KS14S Tilt-back After Full Charge - Help

[Marty Backe]

I normally don't leave my wheels charging for extended times, but I forgot about my KS14S for a day or so as it sat on the charger.

Today I attempted to ride it but it instantly tilts-back. Also, as I move the wheel back and worth, my phone continually buzzes. I don't recall ever having my phone vibrate as I operated the KS14S (or any other wheel).

I have this feeling that I've read about this situation before, but can't remember and of the details or fix.

I'm leaving the wheel on right now to see if the problem goes away as the battery is discharged.

Does anyone know what's going on. @KingSong69?

[Scott Henley]

Hmm as far as I know (and I could be wrong ) but once the batteries are full power stops being sent to the wheel does it not ? I accidentally left my 14D in charge for like 12hrs. When I realized what I had done I went to the power brick and it was cold . Normally very hot when charging so I assumed like iPhone and other lithium batteries that it knows when to stop charging even when still connected to power . 

[kasenutty]

Overcharge maybe? Some guys had trouble with that. 

[Scott Henley]

10 minutes ago, kasenutty said:

Overcharge maybe? Some guys had trouble with that. 

That’s what I was thinking as well. Just seems odd that it would be allowed to overcharge . I know some guys on the onewheel forum have similar issues . They discharge the battery as much as possible , try to run it down to ~10% and recharge . It balanced the cells out and the problem goes away usually . But easier said than done on a 14s. Onewheel gets 7mi . So running that out is not so bad . Running out an 840wh battery attached to a wheel that doesn’t really want to go is a different story . 

[Paddylaz]

30 minutes ago, Marty Backe said:

Also, as I move the wheel back and worth, my phone continually buzzes. 

Wait, what?!

[kasenutty]

4 minutes ago, Scott Henley said:

That’s what I was thinking as well. Just seems odd that it would be allowed to overcharge . I know some guys on the onewheel forum have similar issues . They discharge the battery as much as possible , try to run it down to ~10% and recharge . It balanced the cells out and the problem goes away usually . But easier said than done on a 14s. Onewheel gets 7mi . So running that out is not so bad . Running out an 840wh battery attached to a wheel that doesn’t really want to go is a different story . 

 

People here have had the same problem with a 16s. I think the guy from Texas with the dog pic had the problem. 

[Marty Backe]

40 minutes ago, Scott Henley said:

That’s what I was thinking as well. Just seems odd that it would be allowed to overcharge . I know some guys on the onewheel forum have similar issues . They discharge the battery as much as possible , try to run it down to ~10% and recharge . It balanced the cells out and the problem goes away usually . But easier said than done on a 14s. Onewheel gets 7mi . So running that out is not so bad . Running out an 840wh battery attached to a wheel that doesn’t really want to go is a different story . 

If I have to get the battery down to 10% I may as well throw the wheel away as it would take days probably.

Someone please add this to the KingSong fail statistics 

[Scott Henley]

1 minute ago, Marty Backe said:

If I have to get the battery down to 10% I may as well throw the wheel away as it would take days probably.

Someone please add this to the KingSong fail statistics 

 

Mum sure someone will come along with some better advice . Or maybe it will just start miraculously working if you leave it powered on for a while ..

if you decide to throw it away ...be sure to toss it in my trash can . ?

[steve454]

1 hour ago, kasenutty said:

 

People here have had the same problem with a 16s. I think the guy from Texas with the dog pic had the problem. 

@Circuitmage ?

[kasenutty]

Yes, for some reason I think the control board needed to be replaced, but not 100%

[Rehab1]

2 hours ago, Marty Backe said:

I normally don't leave my wheels charging for extended times, but I forgot about my KS14S for a day or so as it sat on the charger.

 

Are you using Jason’s KS digital fast charger? If so was it set at 100%? 

Edited March 8, 2018 by Rehab1

[steve454]

@DaveThomasPilot had that problem also, ended up getting a new board but the thread ended without him saying that it fixed the problem.  Something was said about the voltage detection on the board was faulty.

[DaveThomasPilot]

Yes,

The new card actually reports a lower voltage that what I measure on a DVM.  But, that doesn't really cause a problem.  Maybe, speed throttling would occur at a higher battery voltage than necessary, but I've not noticed that.

I'm guessing they are using high value resistors to scale the battery voltage down to a voltage a chip on the control board can measure.  And they failed to recognize the non-zero input current of that chip.

But that's just a guess.  There were several people who had the exact same symptoms.

You can use a charge doctor to terminate the charge at a lower voltage and eliminate the problem and the cost of a little range.  

[DaveThomasPilot]

Also, it took several days for the battery to discharge enough to eliminate tiltback, turned on with just the lights on.

