One Wheel XR won't turn on
@Lia I wanted to ask you if the following method is worth trying to determine whether if it is the BMS, or controller. I stumbled upon someone suggesting this method in another thread:
"Another test to determine if it's the BMS or controller is to open the battery pack and unplug the BMS, connect the battery output directly into the controller. If the board turns on and balances then it's a BMS problem, if not then it's the controller."
Do you think this Is this worth trying?
@Vietrider802 I haven't tried the method myself however in theory there shouldn't be an issue. Was this test confirmed to work with your board version?
The battery box is easier to open so if you want to give that one a shot first that might be a good idea.
@Lia Honestly speaking, i'm not 100% but I think it's worth trying since the battery box is a lot easier to open like you said.
@Lia i’m suspecting it is the controller, so it could be the power button it self. I unplugged the BMS from the battery, and connected the battery output to the controller, and yet it didn’t turn on when i pressed on the power button.
@Vietrider802 Do you have a multimetre to test the voltage of the battery with just so we can cross that off the list?
Be careful not to short the probes across the contacts when checking. Safest method would be to unplug the battery from the BMS via the XT60 (yellow connector) and probe inside that.
Let me know the results and we'll move onto the controller if that seems fine.
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@Lia I realized I had made a mistake earlier. Went back and plugged the battery output into the controller, and it does turn on! The light is blinking telling me to “cycle charge”, or something like that? I could even turn the front and back lights on via the Onewheel app. When i placed my hand on the footpad, it shows that it senses my hand aka the feet icon moving up and down on the app. So now i’m suspecting its a faulty BMS perhaps?
@Vietrider802 That's a good start, implies the IC's on the controller are fine and the battery for the most part. Still brings into question what is causing the issue.
Do you have any pics of the BMS, get some HD close ups especially around that little connector with the black, blue, green and white wires?
PHOTO LINK: https://imgur.com/a/V0dpywz
Let me know if these photos are ok. I can take more if you need me to. Thanks!!
@Vietrider802 Looks pretty clean with no obvious signs of failure.
I have a test in mind to bypass the switch and toggle the BMS on but can’t say for certain what the pinout is so will do a test on my board first to verify it’ll do what I think.
The small white 5 wired connector speaks back to the controller. 2 black wires are going to be ground. Green and White together are usually Rx and Tx which would make sense since the controller and BMS talk to eachother. That leaves blue probably being the other pole for the switch. I need to verify this first so I’ll test my board first. There is a blue wire that comes out of the switching section of the power button so would add up if FM kept the colour coding uniform.
In theory with the BMS hooked up to the battery; shorting blue and black on the BMS side would do the same as the power button being pressed but please don’t try this till I’ve confirmed this should be the case.
If the test works we can assume the BMS is fine and the fault is controller side. If it fails it’s the BMS. I’ll get back to you when I’ve been able to poke around my board and figure out if this is a valid test with my wiring assumptions correct.
@Lia Will do! Thank you for looking into this. I'll wait until you confirm the results.
Lia last edited by Lia
@Vietrider802 I've tested my theory and it works the way I thought.
One correction for an earlier note I made, the 5 wires are green, white, black, blue, empty, purple. I thought the purple was another black wire as it's a really dark shade in my old pictures. The black; albeit ground appears to be isolated from the main ground so we can't use that.
If you re-assemble the battery (leave the metal lid off just in case) we can trigger the BMS to turn it on/off by shorting 2 pins on the large black and white connector that plugs into the controller. I've taken a pic with the relevant pins.
One corner has the blue wire connected, use my pic as a ref but check on the back of the connector if the blue wire on yours does indeed go into that specific pin. On the other end of the connector should be 2 red stacked atop of eachother and 2 black. The 63v circuit is presented on those and will not be present while the BMS is off.
If you take a short length of wire and strip the insulation off either end you can create a jumper wire. Place one end in the hole for blue (check you're putting it in the correct one first) and then connect the other side to either of the 2 blacks (again, check yours is correct). You only need to connect it briefly to turn it on so you can remove the wire after triggering it, now 63 volts should be present if you probe between the red and black pins.
Here is a video demonstrating what I did. I have a voltmeter wired into my board so was using that to demonstrate power output. www.youtube.com/watch?v=oB9El_sHD5I
You may need to use some additional wire to probe inside since the contacts are fairly deep in the connector so normal probe tips won't reach the contacts inside. If you can't get a reading try to probe between the output pins on the BMS's output XT60 (not the one that has the battery connected to it but rather the one that connects to the container)
If voltage is present then your BMS is functional, you can repeat the jumper process to turn the BMS off again. Verify it has by checking the output voltage again.
If you can't get any voltage reading the BMS is most likely dead.
@Lia Sorry for the delay response. I finally have a day off from work to test it out. I've included a video link, please check it out. I'm still a little confused. I've got myself a wire, and found the holes where the pins is supposed to go. I understand that you have a wired voltmeter connected to the board. In my case- I don't. When I probe the wire where it's supposed to go, what am I looking for as indication?
I've included a video with audio explaining what I've done so far. If you can review it and tell me what's missing that would be great.
Sorry again, I'm really bad at this. Thanks for your help!
@Vietrider802 No worries, had a look at the vid :)
If you can't probe your multimetre into the small holes in the black and white controller connector you can probe off the output terminals on the XT60 BMS side.
I took one of your pics and annotated the ones you want to probe in volt mode. It might be best to probe within the connector since the connectors on the PCB are covered in a layer of protective coating that helps prevent corrosion via moisture and small amounts of water. Be careful not to short the terminals or your probes when doing this else it could blow the BMS.
As there are 2 XT60's I labelled the one the battery goes in which we can ignore, that should always have voltage present on it. The other connector should only present around 43.5v and 63v (depending on charge level) if the BMS is told to turn on via that blue wire being connected to ground. It's a toggle so it doesn't need to be held in, only touched to trip it on and off as per my vid.
Presumably when you connect that blue pin to ground on the black and white connector it should put voltage across that XT60 thus proving the BMS fine and pointing towards an issue further up maybe with the switch itself.