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fourthewin

Just had first wreck, unexpected shutdown on 14C

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Posted (edited)

Thankfully, I didn't break anything and for the most part I'm very lucky, just nicked up. It trashed the trolley handle and put some big scraps in it even through the bumper tape.

I really don't know what happened guys....I was cruising at about 13-14mph and got behind some bikers. They moved out of the way and I went to pass them going up a slight hill, and accelerated to about 16mph. I wasn't going super fast, I wasn't powering up the hill hard, and the bastard just cut-off and dumped me. I had been monitoring my battery as I was getting close to the 50% mark but it hadn't dipped to to 50% or below yet. I wanted to go easy and run the battery down to around 20% for battery maintenance. 

I thought the Kingsongs specifically were designed to not do this. It's kind of scary if it just randomly cuts off like that. 

Any ideas to the cause? I was able to get back home in one piece and it ran ok the rest of the way back but I was going pretty slow. 

Here's some photos: 

 

 

IMG_1967.JPG

IMG_1968.PNG

IMG_1969.PNG

Edited by fourthewin
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Posted (edited)
14 minutes ago, Hunka Hunka Burning Love said:

How much do you weigh and how steep of a hill was it?  What tire PSI and what battery watt hour size are you running?  Was it pretty cold outside?  Even though you had 50% battery, going up a hill can tax the wheel by drawing extra current to keep you going as the load demand is higher on the motor.  The safe cruising speed on level ground can be different than the safe cruising speed going up an incline.  Also I hear that the KS14's can overheat clmbing hills (@Cloud where ya be man?) so you have ot be careful of a shutdown.  If you have a good phone case, you can try monitoring the battery level indicator as you go uphill to see where it drops down to.

I try to imagine the battery level sort of like a rubber band.  It varies when you're riding and on how much demand you place on the motor in terms of acceleration and climbing.  A measurement while stationary doesn't factor in the draw on the battery as compared to rolling around or up a hill.  Try to imagine a tungsten filament light bulb attached to a battery.  It glows at a certain brightness when turned on.  Now imagine attaching 10 more light bulbs to the same battery and see how bright it shines.  Now imagine if the battery is at 50% charge.  How bright will the 10 bulbs shine as compared to one bulb?  At some point of adding bulbs they may not light at all.  Not exactly a perfect analogy, but it kind of makes sense.  I'm sure @esaj has a better one up his sleeve.  :whistling:

Agreed.
KS14s will overheat going up too steep of a hill and just shut down.

OP; was there any beeping while going up the hill?

Allen

Edited by abinder3
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Posted (edited)

@Hunka Hunka Burning Love Thank you for a detailed response. 

Let's see if I can answer your questions. 

  1. If using this chart it's probably a 12.5% "grade" (don't be confused with the blue degree lines)
  2. I am 200lbs. 
  3. I run at 50psi on the tire
  4. It's roughly 70 degrees outside and the sun was setting. I was wearing a pullover which protected me a bit. 
  5. This one has the 680whr battery
Edited by fourthewin
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The King Song 14D has a max speed of about 17mph (according to the King Song web site).

I don't know what the max speed of the 14C is though.

Have you ever encountered 'tilt back'?  If you haven't, maybe you mistook the 'tilt back' for shutting down.  Some people do get confused with the 'tilt back' and think it's shutting down on them.

(just some thoughts.)

 

Allen

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8 minutes ago, abinder3 said:

Agreed.
KS14s will overheat going up too steep of a hill and just shut down.

OP; was there any beeping while going up the hill?

Allen

That's the thing....NONE! While I hit the beeping a lot when cruising (Speed limit is set to 26mph, 27, 28, 29), there was ZERO going up this, I simply wasn't going fast enough! 

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2 minutes ago, abinder3 said:

The King Song 14D has a max speed of about 17mph (according to the King Song web site).

I don't know what the max speed of the 14C is though.

Have you ever encountered 'tilt back'?  If you haven't, maybe you mistook the 'tilt back' for shutting down.  Some people do get confused with the 'tilt back' and think it's shutting down on them.

(just some thoughts.)

 

Allen

Oh yes, but this was a full blown shut-off. I knew what happened the second my foot hit the ground and went into damage control. Lol

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Just did some searching on the internet and supposedly, the 14C has a max speed of about 15mph.  You stated that you think you were going 16mph uphill.  Sounds like you may of encountered 'tilt back' or it shut down because you were pushing it too hard.

(again, just a thought)

 

Allen

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Just now, fourthewin said:

Oh yes, but this was a full blown shut-off. I knew what happened the second my foot hit the ground and went into damage control. Lol

You may of tried to accelerate too hard going up a hill at 50% battery.
(and again, just a thought)

 

Allen

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5 minutes ago, abinder3 said:

Just did some searching on the internet and supposedly, the 14C has a max speed of about 15mph.  You stated that you think you were going 16mph uphill.  Sounds like you may of encountered 'tilt back' or it shut down because you were pushing it too hard.

