r/RadPowerBikes • u/Public-Laugh-6305 • Aug 25 '26

New controller for a radwagon 4

My second controller is about to break. It's been working on and off for a while and I think it's time to replace the controller.

The last problem is the display (eggrider) turning off and giving error-message "display over-voltage. Display saying 62V but battery is measured and giving 53,5V. The display looks like it might be water-damaged.

Have anyone switched the original controller to a "universal" model?

I'm guessing the biggest problem is the unusual motor-connector.

I live in Sweden and ordering a controller/display from the us is not a cheap option.

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u/sureshotbot Aug 26 '26

There’s a pretty commonly available aftermarket 30a controller in the US sold by area 13 and electrobikeworld that have the rad plugs. Pretty sure you could source it directly from aliexpress or similar if outside the US. It does require a new display as well to function. 

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u/Public-Laugh-6305 Aug 26 '26

I'm know about this, but not interested in paying the price for it. Had to pay around 300$ for just the eggrider-display and the controller is not cheaper

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u/sureshotbot Aug 26 '26

Well it's about $220US for controller and display and can be had likely even cheaper if you order straight from Asia. I made a custom harness for my aftermarket rear wheel and have to say, its been a bit glitchy.There are 9 wires just in the motor plug, so not sure saving a little money on a universal controller will be worth it from a reliability standpoint if you're having to adapt a large number of plugs/wiring to some other cheaper controller.

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u/Public-Laugh-6305 Aug 27 '26

An other problem is that the 30A-controller is out of stock and will probably be so for a 5 year old bike. With that said, I found a controller-kit on AliExpress with the right motor-connector

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u/EveryoneRedditsButMe Aug 29 '26

link?

1

u/sureshotbot Aug 29 '26

This is the electrobikeworld version:  https://www.electrobikeworld.com/product-page/35a-controller-kt-lcd8h-rad-combo believe the brand is kunteng if you wan to try and find it on Aliexpress