CRAZY throttle problem!!!

Howie

New Member
Region
USA
I've got a stealth bomber clone. 72v with 8000w. It has a Sabvoton mq con 72150(m) controller. Generic no brand name full twist throttle from ebay/China. Panasonic battery.

So here's the problem:

~No throttle response and no throttle response from the pedal assist.

This is actually the second time I've had this problem. Sort of. The first time was slightly different. The first time this happened it was temperamental. Either no throttle at all or pedal assist at all or I would give it a little throttle/pedal and it would go to full acceleration uncontrollably and not stop until hitting the brakes thus activating the cutoff. Either one or the other with no in-between. Either full throttle or no throttle and it was like it had a mind of its own. And when it would go into spastic mode, the brake cutoff was the only thing that stopped the motor from spinning, shy of cutting the ignition. But soon as I let off the brake the bike is going full throttle again uncontrollably. The first time this happened I opened her up and I thought I had found a crimped wire. But while I had the bike open I changed the half twist throttle to a full twist one, and low and behold when I put the bike back together, the problem was fixed. So whether it was the throttle or what I thought was a crimped wire, was left undetermined specifically.

~Well, now I've just got no throttle and no throttle response from the pedal assist.

I've got a green flashing light on the controller that flashes 30 times. Well, it flashes continuously, but after 30 flashes there's a slight pause. So I'm assuming that's 30 flashes.

If I disconnect the hand throttle the green light stops flashing. And if I keep the hand throttle disconnected and turn the bike off and back on, the pedal assist returns to function perfectly. But then if I reconnect the hand throttle (with the power still on), guess what, the initial problem starts again with the motor spinning uncontrollably as I mentioned above when I had the "first" issue. Brakes do stop the motor via the cutoff, but as soon as I release the brakes the motor is at full acceleration uncontrollably, just like the first time. If I then disconnect the hand throttle (with the power still on), the motor stops. But if I barely touch the connection together again, the motor starts again uncontrollably. So I turn the bike off. Reconnect the hand throttle. Start it up again. No throttle and no pedal assist. Repeat the process and it does the whole thing I just explained over again.

Is the problem the throttle or the controller? Or is there something wrong in the parameters settings? If it's the throttle, why do I keep burning them out?

SOMEONE OUT THERE PLEASE HELP?!?!?!?
 

Attachments

  • s-l1600 (1).jpg
    s-l1600 (1).jpg
    40.5 KB · Views: 34
  • s-l1600.jpg
    s-l1600.jpg
    99.9 KB · Views: 31

scrambler

Active Member
If it is a 3 wire throttle (-5V, +5V, Signal) you can try the following
1- Disconnect and measure between the plus and minus (controller side) to see if you get the proper 5VDC voltage from the controller.
2- Next, only connects the + and - 5V with the corresponding throttle side, and measure between the -5V and the Signal, and check what voltage you get, at zero and max throttle. A hall throttle would be around 0.8V (at zero) and 4.2V (at max). A potentiometric throttle could be 0-5V.

1- Should tell you if the controller power supply is correct
2- Should tell you if the throttle signal is good
If both 1 and 2 are good, it would point to a controller processing error.
 
Last edited:

Howie

New Member
Region
USA
If it is a 3 wire throttle (-5V, +5V, Signal) you can try the following
1- Disconnect and measure between the plus and minus (controller side) to see if you get the proper 5VDC voltage from the controller.
2- Next, only connects the + and - 5V with the corresponding throttle side, and measure between the -5V and the Signal, and check what voltage you get, at zero and max throttle. A hall throttle would be around 0.8V (at zero) and 4.2V (at max). A potentiometric throttle could be 0-5V.

1- Should tell you is the controller power supply is correct
2- Should tell you if the throttle signal is good
If both 1 and 2 are good, it would point to a controller processing error.
THANK YOU!!! Really appreciate the response!
 

Howie

New Member
Region
USA
Well, I replaced the throttle and she's running again. Took it on a 35 mile ride with no apparent problems. So now the question begs to be asked, why am I burning up throttles. This is the 3rd one. The only other thing I noticed is that I charged it till the light turned green on the charger, but when I started the bike up it did not have a complete charge. It was at about 87%. So not sure what this is all about, but I have it on the charger now and we'll see what happens in a few hours. Really hoping we don't have a new problem....
 

scrambler

Active Member
Have you checked what is the Voltage going to the throttle, and compared that to the voltage spec of the throttle you are buying?
 

Howie

New Member
Region
USA
I did not. But all of these parts are foreign and you never really know if what the seller advertised or even what it says on the packaging/label is legit in regards to these numbers. The tag on the battery says 72v, so I got a throttle from a seller whose item was listed as 72v compatible.
 

Merle Nelson

Well-Known Member
Region
USA
If it is a 3 wire throttle (-5V, +5V, Signal) you can try the following
1- Disconnect and measure between the plus and minus (controller side) to see if you get the proper 5VDC voltage from the controller.
2- Next, only connects the + and - 5V with the corresponding throttle side, and measure between the -5V and the Signal, and check what voltage you get, at zero and max throttle. A hall throttle would be around 0.8V (at zero) and 4.2V (at max). A potentiometric throttle could be 0-5V.

1- Should tell you if the controller power supply is correct
2- Should tell you if the throttle signal is good
If both 1 and 2 are good, it would point to a controller processing error.
Where do you live Scrambler? I want you for a neighbor!!! 😃

My wife's name brand ebike has been down for over two months now. The very nice and well meaning bike shop owner is also very new to the business. His method of diagnosis has been to unplug electric parts and plug in known good parts while frequently checking in with main office techs.

The whole time I'm wishing he was also a multi meter guy with a book of voltages and values to be checking for.
 

scrambler

Active Member
I did not. But all of these parts are foreign and you never really know if what the seller advertised or even what it says on the packaging/label is legit in regards to these numbers. The tag on the battery says 72v, so I got a throttle from a seller whose item was listed as 72v compatible.
The battery voltage has nothing to do with the throttle. What matters is the controller and how it is programmed.
Most controllers work in the 0-5V range signal for the throttle. But some throttles could be using a higher voltage, then using a few resistance to take it down into that range.

To be sure you either need to get the info from the manufacturer (the one who sold you the bike , and the one who sells you the spare), or a forum with people who have the same bike (Endless Sphere comes to mind), or measure things on the bike.