How I Swapped out my Ecotric 20" fatbike 810LED and controller.

If you're comfy with splicing, it's pretty easy.

Some people have purchased the controller with a complete harness, including throttle, brake levers, new PAS sensor and display. You replace everything. Just a matter of cramming it all under the pedals. It's around $110. If one were to do that, might as well get a 25A controller. It won't fit under the pedals, but you can buy a case for $9 and mount it on the frame.
Thanks Harry. I have some dexterity issues so splicing is out of the question. I would do a 25amp with the plastic case ..based on your concerns with water tightness on the 20 folders in a post long ago.

Anyway, it might be brake sensors and will deal with those in the morning, disconnecting them at the controller.

I was hoping you would respond, thanks 😊
 
Anyone know which controller is in the FAT20S900 version (it is the version with the S900 and 48v)? I ask because my mom would rather have the Ecotric Dolphin since it is step thru, but it doesn't come with the S900, which appears to provide better PAS control. Thus, my thought is to use the same controller as the FAT20S900 if the pinout is the same to simplify the install and avoid the splicing, soldering, etc on the Dolphin.
 
If you're comfy with splicing, it's pretty easy.

Some people have purchased the controller with a complete harness, including throttle, brake levers, new PAS sensor and display. You replace everything. Just a matter of cramming it all under the pedals. It's around $110. If one were to do that, might as well get a 25A controller. It won't fit under the pedals, but you can buy a case for $9 and mount it on the frame.
As it turns out it was not brake sensors. Ecotric , without hesitation , sent me a new controller. I consider that pretty nice of them, let alone it's great customer service.
 
As it turns out it was not brake sensors. Ecotric , without hesitation , sent me a new controller. I consider that pretty nice of them, let alone it's great customer service.
What was wrong with your controller? Do you have the Dolphin? Thx.
 
You should buy the S900 and also the controller from the same vendor together. There are s900's and s900's. and they may use different firmware in them.

It's not clear that they are plug compatible between the FAT20810 and FT20S900. I would expect it, so they could use same brake levers, throttle, and PAS sensor, as well as the motor cable. Otherwise, inventory control is messy. What you need to do is make sure they will even sell you a s900 and controller.

Someone on the Facebook Ecotric page said he was buying the S900, but he never elaborated. I believe he said it was $150. Now you're at $900-1000. Maybe you should buy a Lectric step thru.
 
Thanks Harry. I'll most likely go with your setup since you've detailed such excellent instructions, but will search a bit more for the S900 + compatible controller. If I find one, I'll post it here too.
 
What was wrong with your controller? Do you have the Dolphin? Thx.
Ecotric Dolphin. Just installed the new controller, smaller in physical size ( no spec info on unit) and had two unused grey wires. Anyway, Ecotric, as I mentioned, helped me fix the problem. I recomend their product and company if anyone is considering a folder.
 
You should buy the S900 and also the controller from the same vendor together. There are s900's and s900's. and they may use different firmware in them.

It's not clear that they are plug compatible between the FAT20810 and FT20S900. I would expect it, so they could use same brake levers, throttle, and PAS sensor, as well as the motor cable. Otherwise, inventory control is messy. What you need to do is make sure they will even sell you a s900 and controller.

Someone on the Facebook Ecotric page said he was buying the S900, but he never elaborated. I believe he said it was $150. Now you're at $900-1000. Maybe you should buy a Lectric step thru
Not the speed limiter? Do they mate with each other?
No they didn't far as I can tell. Both had female connectors. Sure was easier putting the controller and wires back in the stock under pedal compartment. I included a photo
 

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No they didn't far as I can tell. Both had female connectors. Sure was easier putting the controller and wires back in the stock under pedal compartment. I included a photo
Thanks for the photo. That's helpful. Does the new controller support an LCD? If so, is it the S900 or KT-LCD3?
 
Thanks for the photo. That's helpful. Does the new controller support an LCD? If so, is it the S900 or KT-LCD3?
I got the controller from ecotric, my original had failed. I simply did a plug and play. I offered a display upgrade to my wife and she declined, go figure :)
 
Would you mind sharing the dimensions of your original controller? Thanks. I've not yet purchased the Dolphin, but am trying to figure out which controller to place in it. If I go with something other than the KT controller (i.e. I'm looking for the same connectors as the original), I'll post it here.
 
Would you mind sharing the dimensions of your original controller? Thanks. I've not yet purchased the Dolphin, but am trying to figure out which controller to place in it. If I go with something other than the KT controller (i.e. I'm looking for the same connectors as the original), I'll post it here.
Better yet, what are the dimensions of space where the new controller would fit? Thanks.
 
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