Help ebike stutters after 5 min of riding .

Iv'e been building a large ebike based off a Chinese clone of the stealth / vector frame ,It has a 3000w rear hub motor and a controller paired with a Kt-lcd3 . The bike always starts out perfect ,it's feels powerful enough to just trow you down the street . After 3 to 5 min it has this weird issue when if i pull the throttle it starts to go for about 1/10th of a second then stops , if i do this a few times and pull the throttle back slowly it starts to go again until i have to stop . What could cause this ? Can this bee caused by a setting in the lcd ? If so which setting should i change and what to ?

The battery is a 72v 18650 based pack i built myself from harvested cells , i have already taken it apart , tested each cell and recharged it finding no issue's .

A 60A max controller using 18650's that probably have lots of sag in them. My guess is you're hitting the LVC. What does the voltage drop to when it cuts out? You may be able to lower the LVC with the LCD settings. That may get you some relief, but I'd guess your battery pack sags a lot as does most 18650 cells under heavy amp draw. Either that or your controller could be overheating and the thermal protection cutting in.

i've been thinking LVC but the pack doesn't sag that much , the cells are inr18650 13q they are rated for up to 30 amp discharge 15 amp continuous , I'm running them at less than 3.75 amps.
Low voltage protection on the controller is supposed to be at 60v and my pack has never been below 72 even with the throttle pulled under load. The lcd controller i have been given is the 72v kt-lcd3 , could there be some setting that could cause this ?

Did you solve this?
The KT user manual can be downloaded and has all the programming info in it. C12 is the LVC parameter.
You might find it at www.szktdz.com, (get an up to date version cause there are several out there)
Lots of other stuff in it as well.

kdog said:

Did you solve this?
The KT user manual can be downloaded and has all the programming info in it. C12 is the LVC parameter.
You might find it at http://www.szktdz.com, (get an up to date version cause there are several out there)
Lots of other stuff in it as well.

Click to expand...

It's still doing it , i tried to change the lvc settings i think it's the lcd since it controls all of it . The version of the lcd says 72v but unless there is a special version of the manual they do not have on that site 72v is never even mentioned in it only up to 48v. I set the controller on real time voltage and it still does this , i'm going to go over the settings one at a time to see if anything changes . I emailed the company and asked but have not received back a reply . This is pissing me off because the bike is fun as hell to ride .

I was having hell trouble configuring this motor/KT controller. Ran like crap on the stand, noisy motor shuddering etc. I'm checking halls/phases/ wiring for hrs- nothing. Then I spent hrs going through the motor parameters ... Made it worse :? Hardly ran.
With nothing to loose I hit factory reset... Ran Perfect Arrrrgh!
Different prob to yours but...
Try it?

You got it right but with one difference , mine does not reset like it supposed to. When i got the bike they actually gave me a disk showing me how to put it together and gave me the manual for the lcd so the first thing i did was reset it and try to configure it for 72v . No matter what i did it would reset everything except the settings that had to do with the battery , I got a second display plugged it in and it worked with no problems . After confirming the lcd issue for shits and giggles i set the lcd's up to transfer settings and now my first lcd works . This puzzles me and im just going to replace it with a sw-900 or a ll-tft because i hate this lcd anyway . It limits the speed to 42 which would be ok but it seems to limit my acceleration to do it . Anywho Thanks to everyone who helped with this .

hi, was wondering what you ended up doing re thr stuttering? sounds like you have a similar setup to mine which is a yuyangking 60 amp (golf cart controller) 3kw china motor but i have thr lei-li tft.
i have had same issues with stuttering from time to time with my first battery build which was samsung 30q 6s 15p.
i have since rebuilt the pack and found a lot less issues although seems to do it when getting hot.
as for the tft its a wierd one as the max speed only applies to the throttle so set to 10mph and usingthrottle it does 10mph but start pedalling and itll do 50-60mph!!!
also temp reading is normally around 360celcius and the odometer doesnt work...
my opinion stick with your lcd mate.

just thought id throw my experience in....having said all that its a total grin to ride and i love it...just rest it to cool it off regularly.

oops just looked at your controller......its not putting enough amps out i think.....when i lower my amp output mine stutters like mad. i modified thr shunt and was outputting enough to kill the first parrallel row on my battery (around 100amps) it ran perfectly, doesnt seem to like being limited.
could be wrong though.
dan

Wind82 said:

Iv'e been building a large ebike based off a Chinese clone of the stealth / vector frame ,It has a 3000w rear hub motor and a controller paired with a Kt-lcd3 . The bike always starts out perfect ,it's feels powerful enough to just trow you down the street . After 3 to 5 min it has this weird issue when if i pull the throttle it starts to go for about 1/10th of a second then stops , if i do this a few times and pull the throttle back slowly it starts to go again until i have to stop . What could cause this ? Can this bee caused by a setting in the lcd ? If so which setting should i change and what to ?

The battery is a 72v 18650 based pack i built myself from harvested cells , i have already taken it apart , tested each cell and recharged it finding no issue's .

Click to expand...

With my BMSBattery 48V Panasonic battery pack and the LCD3 I had exactly the same problem with my Q100H..until I learned my battery should not be fully loaded up to 54,4V ..at 48V everything is going fine.

Hunza said:

With my BMSBattery 48V Panasonic battery pack and the LCD3 I had exactly the same problem with my Q100H..until I learned my battery should not be fully loaded up to 54,4V ..at 48V everything is going fine.

Click to expand...

Keep in mind that a 54.4v (13s) pack is at best half full at 48v...so you're carrying around twice the weight / capacity than you're actually using.