New guy from WV. Need help with a battery and probably more. (NOW RIDING)

[pnop]

New guy here. I have some questions. I own an electric car so should be able to figure it out on my own but I'd rather get it right.

I bought this bike at an auction. There is no battery. Maybe original owner didn't know what to buy either as the bike appears new. Picture below is the wiring and the motor. 36v 750W. I'm assuming the mess of wires are largely not needed? What battery would work here? I'm not looking for real fast speeds or long miles. It would just be used to run around town.

Thanks

 

[harryS]

Some of the wires in your "mess" won't be needed, but don't cut anything you figure out what is what. Here's my opinion.

1) The cable on the right side of the photo with the three ring connectors goes to the motor. There are three wires in the middle with similar ring connectors that must be joined. Match color to color. The rectangular white connector (already connected) that also goes to the motor cable contains the sensor wires from the motor.

2) The two pairs of red/blue should go to your two brake levers. Already connected.

3) I believe the six wire black connector just above your unconnected rings is for the main control, Does it include a throttle unit or is it just a display with a start button?

4) Is the 4 wire plug (yellow, red, black, white) connected? If so, where does it go?

5) The unconnected 3 wire (red, black, green) connector could be throttle, pedal sensor, or a wheel speed sensor. Depends on if you find these entities on this bike. Look around the crank for a pedal sensor. Speed sensors will be on wheel frame, with corresponding magnet on spokes.

6) The remaining single connectors are usually jumpers for speed limiter, cruise. The two wire red/black is likely for lights.

You probably already figured out the red/black bullet connectors are 36V power. This is a front drive 750W bike? If so, are the front forks steel? That kind of power can tear out up any alloy fork and probably rip a steel one too, depending on how it was made. I'd be very cautious. Don't put a 1000W controller inside a bag. It will get too hot.

RIg up 36V for testing. If your throttle is connected, should work. Motor will pull 26A. Be careful. Have fun. Don't put a

 

[pnop]

THANKS, that was a lot of help. I'll have to check on the wires in question when I get home tonight.

Yeah, 750 seemed overkill on a front wheel bike to me also but I do not plan on running it hard.

Any suggestions on a battery? I've read where many of the 36v batteries say they are not recommended for 750.

Are they generally standard as far as plugs go?

Thanks again.

 

[harryS]

A 26A controller should probably have a battery capable of sustaining 30A. You can always use a small battery to see if the power powers up and spins the wheel with it off the ground. When you try pulling max currents thru a battery, it can wear down the cells and even damage them. What kind of bike is this that uses a 750 hub on a 20" wheel?

Batteries are often specified in AH, but should also have the max current listed. If not then you probably shpuld avoid it.

 

[pnop]

OK. three wires connected. What kind of battery are we taking about to test it?

 

[harryS]

You can test the motor off a 40V (actually 36V) weedwhacker battery, if you have one. A kid's 36V4AH hoverboard battery.

 

[pnop]

You can test the motor off a 40V (actually 36V) weedwhacker battery, if you have one. A kid's 36V4AH hoverboard battery.

Great. I have a 40 volt Lawn Mower.

 

[Ann M.]

pnop, it would be a good idea to add a Torque Arm on that front hub motor so it doesn't twist inside the front dropouts, especially at a start or quick acceleration. Grin Technologies offers several styles and the are the best out there. The torque arm anchors the motor axle; it's no fun if the motor axle rotates in the dropouts and rips your motor wires.

 

[pnop]

No, that doesn't sound good. The forks are steel but I think I could make something like that. I have a plasma cutter and steel laying around.

Thanks

 

[Big Tom]

IMHO that hub is a 500W with a max of 750. From the picture it looks like one of the Chinese kits

 

[rich c]

I'm assuming the mess of wires are largely not needed? Never worked with a bike controller, but yet you assume most of the wires do nothing. That's a hoot!

 

[pnop]

I'm assuming the mess of wires are largely not needed? Never worked with a bike controller, but yet you assume most of the wires do nothing. That's a hoot!

Thanks for the helpful reply. So what do they do? (And I did NOT say, do nothing. I said not needed). Why do I need them?