(again, just a thought)

 

Allen

Not sure where you are getting getting your information. Kingsong's own marketing material shows 30kph (18.6mph). See here. Additionally, ewheels shows it as 19mph. See here

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1 minute ago, fourthewin said:

Not sure where you are getting getting your information. Kingsong's own marketing material shows 30kph (18.6mph). See here. Additionally, ewheels shows it as 19mph. See here

The 14C here:
https://www.wheelers-store.com/en/product/king-song-14c/

 

The 14D here:
http://www.kingsong.com/upload/file/contents/2016/12/5858f66961eca.pdf

 

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4 minutes ago, fourthewin said:

Not sure where you are getting getting your information. Kingsong's own marketing material shows 30kph (18.6mph). See here. Additionally, ewheels shows it as 19mph. See here

Your like says "around 30kph".

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4 minutes ago, abinder3 said:

Neither of these are the official kingsong website which is www.szkingsong.com. 

Thanks for the info though. 

4 minutes ago, Hunka Hunka Burning Love said:

12.5% grade is fairly steep.  @Tilmann where is that Rockwheel hill climbing video at that abandoned German military base showing the different grades?

Also going downhill can be perilous... 

 

I'll take some more photos tomorrow. I could be wrong, but I don't think it's very steep. 

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2 minutes ago, fourthewin said:

Neither of these are the official kingsong website which is www.szkingsong.com. 

Thanks for the info though. 

I'll take some more photos tomorrow. I could be wrong, but I don't think it's very steep. 

Ummm............ Yes, the first one is an official King Song web site.

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Posted (edited)

I think this is a 13% grade:

007.jpg

https://humofthecity.com/2012/02/04/san-francisco-hills-and-grades/

Keep in mind some of these rated speeds are for a certain rider weight and might be maximum speeds at which failure occurs instead of what a "safe" riding speed is rated at.  For example, my Ninebot has maximum speed I believe of 30 KPH.  I can safely cruise on a flat road at about 22 KPH when tiltback occurs so I have about 8 KPH spare speed just in case I shoot past that 22 KPH for whatever reason (fast acceleration, downhill, gust of wind on my back).  I do not expect to be able to hit 30 KPH safely as torque reaches zero at that point so it cannot balance me any further.

If I were 200 or 110 pounds instead of 167 pounds in weight, I'd expect the performance of the wheel to vary a bit as the load on the battery and motor would be different.  For example If I was 400 pounds I don't think my Ninebot could move me safely at 22 KPH... Riding these wheels is a multi-factored equation where lots of variables come into play.

Edited by Hunka Hunka Burning Love
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4 minutes ago, abinder3 said:

Ummm............ Yes, the first one is an official King Song web site.

*facepalm*. Ok. Thanks. 

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5 minutes ago, fourthewin said:

*facepalm*. Ok. Thanks. 

Sorry, I meant the 2nd one.
(If you look under the "Contact" page, you will see that it is.)

 

Allen

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Posted (edited)

One experiment to try is to get on a wheelbarrow and while sitting directly over the wheel, have someone roll you around on flat ground.  Head towards a 12.5% hill and see how much energy it takes for that same person pushing you to move you uphill at the same speed or while trying to accelerate.  Moving 200 pounds of rider around isn't too bad on flat ground, but going uphlll will be a way different story!  That may be why some newer Kingsong firmware tends to cut performance at lower than 50% battery levels.  Unless you have a mega watt hour pack, the draw up some hills could be too much for the wheel and components.  They could be trying to avoid this exact situation that fourthewin experienced.

EDIT:  Ohh :w00t2: found it...

 

Edited by Hunka Hunka Burning Love

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Posted (edited)

Sounds like a shutdown due to too much power demand? Do the Kingsongs have a 80% (or so) warning? Though I can see a bump/obstacle being enough for going from below 80% to over 100% in an instant.

Also, never believe manufacturer or dealer speed declarations (even ewheels is exaggerating some numbers, e.g. ACM top speed). The safe speed is the speed where the default ( and unlocked for KS) alarm beeps start.

Well, lucky you didn't get hurt. Yellow wheel looks really nice btw:)

edit: a neat idea may be, look at the used power (W) when going at speed limits (1st and 2nd beep) while on flat ground. Then, compare that wattage to going uphill, possibly slower. Not sure if you get helpful results, but it's an idea. Unless someone tells us this won't give anything useful, I plan to do that too.

Edited by meepmeepmayer
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2 hours ago, Hunka Hunka Burning Love said:

12.5% grade is fairly steep.  @Tilmann where is that Rockwheel hill climbing video at that abandoned German military base showing the different grades?

Also going downhill can be perilous... 

 

@Hunka Hunka Burning Love here'ya go:

 

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21 hours ago, Hunka Hunka Burning Love said:

 

Any wheel can cut out like that if it overheats ...

Nothing should overheat quickly--the batteries, ESC, and motor all have a lot of thermal mass.

Doesn't the wheel start doing a tilt back as the temperature gets high before cutting out completely?  If not, why not?

 

 

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