Ebike yose power failure

Naycrx

Pedelecer
Feb 11, 2020
26
1
Good afternoon,

I have a 36v 350w yose power rear hub drive with a built in controller with the battery holder.

A few weeks ago the power kept turning its self off. I contacted yose they sent me a new battery under warranty. I have since managed to do 3 rides on it now problem around 75 miles. But my last ride again the power started to switch off I seem to be able to ride approximately 1/2 a mile before all power is lost. I now can't Evan switch it back on.

Any ideas!????
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,993
Basildon
Try the simple things first. Have a look at your motor connector and make sure that it's all the way in to the line and not just in rtight. After that, you'll need a meter to check the battery and charger voltages. Check your battery immediately after charging, then again when it cuts out. that should give a good clue as to where to look for the cause of your problem.

Another thing that happened to some people with that kit was that they accidentally set it to 48v in the LCD instead of 36v, which will give the symptoms you have.
 

Neilneilorangepeel

Finding my (electric) wheels
Mar 16, 2020
20
0
Try the simple things first. Have a look at your motor connector and make sure that it's all the way in to the line and not just in rtight. After that, you'll need a meter to check the battery and charger voltages. Check your battery immediately after charging, then again when it cuts out. that should give a good clue as to where to look for the cause of your problem.

Another thing that happened to some people with that kit was that they accidentally set it to 48v in the LCD instead of 36v, which will give the symptoms you have.
I have the same problem, but can't check whether it's accidentally set to 48 volts as the power won't come on. The LCD display unit ... is that the controller, making decisions, cutting out for safety, etc, or is it just a display and the real CPU part is in the part that the battery attached too? The reason I ask is that if I can't find out what's wrong, would it be worth buying a replacement LCD unit? (The first thing that went wrong was the unit stopped displaying speed, then it kept shutting down, now won't start. This happened over a period of a few weeks. The battery and charger seem fine )
 

Neilneilorangepeel

Finding my (electric) wheels
Mar 16, 2020
20
0
Have just messed around with it a little more, used a hair dryer in case parts were damp (not on the battery, just the LCD display and battery attachment) and it did show signs of life. The LCD flashed up briefly, backlight on, but went off as soon as I released the power button. Maybe this will help someone with a diagnosis ....
 
Last edited:

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
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Basildon
When the LCD flashes on like that, it means that the battery is switched off - normally because of a fault in the battery.

First, measure the actual battery voltage at its terminals with a meter.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,993
Basildon
Put your meter in the connector between the battery and controller while you attempt to switch on the LCD and see what happens to the voltage. If it collapses, either you have a short in the controller (blown mosfet) or a faulty connection between the battery and the connector.
 

Neilneilorangepeel

Finding my (electric) wheels
Mar 16, 2020
20
0
Sorry if this is a dumb question ... when I connect the battery, the prongs of the controller disappear into the slots of the battery, so how can I connect a multimeter? There's nowhere to place the probes when the battery is connected ...
 

Neilneilorangepeel

Finding my (electric) wheels
Mar 16, 2020
20
0
Maybe I should say the controller is built into the battery housing, so there's no cable between then when the battery is connected.
 

Scorpio

Esteemed Pedelecer
Apr 13, 2020
372
164
Portugal Algarve (temporary)
Hi, It sounds like your Yose kit is similar to mine (everything is built-in so is difficult to test with a multimeter).

Does your battery have a push-button to check voltage, with a row of LEDs to show the charge? Maybe try that before and after it cuts out. The gauge is very basic but is still useful.
I think (can anybody confirm?) it's ok to power the bike on while it's being charged. Maybe put the bike on charge so you know the voltage is as high as possible, and while still connected to the charger try to power on. That might give you enough time to check the settings and make sure it's not been changed from 36v to 48v.
 

Neilneilorangepeel

Finding my (electric) wheels
Mar 16, 2020
20
0
Thanks, I will try that. The first fault was some garbled numbers on the display, for a few weeks. Then the speed showed zero for a few weeks, but everything worked normally. Then the power started cutting out, but could be switched back on immediately, again for a couple of weeks. Now fails to switch on.

For anyone else reading this, does this sound more like a failure of the controller, display unit, or battery?

For what it's worth, given my vast ignorance, I'm doubtful it's the battery as I charged it yesterday, it was on three lights, charged for a couple of hours, the charger light went green, and a multimeter test shows 41.5 volts, all of which suggests the battery is fine ...?
 

Neilneilorangepeel

Finding my (electric) wheels
Mar 16, 2020
20
0
Get some thin wires and strip back about 10mm each end. Put one end in the slot and slide in the battery. You can then test the voltage by probing the exposed ends of the wires.
Why didn't I think of that? Because I'm not as smart as you, clearly : ) Thanks a lot, I will try it
 

Neilneilorangepeel

Finding my (electric) wheels
Mar 16, 2020
20
0
Have tested the battery and it's fine. Have ordered a new controller from China. While waiting for it to arrive, is there anything obvious and simple I can do with the old controller to maybe get it going again. As it stopped after a night's rain, I've tried drying it out thoroughly, but to no avail...
 

StuartsProjects

Esteemed Pedelecer
May 9, 2021
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As it stopped after a night's rain, I've tried drying it out thoroughly, but to no avail...
I cannot directly think of a part in a controller that would be affected by water, especially if its been dried out quickly.

What does the controller PCB itself look like, if there are stains on the boards, that that maybe have the appearance of salt, then that could suggest a problem.

Got a picture ?
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,993
Basildon
It's normally the LCD that gets water in it. Before ordering the new controller, you should have tested running it with the LCD by-passed. I hope you ordered the LCD with your controller because there are two types of controller that look and fit the same, but they each have their own LCD, which are not compatible with the other controller. Plus, it's more likely that it's the LCD thats faulty.
 

StuartsProjects

Esteemed Pedelecer
May 9, 2021
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I would also suggest the LCD is a more likley cause of failure.

Most electronics is OK after it gets wet (for a short time) and is then dried.

One exception is electronics with membranes in them, think large keyboards for instance.

The water wicks into the membrane by capillary action and once in can be very difficult to dry out. Small pcb switches or LCD displays can use membranes so can be difficult to dry out.
 

MontyPAS

Esteemed Pedelecer
May 16, 2020
390
148

StuartsProjects

Esteemed Pedelecer
May 9, 2021
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Really ???
Yep, does depends on the purity of the water.

If in doubt rinse with plenty of de-ionsed water.

When I was looking after the build of BBC micros back in the 1980s, we started using de-ionised water to clean the PCBs in manufacture, following the requirements of the Montreal protocol.
 

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