Euy ebike issue.

S

SweetTrade324

Member
Region
USA
I bought a Euy branded ebike from Amazon. I opens up the controller box and it said it was a 500w controller. The bike is supposed to be 750. I complained and the refunded 100. My question is how much does this actually affect the bike performance? I would upgrade controller but it won’t fit in the box. Should I sell it and get a true 750 or isn’t it worth it. It a
Accelerates slow and has low torque but top end is 31mph.
 
Why sell, you have the claimed performance and an extra C-Note
Controller power rating ( and size determinate ) is amps likely ~18A - 22A and matched to your battery discharge capability.
Check the motor model number for digits '500' or '750'
 
Think of the controller as a keyboard. A mickey mouse keyboard on a high end computer is going to limit the capabilities of the computer, right?

The controller contains all of the programming required to operate a PAS type system. Examples of the programming might be how far the pedals need to be turned prior to the throttle working or how soon the power to the motor is turned on. The controller programming also controls the speed the bike runs at in each PAS level - and more.

Finally, the capacity of the controller may or may not restrict the motor's ability to get power from the battery. Thus, using the 500 watt motor as an example, a 15a controller is going to pass about 750 watts at wide open throttle. That same scenario, all else being equal, with a 20+ amp controller, will allow 1000+ watts through to the motor. Speaking from experience, 1000w feeding a 500w motor is going to result in some pretty "sporty" performance. Nothing exotic, but you had better be hanging on with both hands! The downside to all that extra capacity feeding a 500w motor, is you're going to need to use your head. The motor is designed for 500w. Anything over that is going to cause "stuff" to get warm quickly. You should be fine crossing a road for example, or getting a little extra boost to climb a short hill or catch up to a riding buddy. Think seconds though, not minutes....

2 points. First, depending on your performance expectations, that controller is likely fine. 2nd, an aftermarket controller is like replacing the mickey mouse board with a higher end keyboard on the high end computer.
 
AHicks said:
Think of the controller as a keyboard. A mickey mouse keyboard on a high end computer is going to limit the capabilities of the computer, right?

The controller contains all of the programming required to operate a PAS type system. Examples of the programming might be how far the pedals need to be turned prior to the throttle working or how soon the power to the motor is turned on. The controller programming also controls the speed the bike runs at in each PAS level - and more.

Finally, the capacity of the controller may or may not restrict the motor's ability to get power from the battery. Thus, using the 500 watt motor as an example, a 15a controller is going to pass about 750 watts at wide open throttle. That same scenario, all else being equal, with a 20+ amp controller, will allow 1000+ watts through to the motor. Speaking from experience, 1000w feeding a 500w motor is going to result in some pretty "sporty" performance. Nothing exotic, but you had better be hanging on with both hands! The downside to all that extra capacity feeding a 500w motor, is you're going to need to use your head. The motor is designed for 500w. Anything over that is going to cause "stuff" to get warm quickly. You should be fine crossing a road for example, or getting a little extra boost to climb a short hill or catch up to a riding buddy. Think seconds though, not minutes....

2 points. First, depending on your performance expectations, that controller is likely fine. 2nd, an aftermarket controller is like replacing the mickey mouse board with a higher end keyboard on the high end computer.
Click to expand...
So if I upgrade my controller from 500w 15a to 500w 20a (750w won’t fit) I should have higher performance?
 
SweetTrade324 said:
So if I upgrade my controller from 500w 15a to 500w 20a (750w won’t fit) I should have higher performance?
Click to expand...
Yes, your motor would be getting an extra 250 watts. But let's back up just a second. Are we talking about a KT controller? If so, there are other benefits to making that move. Stuff many people enjoy way more than just a little extra performance....
 
Here Is a photo
 

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What about the 20a controller you mentioned "would fit"?
 
I was going to suggest that there very likely is no direct replacement with additional capacity.
 
SweetTrade324 said:
Oh? Why is that of what you said about more amps producing more wattage?
Click to expand...
Not clear on your question here?
MANY e-bikers have upgraded their controllers for both higher performance and more refined/state of the art controller programming. Both are clearly desirable.

The downside is, these new controllers must be adapted to your bike. There are no directions, though many find them not THAT complicated, and there is NO assurance that the controller wiring ends will match what your existing controller is using. You'll need to match the new controller to your bike. There's a lot of online support available, but it's still going to involve some head scratching...

Here's a link that will show some of the available models in the KT lineup I mentioned earlier (I'm a big KT advocate). I'm giving it to you not to order from, but to give you an idea of what's available. MOST of these are also available on e-bay and/or Amazon. You WILL need a new KT display to go with the controller. There is NO option available that will use your existing display.

www.aliexpress.com

17.93US $ 28% OFF|Bulu Ebike Kt Controller 36v 14a 22a 250w 500w 48v 25a 30a 750w 1000w 1500w Waterproof Electric Bicycle Controller With Light - Electric Bicycle Accessories - AliExpress

Smarter Shopping, Better Living! Aliexpress.com
www.aliexpress.com www.aliexpress.com
 
SweetTrade324 said:
I bought a Euy branded ebike from Amazon. I opens up the controller box and it said it was a 500w controller. The bike is supposed to be 750. I complained and the refunded 100. My question is how much does this actually affect the bike performance? I would upgrade controller but it won’t fit in the box. Should I sell it and get a true 750 or isn’t it worth it. It a
Accelerates slow and has low torque but top end is 31mph.
Click to expand...

SweetTrade, I recommend you read this very good article on Motor Power Ratings

Futility of Motor Power Ratings

"There's no such thing as a rated watt!" Read here for why we don't advertise a simple power rating for the motors we sell. Also, have a look at our Youtube video where Justin talks about the power to propel bicycles in <a href="https://www.youtube.com/watch?v=ALde6zhLPs0">"School of Watts"</a>.
ebikes.ca ebikes.ca

Your controller is rated at 15 (+-2 amps). I am assuming you have a 48V battery. 48 Volts X 15amps = 720 Watts (+- 96 watts) delivered to the motor. The rating of the controller "should" be the amount of amps the controller can handle on a continuous basis, without overheating, assuming constant ambient temperature, and consistent cooling. It is not the same as how many continuous watts/amps that will be delivered to your motor for the duration of your ride.

Like all of my controllers, your controller probably will deliver a burst of amps for a short period of time that is higher than the "continuous" rating. This is the "peak rating" of your controller which is not published. If you factor in the "+-2 amps" potential in the controller rating, that leaves you with at least possibly a burst of 17 amps which is 816 watts. Also, your battery starts out at 51 to 53 volts, not 48. At that state of charge you could get 795 to 901 watts. As your battery voltage diminishes on your ride, you will not even get to 700 watts at some point on your ride. I have a Luna Z1 with a 30 amp controller that delivers at least 1590 Watts when I start out my ride. By the end of my ride, when I'm down to 42 volts on my battery, the battery BMS, or the motor controller limits me to 500 watts maximum, so that I can "limp" home. That's the way it usually works.

I recently added a 17 amp rated KT controller to my wife's Aventon bike, The display shows bursts of up to 980 watts, but 17 amps X 48 volts is only 816 watts.

Also , no matter how powerful the controller rating is, it will be limited by the battery BMS output. If you have 50 amp controller, but your BMS is limited to 20 amps, you are only going to get +-20 amps.

Welcome to the arcane side of ebikes!
 
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