After this happened the second (or maybe the third) time, I tried starting at the bottom of hill and riding up.  I could go up the hill just fine, but couldn't ride on level ground until I'd gone up the hill many times (and walked down).  A real pain!

So, charge doctor (or new control board) is what you need, I"m afraid.

[outcast00096]

3 minutes ago, DaveThomasPilot said:

Also, it took several days for the battery to discharge enough to eliminate tiltback, turned on with just the lights on.

After this happened the second (or maybe the third) time, I tried starting at the bottom of hill and riding up.  I could go up the hill just fine, but couldn't ride on level ground until I'd gone up the hill many times (and walked down).  A real pain!

So, charge doctor (or new control board) is what you need, I"m afraid.

I've been looking into this on the OneWheel forums because I wanted to make sure I knew what I was talking about before I said anything. FM (maker of Onewheel) has been recommending to their riders that they leave their OneWheel on charge all the time if they are not riding now (which sounds crazy to me). However, they do mention in the manual that charging overnight or 24 to 48 hours is good because it "rebalances" the cells. The OneWheel app actually shows you the status of your cells and they usually go back to normal after a good 1 to 2 day charge. Why mention this? You don't have to run down to 10% because that's where the OneWheelers are before they are told to rebalance. You should be rebalanced now and you shouldn't have to discharge to 10% at all.

Notwithstanding, a phenomenon I used to experience on the Tardis (my OneWheel) was regen warnings. I couldn't charge anywhere near 100% because of the hills where I live. Immediately when I started to go I would get buzzes on my phone and it (my OneWheel app) would warn me that the board would shut down if I continued regen'ing the board. I never got to the point but I have heard of others nose-diving (motor shut off) because they had too much regen. They had pushback too or tiltback to us. So I'd agree with Dave. I've never had a regen warning since I switched to EUC's but it sounds like Wheellog might be giving you one. I was going to dig through the code on Github to see if I could find instances of it but I'm at work and can't open the repository right now. However, it sounds like your wheel thinks you're charging the board too much. (I'm assuming you are using Wheellog from previous posts).

[DaveThomasPilot]

I looked up some of the old threads on the subject (below).

I actually used light bulbs to discharge the battery and compare the voltage reported by the wheel to DVM readings.  Also, recorded charge and discharge curves.

I ended up having three different KS14C control cards (thanks Jason!), none of which reported battery voltage accurately.  I finally concluded that the control board thinking the battery voltage was lower than it actually was didn't cause much of an issue.

 

 

 

 

[Marty Backe]

46 minutes ago, outcast00096 said:

I've been looking into this on the OneWheel forums because I wanted to make sure I knew what I was talking about before I said anything. FM (maker of Onewheel) has been recommending to their riders that they leave their OneWheel on charge all the time if they are not riding now (which sounds crazy to me). However, they do mention in the manual that charging overnight or 24 to 48 hours is good because it "rebalances" the cells. The OneWheel app actually shows you the status of your cells and they usually go back to normal after a good 1 to 2 day charge. Why mention this? You don't have to run down to 10% because that's where the OneWheelers are before they are told to rebalance. You should be rebalanced now and you shouldn't have to discharge to 10% at all.

Notwithstanding, a phenomenon I used to experience on the Tardis (my OneWheel) was regen warnings. I couldn't charge anywhere near 100% because of the hills where I live. Immediately when I started to go I would get buzzes on my phone and it (my OneWheel app) would warn me that the board would shut down if I continued regen'ing the board. I never got to the point but I have heard of others nose-diving (motor shut off) because they had too much regen. They had pushback too or tiltback to us. So I'd agree with Dave. I've never had a regen warning since I switched to EUC's but it sounds like Wheellog might be giving you one. I was going to dig through the code on Github to see if I could find instances of it but I'm at work and can't open the repository right now. However, it sounds like your wheel thinks you're charging the board too much. (I'm assuming you are using Wheellog from previous posts).

Thanks. I'm using the KingSong app. Can't ride on my flat driveway. It's not a regen problem.

[Hunka Hunka Burning Love]

Maybe if you can support the wheel at an angle (sloped blocked under the pedal supports or rope tie from rafter?), and let it run for a while at moderate speed that might help run the battery down below the alarm tiltback overcharge detection level.  Or maybe turn it on with the light on with music playing through the BT speakers for a while until you can get a new control board or use a Charge Doctor.

[steve454]

It's a strange problem, only Kingsong seems to have this overcharge problem.  It sounds like the undercharge behavior of most wheels, that tilt back so far that they are unrideable, protecting the batteries from overdischarge.  I wonder if the Kingsong problem is similar to the low battery behavior of the Huanxi in this video?  At the end the battery got so low that the wheel tilted back so far that it was unrideable.   

