XR battery dead after 4km, any ideas?
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Hey, I put together a Onewheel XR from spare parts of about 4 different boards due to budget constraints.
I finally finished the build and was super happy to ride it just to find out that after just 4km the boards tells me it needs to be charged. I rode past pushback at very low speed and the board cuts off after a few meters. If I open the app, the board shows the battery at 85%. My firmware/hardware configuration doesn’t show battery voltages.
Any idea what could be the problem?
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@bulletxtime Hiya, What hardware and software version is your XR controller running?
If it's not the latest you can try connecting it to the OWCE app to get that data back and check. -
@lia hi Lia! Unfortunately it's a hardware/firmware configuration that won't allow it. Here's an update, I charged the board for the past 72h to balance the cells and went for a test ride, I could not go more than 100 metres before I got the "Need some juice" message.
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@bulletxtime Sounds like a definite hardware issue. How far apart have you taken this board considering it was made from parts? Just wondering how confident you would be measuring the cells manually with a multimeter.
Otherwise it might be worth checking https://www.stokelifeservice.com/ to see if there are any repair places nearby that can take a look. -
@lia thanks for your reply! I'm very confortable taking it appart. I was planning to measure the cell voltage next as part of the diagnostic process but wanted to ask the pros before doing anything. I'll get on it right now, I also have an owie chip that I have on hand that I will be installing for deeper stats. Will update with results!
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@bulletxtime Good luck! Let us know how things go with it :)
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@lia So I installed the owie chip but now I get an error 16. I did not have that without the chip. Not sure how to fix it..
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@bulletxtime E16 is a breakdown in communication between the BMS and controller. The green and white wires specifically.
The OWIE chip sits between them so it might be worth checking those wires are the correct way around and that the OWIE chip is working.
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@lia I'll check the wires again. Also I test the total battery voltage and it gave me 43.4V even though the OW app said 100%...
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@bulletxtime 43.4v is really low for an XR! Like that's below the low voltage cutoff for the 15 series cells all together. 43.4/15=2.89v per cell. 3v is the cutoff.
Each cell should be anywhere between 3v and 4.2v. Together in series between 45v and 63v.
A new battery is probably the safest bet. If you want to dig deeper you could probe the balance connector between cells to see if it's a single bank of cells that just died or the whole pack is bad in which I would assume the BMS might not be good.
Did all the parts definitely come from an XR and not a Plus?
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@lia I tried plugging the OWIE chip to PC but I get nothing. I think it's dead.
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@lia here is a reading of all the cells from the balance connector:
C1 = 2.68
C2 = 3.06
C3 = 2.64
C4 = 3.06
C5 = 2.70
C6 = 3.05
C7 = 3.07
C8 = 3.09
C9 = 3.08
C10 = 2.70
C11 = 2.71
C12 = 3.05
C13 = 2.70
C14 = 3.07
C15 = 2.70I'm sure the battery (it says 15s2p on it) and controller (the app shows it as XR) came from an XR. The BMS I bought with the controller but the guy also gave me a set of OW+ rails. Could it be that the BMS was from a OW+ and that's why it doesn't charge?
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@lia So I checked the wires of the owie chip twice. I also pressed reset on it why trying to connect it to my phone because it wasn't blinking.
I then decided I would cleanup my wires and replaced a bunch of Frankenstein wires. Plugged everything back in without the owie chip and now the board correctly shows 1%... I have no idea why it was showing 100% before and now 1%. It's charging now so I'll let it fully charge for a few days and I will update.
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@bulletxtime That's some good news! Hope you can get those cells back above LVC :)
Do you have a pic of the BMS in question. Just so I can see if it is the right one. I'm sure it is since you'd run into all sorts of other compatibility issues long before riding but good to check. -
@lia Of course! It's charging so I didn't unplug anything. Will take better pics later if needed.!
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@bulletxtime Yeah that one's fine :) Definitely not a plus BMS thankfully.
Fingers crossed it works out fine!
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@lia I'll keep you posted! Thanks for your help.!!
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@bulletxtime Welcome ^-^
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@lia Alright, after charging to 100%, here are the new cell readings:
C1 = 4.08
C2 = 4.10
C3 = 4.08
C4 = 4.10
C5 = 4.08
C6 = 4.10
C7 = 4.10
C8 = 4.10
C9 = 4.10
C10 = 4.09
C11 = 4.09
C12 = 4.10
C13 = 4.09
C14 = 4.10
C15 = 4.09Total 61.5
Would you consider this balanced?
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@bulletxtime That's balanced enough. There is a little cell degradation since they should peak at 4.2 but that's expected for an old used battery so I'd say that's good to ride! :)
