtering-

I looked more carefully at the original controller- the heavy black one- for my original 500 watt kit and found the connectors for the same components on that one apparently also brushless, with THREE PHASE wires connected and a five pin HALL connector- and now pretty much locking me into using that one with the first kit - which is how I decided to build it at first anyway so that I could see if it was working with all the normal parameters in place- (I'll still leave off pedal assist if I can)

I then thought maybe my second 250 watt investment gone, thinking I'd never find the right stuff to hook up all those wires to- my newer controllers- including the one rated for 250 watts- did NOT have anything going to the wheel but two wires yellow and blue.

But I found now controllers on ebay for brushes motors- with the three PHASE wires (adding a thick green to the yellow and blue ones) and the five pin Hall sensors- (This wheel seems to have only three- so there may be some confusion ahead here) and not too expensive at $10-15. Wish I hadn't cut the five pin cause I can get a line for that with the same skinny things to run to the controller- and I'llbe struggling to connect those with blades or bullet connectors-

This was maybe going to be a beach bike I hope to power up with 24 v if it will and 10 or 15 is plenty of speed-

Anyway- the second wheel is on the back burners, and I'll be proceeding with my 36v 500 watt 700C front kit on a lightweight GT step through frame with upright alloy bars- A CITY Transport bike- and the Lion battery on the back rack with folding saddlebags and a front basket as needed- 700C rims with 28mm tires. In no hurry, but hope to have it going in a month or two-

Only had the kit for almost a year!

 

[scratchbuilder]

Can you tell me what the 'learning plug does? I too have a hub motor ( brushless) and you answered my question of testing the motor directly to the 48v power source...dont! Lol. I have a 'baja 500be scooter 2008, sat for 6 years..traded labor for it, and I'm trying to find a way to get more than 15mph out of it. Have you heard of governors on hub motors.?

 

[cannonball2]

Running with out a controller is like driving a car with the throttle wide open all the time and controlling it with an ignition kill switch. Not a great idea.

You can with in reason run any brushless motor on any voltage. But it's easier to use a controller of the voltage you want to set the battery cut voltage correctly for the battery. I have run the same 36 motor on 33v and 63v using a 24v controller. I just had to be careful to monitor the voltage and cut operation at the proper voltage. The 24v controllers LVC would have killed the the higher voltage packs.

Scratch, there is a set of wires that when connected limit speed to 20mph to be legal in some regions.. unless there is a handlebar switch with a control box, I use only the necessary wires such as throttle, phase, hall sensors, battery input. Rarely do I bother with brakes.
Most cheap controllers have 63v caps. I have been running one cheap 48v controller on 63v for years.
You can do pretty much what you want once you understand the systems.

 

[Otero]

Some years back I built a DIY ebike with absolute no idea what I was doing. I used
the heater fan motor off an old school bus & the rheostat from a 50's radio with
2-12v motorcycle lead acid batteries during the Jurassic era. Apart from being
terrifyingly unwieldy, It got down the road pretty damn fast for about 2 miles
before bursting into flames.

 

[kevyleven007]

Well, now you know. I've wrecked several battery packs and kits finding out what not to do, 8-9 years ago

 

[Nashville Kat]

DAMN! This friggin bike is seriously FAST. I got it out on the road finally late tonight. My first thought was- "This is as fast as my 50 China Girl" And totally quiet. I'm impressed and ready to fine tune this rig. I'll post some piuctures of it soon- a GT step through with 500 watt 36v front hub motor. 700C alloy wheels with 28 mm wide tires. The bike feels light compared to my 45 lb Huffy 50cc .The battery is large wormed clamped to the back rack with the controller held on with the same clamps on top. It was night, and may have seemed fast, but I must've been doing over 20 out there- and judging from the analogue speedo on one of my china builds- Wish I had done this set-up about five years back, but I don't think the lithium batteries were around much then. anyway, impressive- Too old for this really- I have a 250 watt motor that may be more what I should be looking for- 15-ish.

 

[Otero]

It's been years since the dubious heater motor fiasco. ^ I finally opted for
a purpose- built electric after waiting for technology to catch up with the capabilities
of my gas bike. I got a Juiced Bikes CCS, 650 watts, up to 30+ mph. I love it; it's
an elegant commuter, but my gas bike still has more range, power,& is an ATV.

 

[Dan]

Some years back I built a DIY ebike with absolute no idea what I was doing. I used
the heater fan motor off an old school bus & the rheostat from a 50's radio with
2-12v motorcycle lead acid batteries during the Jurassic era. Apart from being
terrifyingly unwieldy, It got down the road pretty damn fast for about 2 miles
before bursting into flames.

LoL, O!

 

[Nashville Kat]

Here's the finished product. I did a six mile or more round trip this weekend and on return three of the four battery power indicators were still lit up- so it looks like it'll have a range for my urban transport purposes. This thing is really quite fun-

 

[bluegoatwoods]

Nice job there, Nashville Kat. A sleek and competent looking e-bike.

 

[Dan]

Hey (kewl) Kat. Any updates?

 

[Nashville Kat]

I posted this thread in "pictures"
https://motorbicycling.com/threads/gt-electric-500watt-step-through.63901/

and as for the original question about a controller, I think with a simpler non-hub motor- probably not. Here's what one guy did with 12 volts and a small $10 motor

It's been a slow summer with lots to do, and I haven't had a lot of energy for much riding. I did change the alloy sprocket to a classic vintage SR campy clone with 42 teeth for greater pedal assist at higher speed. This 39 Stronglight 93 has been assigned to the vintage '60's Peugeot I'm building for the 700c 36v 250 watt hub I also got a correct controller for.

The bike is almost built and I'll take some pictures- I have to fashion a harness of my own, and still haven't a battery, but here is the frame before and during painting. I'll probably use the mixte top railing to clamp the battery to instead of a rack, and use only a front basket. It matches the decals somewhat of the 1967 Peugeot PX10 I've had since '87.

https://www.facebook.com/photo.php?fbid=1988418921184806&set=pob.100000501511271&type=3&theater