A friends Bike

[mcsg]

Hey! Hoping for some direction please as this bike doesn't go.
I have take on a job for a friend. She has had this bike in storage and I've just charged the battery, charge is at 52V, the gauge says it's at Empty. The key turns on and permits 52 volts to controller. I've checked plugs and wiring and it all looks good and clean. There doesn't seem to be a fuse that I can see. The motor magnets and hall effect switches work so I imagine the motor is fine. The pedal assist plate seems to be missing, although the sensor is still there, the lights all work, brake switches work, the throttle feels fine, it has 3 speeds, I think it has an alarm perhaps. What information is required that would help me work this out. 5 volts at the throttle plug, 5 volts at the pedal assist plug, 5v to the motor wires.

 

[mcsg]

 

[glennb]

You sure you want to undertake this? Considered offloading it for whatever you can get and investing in a ninebot?

What you have is a scooter, because it can't be pedalled. That's fine, I love scooters as much as the next person, however with this design you're burdened with a heap of unnecessary weight and complexity. Heavy, wobbly, squeaky, creaky, and embarrassingly ugly. There's no positive adjectives to describe it unfortunately.

Scooter's needn't be small wheeled. Have a look at kick bikes. They're great fun, very efficient, and look a treat. Front wheel motor kit and away you go.

Or else just a front motor kit on a pretty ladies bike if pedalling's more her thing.

 

[mcsg]

You sure you want to undertake this? Considered offloading it for whatever you can get and investing in a ninebot?

What you have is a scooter, because it can't be pedalled. That's fine, I love scooters as much as the next person, however with this design you're burdened with a heap of unnecessary weight and complexity. Heavy, wobbly, squeaky, creaky, and embarrassingly ugly. There's no positive adjectives to describe it unfortunately.

Scooter's needn't be small wheeled. Have a look at kick bikes. They're great fun, very efficient, and look a treat. Front wheel motor kit and away you go.

Or else just a front motor kit on a pretty ladies bike if pedalling's more her thing.

Thanks for your advice. I'd like to fix this ugly duckling not look at it.

 

[RunForTheHills]

Are you sure the battery is still good if it's been stored for a long time without maintenance charges? A fully charged 48V battery will be at 54.4V and a fully charged 52V battery will be at 58.8V. A bad battery may show a good charge, but will have voltage sag under load.

 

[E-HP]

Pics of the display and display connector might be helpful. I would start by disconnecting all of the connectors except the battery, motor, and throttle; and display if needed to turn on the controller.

 

[offGridDownUnder]

as this bike doesn't go

Perhaps more description of the behaviour.

Does the motor turn? Describe what you do to make this happen.

Any odd noises? Any odd feelings when you turn the motor by hand?

brake switches work

Electrically? Or do you mean they move and you feel a click, but you have not checked them electrically?

Those sorts of details, please.

Despite no power, can you ride it? That is, do the cranks turn, no clunks, no funny noises, does it shift? I expect it might not be fun, but it's information about the mechanical platform underlying the motor function, and that can quickly eliminate guesses we might make.

the gauge says it's at Empty

Gauge on the battery? Or a gauge on a display? Is there a display? What does it show?

 

[docw009]

Trace the wires from the brake switches and make sure the levers are not open, activating the switch, and inhibiting the motor. You can also unplug the brake cables to be sure they aren't shutting you off.

Check the signal wire on the throttle. It should sit at .7V and rise up to around 4.3V as throttle moves.

You appear to have black and green wires dangling unconnected in that bottom picture. Doesn't bother you? ALso a two pin connector dangling in one if the other photos,

Is there a display for the bike? If so, what does it do on power up. Could be you have an alarm immobilizing the bike,

 

[mcsg]

A quick update. I noticed that with the key in the off position only the white wire going to the throttle 52.2v. Key on, White wire 52.2v, yellow wire 52.2v, red wire 5v, black 0 and green 35.2v( not too sure how this voltage is coming down the green wire. The green wire has no change in voltage when the throttle is operated either. It should raise the voltage as the throttle is increased?

 

[mcsg]

Perhaps more description of the behaviour.

Does the motor turn? Describe what you do to make this happen.

Any odd noises? Any odd feelings when you turn the motor by hand?



Electrically? Or do you mean they move and you feel a click, but you have not checked them electrically?

Those sorts of details, please.

