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35amp controller and KT-LCD8H display/battery/power issue - Radwagon 4 - help!

Started by Kavskops, October 07, 2023, 02:45:41 PM

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Hello Everyone,

I recently received my 35amp controller and display, however something's not firing up.  See attached pictures of the display.  I've researched and troubleshooted away but nothing's working.

Here are the issues:

1, The display won't stay on unless I keep my finger pressed on the power button.  When I let go, the display turns off.
2, There is no power from the system, when I turn the throttle nothing happens.   
3, The display indicates no power from the battery, yet the battery is fully charged.

I'm attaching two pictures, one for each time I set up the system - I get a zero battery graphic with an 08.9 volts reading the first time I set up the system and a zero battery graphic the next time with a 65.4 volts indicator, so something has changed between the first set up and the second. 

I have gone back to stock controller and display and and everything works fine.  Battery shows 100%. 

Again there is no power from the throttle with the new set up.

There are no bent pins, everything connects fine, and there can't be any wrong wiring as it's pretty much a like for like swap, although there was one additional wire in the box which seems to be for the display (green), but I have enough length as is, and trying that wire doesn't change anything.

Any help appreciated.  Thank you in advance, and happy thanksgiving.


What battery do you have that is reading 64v?  What does it read on the other controller/screen?

Have you tried it without the lights and breaks hooked up?  If it works there then plug in one at a time to know where the fault is. 

Where did you buy the controller?  If it Area13 they are great about helping you troubleshoot.

Good luck


Hi Inoxa,

Thanks for the reply, 

It's the standard 48volt battery, so why I am getting 65v (and/or 8v) is beyond me. I have tried all those suggestions, and nothing is working, although I am stubborn enough to try again! :-).  I got it from Affordable Ebikes.  Myles at Affordable Ebikes wrote me back just before the holidays, and I I'll no doubt hear back from him next week, but it has affected my confidence of using these mods.  I've read continually how easy it is etc etc, then mine doesn't work.  I commute on this bike and so I need total confidence in the system I am using.  I'd love to get it up and running but that the display doesn't even stay on is an issue!   


on the stock controller it reads 52v?

If that is the case, then it could be the new controller or it might be the new screen.
You have checked everything. 

What light do you have?  Some lights can burn a controller out.  I think even one of the stock lights have been doing that to upgraded controllers.  Hopefully not but if you get a replacement I would try it without hooking up the light. 

Are you sure you have a controller that is compatible with your model?  I know they were in short supply.  I know my controller wouldn't work with your model.   


Thanks Inoxa,

From the research I've done the controller is compatible and is the standard upgrade.  I switched back to the stock set up, just to give me the bike to ride to work, but now I have a E30 Maintain message so from hoping to have an upgraded bike, I now have a bike that doesn't work at all.  I have isolated the E30 message to the pedal assist, you can undo the cable and use the throttle only, but that's no good for how I ride. 

Everything looks fine in terms of pins, connections etc, so honestly, I really have no clue what the issue is now.

From what I've read the E30 message could be more serious. 

Thanks so much for your response - and to answer your questions....yes I did isolate the lights with the new set up but nothing worked in addition to the lights.  It was like the new set up just didn't work and did something to upset the stock set up.

I need a beer.


Quote from: inoxa on October 08, 2023, 02:57:38 PMWhat light do you have?  Some lights can burn a controller out.  I think even one of the stock lights have been doing that to upgraded controllers.  Hopefully not but if you get a replacement I would try it without hooking up the light. 

That's very good advice for those with a 35A controller upgrade, which includes me.  Both Area13 and ElectroBikeWorld have confirmed that any headlight upgrade (including the optional Rad "premium" headlight) can, and eventually will, burn out the upgraded controller, by trying to draw more power than the controller can deliver on that circuit.  Neither could supply me with a wattage rating for the upgrade controller's headlight circuit, but I believe the stock light is 5w and the "premium" around 8-10w.

I only carry the wired headlight as a backup to the wonderful Planet Bike rechargeable light up on the handlebar, but I'm still pretty peeved about this - why would these controllers be worse than stock in that respect?  Sounds like the designers screwed up and didn't consider we might upgrade our headlights as well as our motor-power delivery.  So I had to revert all the way back to the original crappy headlight shipped with my MiniST2 to protect my 35A controller.  Grrrrr......   >:(
Shucks Ma'am, I'm no "Hero Member", I just like to wear this cape.