I wonder if it is the battery management system is what is the bad part.  I'm thinking it's the BMS, not the control board or charger.  Maybe it's one of the battery packs.  But which one?  Someone mentioned measuring each battery separately to check if one had significant voltage difference.  Skip to 2:08 to see the tiltback.  Also look at the yellow KS14B to the lower right of the thumbnail, I think it's the same one that @Stan Onymousbought in the store closing sale.

 

Edited March 9, 2018 by steve454

[steve454]

2 hours ago, DaveThomasPilot said:

Also, it took several days for the battery to discharge enough to eliminate tiltback, turned on with just the lights on.

After this happened the second (or maybe the third) time, I tried starting at the bottom of hill and riding up.  I could go up the hill just fine, but couldn't ride on level ground until I'd gone up the hill many times (and walked down).  A real pain!

So, charge doctor (or new control board) is what you need, I"m afraid.

So, is it working good now?  Do you only charge to 90%?  It is starting to seem like a problem I had (and at least one other) I had on my Ninebot S1 that was delivered with almost dead batteries.  For the first 3-5 charges, battery number 2 would show way too high of a charge when the charger went green, then would discharge a lot farther than battery number 1 after a ride.

After awhile the app showed that both batteries stayed almost identical after charge and after rides.

I never got a tiltback from overcharge, though.

So far I put about 30 miles on the S1 in total, it seemed fine the last couple times.  Then the cold and rain came so haven't ridden it for about a month.  It's at about 50% right now.

[steve454]

14 hours ago, Marty Backe said:

Thanks. I'm using the KingSong app. Can't ride on my flat driveway. It's not a regen problem.

Sounds like a board problem.

Edited March 9, 2018 by steve454

[outcast00096]

5 hours ago, Marty Backe said:

Thanks. I'm using the KingSong app. Can't ride on my flat driveway. It's not a regen problem.

Yeah. I misspoke because I was at work. I meant overcharge only brought up regen charge as an example of my phone buzzing because of overcharge.

[Milli Zhao]

Hi @Marty Backe, hi everyone, I reported the issue to engineers today, got below solution:

1. our electric unicycle batteries are with over charge protect function inside, similar to mobile, normally won't have any problem even charge 48hours or longer time (even over charge constantly).

2. when the voltage shows on App over 69v, there will be buzzer or voice notice"over voltage"

3. when voltage shows on App above 69v, pls do as follow: 1）record the real voltage shows on App,  2） open the e-unicycle, use a multimeter to check the voltage of the battery packs, 3) compare the two voltage dates, if the gap exceed 0.5v, then need to replace the mainboard. If the gap within 0.5v, no need to care, just restart the device, voltage will turn to normal.

4. if there is over voltage problem, it's not casued by over charge, it's caused by components on mainboard functionally, in fact it's was components influenced unnormally by environment  (return the mainbaord to factory to replace the components can fix the problem )

@Marty Backe, can you check the voltage of the battery packs and tell me the datas? Thanks.

[Circuitmage]

@steve454 No, sounds like a different problem. My 16S issue was that every 2 or 3 miles, mine would just start shaking and when I went to pick it up it would go full speed until I layed it on it's side (power button did not turn it off). 

Also, I have left my 16S on charger ~8 hours after full, and the battery pack is nice and cold and shuts off as it should, so very happy with the 16S charger.

 

Edited March 9, 2018 by Circuitmage

[Marty Backe]

3 hours ago, Flora Yuan said:

Hi @Marty Backe, hi everyone, I reported the issue to engineers today, got below solution:

1. our electric unicycle batteries are with over charge protect function inside, similar to mobile, normally won't have any problem even charge 48hours or longer time (even over charge constantly).

2. when the voltage shows on App over 69v, there will be buzzer or voice notice"over voltage"

3. when voltage shows on App above 69v, pls do as follow: 1）record the real voltage shows on App,  2） open the e-unicycle, use a multimeter to check the voltage of the battery packs, 3) compare the two voltage dates, if the gap exceed 0.5v, then need to replace the mainboard. If the gap within 0.5v, no need to care, just restart the device, voltage will turn to normal.

4. if there is over voltage problem, it's not casued by over charge, it's caused by components on mainboard functionally, in fact it's was components influenced unnormally by environment  (return the mainbaord to factory to replace the components can fix the problem )

@Marty Backe, can you check the voltage of the battery packs and tell me the datas? Thanks.

Thank you for the additional information.

I left the wheel on overnight, with the lights on. The battery level dropped from 98% to 93%. There was no change to the wheel.

I will have to open the wheel this weekend to do the test.

This is my first KingSong wheel failure