Despite no power, can you ride it? That is, do the cranks turn, no clunks, no funny noises, does it shift? I expect it might not be fun, but it's information about the mechanical platform underlying the motor function, and that can quickly eliminate guesses we might make.



Gauge on the battery? Or a gauge on a display? Is there a display? What does it show?

All good questions, thank you for replying.
Motor will turn by hand only. no odd noises. No odd feelings when the wheel is turned.
This is a very small bike but I can ride it, no problems or noises, only has one gear with a 3 speed switch, which obviously doesn't do anything at the moment.

Battery has 52.2v, gauge on the display/led illuminates only the 'E' light. A bit strange.

 

[mcsg]

Trace the wires from the brake switches and make sure the levers are not open, activating the switch, and inhibiting the motor. You can also unplug the brake cables to be sure they aren't shutting you off.

Check the signal wire on the throttle. It should sit at .7V and rise up to around 4.3V as throttle moves.

You appear to have black and green wires dangling unconnected in that bottom picture. Doesn't bother you? ALso a two pin connector dangling in one if the other photos,

Is there a display for the bike? If so, what does it do on power up. Could be you have an alarm immobilizing the bike,

Thanks for your suggestions.
I checked the brake switches yesterday and also disconnected them to take them out of the picture but made no difference, same with the PAS as the plate on the cranks is missing.
Yes, I know the throttle signal wire should read under 1v and rise as the throttle is twisted. Given my lack of experience with these ebikes I wasn't sure if this was the case with all ebikes. But doing my research I am finding that there are some standard readings across the board for most ebikes, which is nice.
Yes, the green and black wires have been cut prior to me looking into this issue, there is a speaker type box that has wires going to it, hence my thinking about an alarm possibly. The two pin connector has no other connector to connect with, I can't really do anything with that.

 

[mcsg]

 

[mcsg]

Are you sure the battery is still good if it's been stored for a long time without maintenance charges? A fully charged 48V battery will be at 54.4V and a fully charged 52V battery will be at 58.8V. A bad battery may show a good charge, but will have voltage sag under load.

I thought this too. It's a 48v system, so I figured at 52v there would be something happening, even on the bench under no load rather than riding the bike.

 

[mcsg]

Pics of the display and display connector might be helpful. I would start by disconnecting all of the connectors except the battery, motor, and throttle; and display if needed to turn on the controller.

Thanks for your reply. Have done that, no difference. Due to the fact that I have no spares, I can't try anything or swap anything out, so I was wondering is there a way to bypass the potential restriction or problem to get it working? I know this all seems a bit pointless but it's good experience for me as this is only the 2nd ebike I've worked on with problems, so I'm learning all this in one day basically. I'm jotting the information into a database that I can use later for my side hustle bike repairs business.

 

[offGridDownUnder]

Yes, the green and black wires have been cut prior to me looking into this issue, there is a speaker type box that has wires going to it, hence my thinking about an alarm possibly

Did someone cut the wires to the alarm speaker because they could not stop the alarm sounding?

 

[ak136]

Battery at 52V but gauge says empty

I had couple of KT controllers that would behave the same, turns out communication between display and the controller is bad (cable was good)

Manufacturer told me to replace the controller

 

[mcsg]

Did someone cut the wires to the alarm speaker because they could not stop the alarm sounding?

Good point.
I'll ask the question.

 

[mcsg]

Battery at 52V but gauge says empty

I had couple of KT controllers that would behave the same, turns out communication between display and the controller is bad (cable was good)

Manufacturer told me to replace the controller

Fair enough.
I guess i'll check continuity from controller to display, but I know the wires are good because the leds are on and the key turns power to controller on and off.

I think the 35.2v from the throttle to the controller is a problem and the controller won't let anything happen till that's sorted. I'm thinking the throttle with the display attached is faulty. I can't really check that though can I? Is there a work around?

 

[docw009]

A quick update. I noticed that with the key in the off position only the white wire going to the throttle 52.2v. Key on, White wire 52.2v, yellow wire 52.2v, red wire 5v, black 0 and green 35.2v( not too sure how this voltage is coming down the green wire. The green wire has no change in voltage when the throttle is operated either. It should raise the voltage as the throttle is increased?

So the throttle has presumably these 5 wires? I assume the fifth wire is black,. WIth Key ON,
52V White always has power
52V Yellow
35V Green
5V Red
Black, is the ground wire.