 

[pnop]

IMHO that hub is a 500W with a max of 750. From the picture it looks like one of the Chinese kits

Thanks........think I would be OK with a battery for a 500W? This is not a long ride bike or going to be rode full out.

 

[J.R.]

Thanks for the helpful reply. So what do they do? (And I did NOT say, do nothing. I said not needed). Why do I need them?

Generic Chinese controllers often come with connections for lights, brake lights, blinkers, etc... They might also have cadence sensor and regen connections. Hard to say. The same controller could be used for electric scooters (vespa style), e-kick-scooter and traditional ebikes. It's likely you don't need them all.

Good luck! Post a pic when you complete your project.

 

[Big Tom]

Thanks........think I would be OK with a battery for a 500W? This is not a long ride bike or going to be rode full out.

Yes, IMHO a battery for a 500W will work . The motor is limited to how fast it can go depending on how much power it can draw. All of the 500W kits I've had needed a 15 amp bms board so make sure the battery specs have that.
Where in WVA do you live? I'm in Columbia MD and have a battery you could borrow/buy that will work. Happy to meet if you are close.

Harry S posted the correct wiring hookups. Don't worry about all of the extra wires. You will need a display, did the bike have one? It would have the on/off control on it. That plus into the black connector with (I think) 5 wires. The wire colors should match. The throttle is the three wire Harry mentioned however the wire colors will NOT match but not important if the connectors are the same.

 

[pnop]

I'm in the Parkersburg area. Unfortunately appx 5 hours. The bike does have a thumb throttle with a three light display and on/off switch. I'll get more pictures in a bit.

I do like the battery technology. I have an electric/hybrid. My lawn mower is electric. Weed eater, drills, saws etc all electric. I've seen ONE electric bike. There are only 1-2 bike shops in the area. None with electric bikes. I got this bike cheap as a way to get my feet wet.

 

[Big Tom]

I'm in the Parkersburg area. Unfortunately appx 5 hours. The bike does have a thumb throttle with a three light display and on/off switch. I'll get more pictures in a bit.

I do like the battery technology. I have an electric/hybrid. My lawn mower is electric. Weed eater, drills, saws etc all electric. I've seen ONE electric bike. There are only 1-2 bike shops in the area. None with electric bikes. I got this bike cheap as a way to get my feet wet.

You can get the power hubs in a kit pretty cheap these day, put it on any bike you like. That way you don't need a specialty bike shop.

Yours is a front wheel hub. It will pull instead of push you and will feel funny at first. I use the rear hubs so the feel is the same however the installation takes longer.

Is it really a 20" wheel?

 

[pnop]

Yes, it is really a 20" wheel. It's on a folding bike. I will probably upgrade at some point but if this works, I will keep it around. I understand the short comings of a front wheel drive bike. Most certainly have to be aware of surface.

Not to be ignorant but I am......Power hubs? As in?

Thanks.

 

[Big Tom]

Yes, it is really a 20" wheel. It's on a folding bike. I will probably upgrade at some point but if this works, I will keep it around. I understand the short comings of a front wheel drive bike. Most certainly have to be aware of surface.

Not to be ignorant but I am......Power hubs? As in?

Thanks.

What you have is a Power Hub that powers the wheel, as compared to a mid drive that powers the crank. Hub turns the wheel at a certain speed regardless of gear. Mid drives will turn the crank like you are pedaling so the gear you are in affects the speed of the wheel. I like the power hubs due to their simplicity and ease of installation. In power hubs there are two types, geared and direct drive. Geared gives you much more torque and IMHO is a better hill climber then a direct drive.

 

[pnop]

OK....two pics and questions. I decided I would dump the bag. While I do have quite a bit of electric things, I'm obviously not an electrical engineer. LOL I do understand the relationship to heat and this stuff.

Anyway, I took my 40 volt battery and put two spade connectors in it. Took a jumper to the red black. (yes I do know black is ground, etc.). I just want to make sure........I don't want to mess up my battery. When I went to hook the positive, I got a nice big snap. I suppose I've only messed with 12 volt before. You get a snap but I know what I'm doing is right. I guess 36 volt is going to be more pronounced?

Battery still working in mower. Just ignore the snap or do I have something wrong? (In the picture I do not have the red/blue from the harness connected. I'm guessing that is the brake disconnects).