brushless Dc motor controllers

 1 µW
 Posts: 1
 Joined: Dec 27, 2017 1:29 am
 Contact:
brushless Dc motor controllers
I have a 1500 watt conhismotor (hallomotor) mounted in a 20"x 4" fatwheel..the controller it came with in the kit is junk in my opinion ...ive wasted quite a bit of money basically from not knowing what im doing i hate to admit..anyway im wanting advice to if i can achieve 30 mph at 48 volts with the right controller..or do i need to take it up to 60 or what..im ready to purchase a new controller but need to know also if i need to buy s higher voltage battery as well...any help with my stupudity on the issue would be greatly appreciated jim

 1 GW
 Posts: 3287
 Joined: Aug 10, 2008 8:28 pm
 Location: Chicagoland nw suburb Mt. Prospect IL. USA
Re: brushless Dc motor controllers
In most cases a controller will not increase your speed.
What speed are you achieving with 48v and is it 48 nominal or 52?
Does the controller have a 3 speed switch?
Dan
What speed are you achieving with 48v and is it 48 nominal or 52?
Does the controller have a 3 speed switch?
Dan
 Drunkskunk
 100 GW
 Posts: 7059
 Joined: Apr 14, 2007 11:37 am
 Location: Dallas, Texas. U.S.A.
Re: brushless Dc motor controllers
A motor's speed is based on the voltage supplied. And the speed is basically linear. If 10 volts gives you 10mph, 20 volts will give you 20mph. 100 volts will give you 100mph.... as long as you also have enough amps to cover the wattage needed to go that speed.
If you take the battery voltage you have now, and divide it by your current speed, then multiply that number by the speed you want to go, it will give you the battery voltage you need to reach that speed.
For example..if you have a 48 volt battery, and you can go 22mph, and you want to go 30...
48volts / 22mph = 2.181818.. (this is in volts per mph)
2.181818 X 30mph = 65.45454 volt
So you need a 66 volt battery to do 30mph, if those were the numbers you started with. You'll have to fill in your own current voltage and top speed.
Additionaly, you'll need a battery and controller that can handle 1000 to 1500 watts output to be able to go 30mph.
If you take the battery voltage you have now, and divide it by your current speed, then multiply that number by the speed you want to go, it will give you the battery voltage you need to reach that speed.
For example..if you have a 48 volt battery, and you can go 22mph, and you want to go 30...
48volts / 22mph = 2.181818.. (this is in volts per mph)
2.181818 X 30mph = 65.45454 volt
So you need a 66 volt battery to do 30mph, if those were the numbers you started with. You'll have to fill in your own current voltage and top speed.
Additionaly, you'll need a battery and controller that can handle 1000 to 1500 watts output to be able to go 30mph.
Buy the ticket, take the ride.
Monster Bike:https://endlesssphere.com/forums/viewto ... =6&t=38667
Monster Bike:https://endlesssphere.com/forums/viewto ... =6&t=38667
Re: brushless Dc motor controllers
Buy a 72V 800W controller from ebay seller hksunwinJimsorenson wrote: ↑Dec 27, 2017 1:44 amIthe controller it came with in the kit is junk in my opinion
wanting advice to if i can achieve 30 mph at 48 volts with the right controller
im ready to purchase a new controller
You wont be able to use the KT Display with it.
Also your battery, need more info. Where did you buy it, whats it Ah rating, whats it discharge rating. Maybe you can scavange it and rebuild it to make it 72V
Re: brushless Dc motor controllers
A good controller can get more speed than described here... but you're talking a few 100 $ then, not $35. Look for a controller that is 'FOC' and can do fieldweakening.Drunkskunk wrote: ↑Dec 28, 2017 4:57 pmA motor's speed is based on the voltage supplied. And the speed is basically linear. If 10 volts gives you 10mph, 20 volts will give you 20mph. 100 volts will give you 100mph.... as long as you also have enough amps to cover the wattage needed to go that speed.
If you take the battery voltage you have now, and divide it by your current speed, then multiply that number by the speed you want to go, it will give you the battery voltage you need to reach that speed.
For example..if you have a 48 volt battery, and you can go 22mph, and you want to go 30...
48volts / 22mph = 2.181818.. (this is in volts per mph)
2.181818 X 30mph = 65.45454 volt
So you need a 66 volt battery to do 30mph, if those were the numbers you started with. You'll have to fill in your own current voltage and top speed.
Additionaly, you'll need a battery and controller that can handle 1000 to 1500 watts output to be able to go 30mph.
 dogman dan
 100 GW
 Posts: 34681
 Joined: May 17, 2008 12:53 pm
 Location: Las Cruces New Mexico USA
Re: brushless Dc motor controllers
You aren't stupid, just new. Of course you expected 30 mph, and in 26 inch wheel and regular tires with 60 psi in them, you would just get that when the battery was very full. They just don't tell you in the ad that a fat soft tire and smaller diameter will cost you speed.
Just curious, what speed are you getting to? surely still close to 25 mph right out the gate, and 20 later on?
It could be also related to your battery. If your 48v, which I assume is charged to 54.6v, sags 8v under load, then you are running in effect, 40v. A stout battery that sags only 2v under load will go much faster.
But your smaller wheel is costing you a bit of top speed too, along with tire drag if you are running 10 psi or whatever. In general, you'd expect 2527 mph with a hard skinny tire. But a soft fat one, another few mph gone.
I would think that 2000 watts will be enough power, but you might still have to bump up to 18 cells in series battery, (64v) or even 20s 72v to get the top speed you want, and not take forever to build up to that speed.
Good advice above to spend a bit on a higher volts controller, and enough amps to reach 2000w peak. Look for one with a broader range of voltages, like 4872, and 30 to 40 amps.
Chances are though, your current battery can't even begin to handle more than 20 amps. so you need to ride slow awhile, till you are ready to ante up for the faster bike. Think another $500, or more.
Just curious, what speed are you getting to? surely still close to 25 mph right out the gate, and 20 later on?
It could be also related to your battery. If your 48v, which I assume is charged to 54.6v, sags 8v under load, then you are running in effect, 40v. A stout battery that sags only 2v under load will go much faster.
But your smaller wheel is costing you a bit of top speed too, along with tire drag if you are running 10 psi or whatever. In general, you'd expect 2527 mph with a hard skinny tire. But a soft fat one, another few mph gone.
I would think that 2000 watts will be enough power, but you might still have to bump up to 18 cells in series battery, (64v) or even 20s 72v to get the top speed you want, and not take forever to build up to that speed.
Good advice above to spend a bit on a higher volts controller, and enough amps to reach 2000w peak. Look for one with a broader range of voltages, like 4872, and 30 to 40 amps.
Chances are though, your current battery can't even begin to handle more than 20 amps. so you need to ride slow awhile, till you are ready to ante up for the faster bike. Think another $500, or more.
Frankenbike longtail
https://endlesssphere.com/forums/viewto ... cing+betty.
bolt on longtail https://endlesssphere.com/forums/viewt ... =6&t=74584
The mixte long tail. https://endlesssphere.com/forums/viewt ... =6&t=74384
Beach cruiser converted to long tail. https://endlesssphere.com/forums/viewt ... r#p1045572
https://endlesssphere.com/forums/viewto ... cing+betty.
bolt on longtail https://endlesssphere.com/forums/viewt ... =6&t=74584
The mixte long tail. https://endlesssphere.com/forums/viewt ... =6&t=74384
Beach cruiser converted to long tail. https://endlesssphere.com/forums/viewt ... r#p1045572