Here's how a 5 wire throttle should work. Key is off, Only one wire (white) has power. Key turns on and switches 52V to the yellow wire. When the yellow wire sees 52V, the controller turns on and returns 5 volt on the red wire, The Green wire should be low voltage from the throttle,

I would unplug the throttle and verify with a continuity tester. White and yellow are being connected when the switch is on. Then plug the throttle back in, but leave the red and green wires off. See if they read 5V and 0V respectively, You want to know if the 35V comes from controller or the throttle,

By the way, your 52.3 volt reading could just be a miscalibrated voltmeter, Check the output of the charger. If it is the same (53V), then it's just meter inaccuracy, If the charger shows 54,6V, well, it;s an older battery, They don't always reach full charge. The throttle really should show all four orange LED's here,

 

[fechter]

Since the display is showing the battery is empty, it may be preventing the motor from running.
There is probably a separate connector for the throttle on the controller. You might try measuring the voltages at that point. You could trace the wires back and see if it goes to the throttle. If the green wire is supposed to be the throttle signal, 35v would definitely be wrong.

 

[mcsg]

Since the display is showing the battery is empty, it may be preventing the motor from running.
There is probably a separate connector for the throttle on the controller. You might try measuring the voltages at that point. You could trace the wires back and see if it goes to the throttle. If the green wire is supposed to be the throttle signal, 35v would definitely be wrong.

Yes, display showing E could prevent motor from running is a possibility, throttle and display are the same connector, 5 wires. Green wire voltage is definitely too high. Problem is where is it getting that 35v, controller or throttle. I guess I'll have to cut the wires from the connector to find out.

 

[mcsg]

Removed green wire from 5 pin connector and key on 51.5v coming from controller.

Probe in the green wire spot with green wire removed from connector, key on, nothing coming from controller.

Key on Red wire 5V

Yellow wire 52.2v

So I think a throttle/display is needed to make this thing go.
Next question could be, do I just buy something like this controller and throttle?

https://www.aliexpress.com/p/tesla-landing/index.html?scenario=c_ppc_item_bridge&productId=1005005211363400&_immersiveMode=true&withMainCard=true&src=google&aff_platform=true&isdl=y&src=google&albch=shopping&acnt=231-612-1468&isdl=y&slnk=&plac=&mtctp=&albbt=Google_7_shopping&aff_platform=google&aff_short_key=_oFgTQeV&gclsrc=aw.ds&&albagn=888888&&ds_e_adid=&ds_e_matchtype=&ds_e_device=c&ds_e_network=x&ds_e_product_group_id=&ds_e_product_id=en1005005211363400&ds_e_product_merchant_id=109207496&ds_e_product_country=AU&ds_e_product_language=en&ds_e_product_channel=online&ds_e_product_store_id=&ds_url_v=2&albcp=22977950089&albag=&isSmbAutoCall=false&needSmbHouyi=false&gad_source=1&gad_campaignid=22967632716&gbraid=0AAAABBR8kP06qwZmwkZtzgSmUhOvy89d3&gclid=Cj0KCQiAqeDMBhDcARIsAJEbU9SCw4vAQgzVKpKfGxk26hVbRVSm1TOyrgeAM5beI4A2gCRTG0MdpM0aAj-REALw_wcB

Or do I just get a display throttle like this throttle on it's own?

https://www.aliexpress.com/item/4000070008863.html?spm=a2g0o.tesla.0.0.49869LpW9LpWDk&pdp_npi=6%40dis%21AUD%21AU%2432.61%21AU%2427.39%21%21%21%21%21%402101f54117716411350631240eb32a%2110000013390566280%21btfpre%21%21%21%211%210%21&afTraceInfo=4000070008863__pc__c_ppc_item_bridge_pc_related_wf__3pcVLmM__1771641135447

 

[mcsg]

sorry, that first pic is green wire coming from throttle not controller.

 

[mcsg]

I pulled a part the throttle looking for reasons why the 35.2 volt on the green wire. I see here that the red wire is kinda connected but not, it's just sitting there at the hall effect sensor, when I actually give it a proper connection I get 17.3v. Essentially half the voltage being returned previously via the green wire.

 

[mcsg]

Either way, it's no good, the wheel will not turn. I'd say now that the hall effect switch/sensor is U/S. Red and green connected to the hall effect 17.3v each, red disconnected from hall effect goes back to 5v from controller and green goes back to 35.2v. So the issue is in the throttle, confirmed.