36V 250W controller replacement

[clockwork247]

Hi Everyone,

I managed to get an ebike off CL, but it has a bad controller (I tested it with another controller from my other ebike and it works).

So I need a new controller, unfortunately everything is in Chinese, and I can't figure out what I need.

I know that it's 250W and 36V. But 250W controller are so hard to find on ebay, they are all 350W plus.

I attached some pictures, can someone point me to the right one? Thank you.

 

[motomech]

There is no "right one".
Look thru the many on Ebay for the Rating (in Watts), the size and the features you need.
What ever you buy, the colors of the power wires (power-main, phase and Halls probably will match), the others, maybe, maybe not. There is no real standards and basicly what you will need to do is ID the controller functions to a group of wires and match those to the bike.
The connectors are an even worse situation, they almost never match and the best thing to do is to change them to new matched ones, like 6 M/M bullets, JST's and the like.
The 350 Watt rating is not a problem.

 

[clockwork247]

There is no "right one".
Look thru the many on Ebay for the Rating (in Watts), the size and the features you need.
What ever you buy, the colors of the power wires (power-main, phase and Halls probably will match), the others, maybe, maybe not. There is no real standards and basicly what you will need to do is ID the controller functions to a group of wires and match those to the bike.
The connectors are an even worse situation, they almost never match and the best thing to do is to change them to new matched ones, like 6 M/M bullets, JST's and the like.
The 350 Watt rating is not a problem.

I have a question about wiring, There are a set of wire I'm just stumped:

The plug that's marked "K". This is a wire that came from the on/off switch at the handle bar. originally it's a Yellow and a Green wire, when they get down to the controller they split the wire up. the green is wire into the plug, and the yellow is connected to the black wire.

This black wire comes from a set of 3 wire (red/yellow and black), all 3 are solder/bolted to a piece of metal plate, effectively I would call all these 3 wire "ground".

the remaining set of the wire (yellow and red) are going into a plug (bottom right of picture), into the controller.

My question is, the switch is just 2 wire, why did they split it up? and why do they need the 2 "ground" wire into the controller? wouldn't 1 be sufficient?

I measured the green/yellow wire, it measured 5V.

for the replacement controller, the switch is actually 2 wires going into the controller... do I split the wire like the original setup? or do I go positive/negative into the controller?



My electrical skill isn't that great, stuff like this isn't my forte at all . Thank you in advance for the help.

 

[motomech]

Ok, those are an unusual bunch of colors. If it's a "factory built" bike, that probably isn't suprising. Perhaps that makes it difficult to follow the wires and see what they go to.
You could do more research by looking at the wiring codes that most controllers have on their "vendor" page to see if you see one that matches. But I doubt you will.
What I would do is get one or two new controllers (they are cheap and a spare is always good), ID the wires needed to make it run (Which I will do below) and go from there.
But first, you need to think of what features does the bike have and how bad do you want to keep them. Does it have a display, what type? Does it have PAS? Does it have a speed-limiting switch, how many speeds? On/Off switch?
In general, we know;
1)Big red and blk - power
2)all reds - positive ( switched only by the main switch)
3) all blk.s and gr.s - Neg.
4) Blu - often a "trigger" to turn the system on.
5)Big red, blk, Yel, Blu and Gr - phase
6)Tiny of the same set - Halls
7)Sm. red/ Gr/ Blk - throttle (These may vary by one color)
Unless there is bundle that goes to a display, that's usually what it takes to make the bike run.
PAS wires look like throttle wires and both will have 5 Volts across the Pos./Neg. w/ the remaining wire the "signal" (varies 1 to 4 Volts depending on device position)

The good news is, beside crossing the Pos and Neg. wires (especially the big ones), you can't hurt the controller by connecting the other wires incorrectly. It just won't work.

In answer to your question those wires you mentioned are probably for the Brk. cut-off circuit and split to facilitate going to both brk levers. Or they are for something called EABS, which nobody here has ever figured out what that is.
When trying things out, leave grouped wires that you are unsure of dis-connected and they are out of the loop.
I always get my controllers from this out-fit;
https://www.ebay.com/str/diyebikestore/Controller/_i.html?_storecat=3549975010
I don't know if they are any better than the others (if they work, they are pretty much all the same), but I do know some of what's sold is junk.
This ebay store is actually PWS Power, a big vendor out of Singapore and they are prompt and their products are good.
When trying everything out, you can use wire-nuts for temp. connections and we can go over more perm. ones if you get that far.
I would get the 350W over the 250W, although it will pull a littler more from your batt., it will add a little more "torque".
If your batt is original and more than a year old, it could be that when you get everything working, it will start dying.
That's the way ebikes work (or don't.