r/DIYonewheel

Back in March I recieved an older OW2114xxxxxx Pint (5313 hw and 5040 fw) with a known bad battery. The board had sat for at least 2 yrs, but I was able revive the battery and balance the cells enough to get it back riding.

They would balance to 62.6v (4.18 ea) but then 2 of the cells would lose voltage pretty quickly. Clearly 2-4 bad cells (last picture).

I was able to use this as an extra/driveway board for friends...but had to constantly rebalance the cells after each session...while also closely monitering battery temp to <130F.

After the latest rebalance, the board will show 62.6v and then immediately drop to 22.5v and die when unplugged...but individual cells still show 4.17+...

Battery is obviously shot and I would like to replace the battery w an OnlyAmps or Nexus to extend the range...but am worried the BMS may be shot too.

Any thoughts on how to bench test a BMS?

They seem hard to come by and I dont really want to buy a whole new FW pack for $300...rather go aftermarket battery and use my existing BMS, if possible.

Appreciate any help/experience.

So it was all for nothing. It all works, the whole thing. I rode on it for maybe 2 minutes total (I'm still not good, but that’s not the problem) and it works. Motor spins, imu works right, it’s got lights and power and everything. But it’s unusable. The FUCKING foot sensor it shit. I've spent like 100 bucks on sensors total (about 1400 cad total on the whole thing so far and it’s missing paint and a few 3d prints). The sensor has a few problems. I'm now gonna talk about them a little, and if you don’t care or don’t think you can really help me with that, you can skip ahead​. It ghosts like crazy, so I can’t heel lift, and if I just jump off it goes reverse in full speed (the rear bumper is fucked). I don’t know if it’s normal, but when pressure is applied on one side of the sensor, the voltage on the other side also goes up. This is a huge issue, because the sensor works in this weird way where it doesn’t detect pressure in a linear way. It’s either at 0V, 1.1V, or 3.3. (Sometimes I catch it at 1.9 or smth but basically it doesn’t really detect the amount of pressure on it, it just switches on or off). The other issue it has is that it’s extremely hard to set off. If I press on it with my finger, it snaps to 3.3V, but when it’s on my foot pad and I put my foot on it, it barely ever registers 3.3V. And since both zones kind of share their voltage (and stick like crazy), it’s a total nightmare either to activate or deactivate depending on the setting I choose in vesc tool. There is no sweet spot though, it’s only in the extremes. Theres a bunch more to say about it, so if you wanna try to debug it with me, Ill be glad to give you all the info you need. [[[[[SKIP HERE]]]]]. Now I'm at a crossroads. I could blow anlther 200 dollars in an exile sensor array or something just for it to have the same fucking problem. I'm already over budget. I'm 16 and I can’t find a fucking job. I'll take all the help I can get. Please, if you know of cheap, proven to work sensors for vesc onewheels, help me out and send the link. I'm actually turning insane because the entire thing works except this one stupid part that turns out to be really important. I will forever be grateful for you if you help me. I'd get a tatoo of your username fr. For now I guess I cam ride with simple stop, since that eliminates the risk of the blard going rogue, but that'd be like building a jetpack and only using it to go from your kitchen to your bedroom. Thanks for reading. I don’t think I'll kms, but if I could for like one week that would be sick.

When I press on the ADC1 foot sensor, the voltage on the other one goes up, even though there is no load on it, and vice versa. It that normal? For example, then one reaches 2.5V, the other is at least at 1.3V. My board has had some issues with ghosting. Could that be why? I had cheap square sensors but am switching them out for the big spintend one. Hope it doesn’t have the same issue. Could it also be an issue with the way I sauldered the connector?

When I run detection it barely spins and makes this sound. It never has. It’s like theres sand in it or something😭 My onewheel has taken a 2 meter fall into a concrete staircase before cause the foot pads where sticking, but I tested it after and it still worked, so how could the fall have a delayed effect of breaking the motor? Please tell me you've seen this before and you can help

It just doesn’t spin. I get on it, both sensors engaged, but it doesn’t fire up. When I spin it vesc tool sees it and says it’s got some speed though. I opened my board up and the 3 phase cable aswell as the hall sensors seem to be connected just fine. With vesc tool i can control the motor and when I tell it to spin it buzzes, kind of like haptic feedback, but doesn’t spin. I haven’t had smoke of anything come out of it, and ive never really ridden the board since it’s been built for 3 days. I'm also bad at riding, so ive never gone fast on it (im talking never more than like 4 kmh). There is one time though when my sensor stuck and my board flew at about 15kmh into a 2m downwards concrete staircase where it got scratched up, but still worked fine after. It’s only now that I was messing with ADC voltages and fault stop that it stopped. Also refloat seems to think it’s upside down all the time. I really don’t get why it doesn’t spin anymore. Any ideas?