Thanks! Did you modify the controller yourself? or bought it off market? I am not so worried about the battery life as I have enough time to recharge my battery everyday. And I use only 15 miles a day. What I am after is increasing speed with the existing equipments, use the maximum potential of the current setup. I don't mind getting a new controller but not keen on spending for a new battery or motor. Currently I get 17-18 mph on peak battery. Would be nice if I can achieve 20mph by increasing the controller Amp.
Please suggest a compatible Controller for my bike
- Thread starter CrazyBikes
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Deleted member 4366
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I get my knowledge from trying things, not from being on the forum for a long time.Perhaps you would know better than I do, just because you have been around here long enough
your setup is already optimized, it won't go much faster even when you replace the controller with a stronger one.
The limiting factor in this case is the motor (8-Fun SWXH) itself. 18-19mph is the most it can go up to.
The 8-Fun SWX02 motor is the next model up (24-25mph), after that, the 8-Fun BPM (23-25mph with higher torque). For higher speed still, you will need a direct drive motor.
To get higher speed with the same motor, you'll need a 48V setup. Overvolting will wear out your motor in no time.
Your controller is made by Lishui. For a compatible controller, look for LSW947 but it's difficult to find one with the same connectors.
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So, have you tried 8-Fun BPM 36V250W with 20A controller? If yes, what is the outcome of 8-Fun BPM 250W with a 20A controller compared to a 15A controller, according to your experience?
Yes, I have ridden BPM bikes with 20A controllers. As I have indicated, you can easily get to 22-24mph with BPM motor and 20A controller.
the 8-Fun BPM 36V 250W is an OEM version for building road legal bikes, it has the same power as the normal BPMs which are made in 36V 350W or 48V 500W.
One point about the 20A controller: Lishui make sine wave controllers with 6 FETs (15A or 17A) or 12 FETs (25A-30A). The Lishui 20A controller has 9 FETs and is square wave. Yours is already best match, SWXH + 15A sine wave controller.
the 8-Fun BPM 36V 250W is an OEM version for building road legal bikes, it has the same power as the normal BPMs which are made in 36V 350W or 48V 500W.
One point about the 20A controller: Lishui make sine wave controllers with 6 FETs (15A or 17A) or 12 FETs (25A-30A). The Lishui 20A controller has 9 FETs and is square wave. Yours is already best match, SWXH + 15A sine wave controller.
Thanks! But I did not understand what do you mean by best match? 20A won't make a difference on my or @CrazyBikes motor?
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Deleted member 4366
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That's easy. 33% more torque.
The BPMs are marked with their speed code. If you tell me the markings, I'll tell you how fast it can go.
Depending on which speed code you have, increasing the current probably won't affect the top speed.
22 amps is the sweet spot for 250w/350w BPMs.
The 500w BPM can go to about 35 amps at 36v. Normally, 25 amps at 48v gives you all the power you need for an electric bicycle, which is quite convenient, because that's about the present maximum for a 09 bottle battery, which means about 8kg for the total kit.
The BPMs are marked with their speed code. If you tell me the markings, I'll tell you how fast it can go.
Depending on which speed code you have, increasing the current probably won't affect the top speed.
22 amps is the sweet spot for 250w/350w BPMs.
The 500w BPM can go to about 35 amps at 36v. Normally, 25 amps at 48v gives you all the power you need for an electric bicycle, which is quite convenient, because that's about the present maximum for a 09 bottle battery, which means about 8kg for the total kit.
with a stronger controller, your bike will climb hills better but won't go faster on flat roads. The downside is more wear on the motor. Your current setup runs cool.
Crazybikes all my controllers are stock ones that came with kits or upgraded ones no mods done so far and all my bikes are either 262 or 700c.
17- 18 is good for your little folder and is probably the most your system can manage with those small diameter wheels, if you had 26" or bigger wheels then you could go 20ish + with the correct gearing. In reality you need a bigger bike which will feel safer at higher speeds, as been mentioned amps will not increase top speed you need volts, amps will improve pulling power that includes standing starts.
You could try different gearing combo's bur trying to spin small wheels fast isn't easy.
17- 18 is good for your little folder and is probably the most your system can manage with those small diameter wheels, if you had 26" or bigger wheels then you could go 20ish + with the correct gearing. In reality you need a bigger bike which will feel safer at higher speeds, as been mentioned amps will not increase top speed you need volts, amps will improve pulling power that includes standing starts.
You could try different gearing combo's bur trying to spin small wheels fast isn't easy.
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Crazybikes forgot to mention about your controller replacement, you may be be able to get one but not with those moulded connectors as they will be a Volt/Bafang design manufacturing requirement. I see two options open up your controller and mod the shunt or if you got another compatiable controller desolder and resolder all the connector wires to the pcb.
Thank you all very much for your thought and sharing your experience. So, seems like for 20" wheeler current setup is best.
Now, what is my option to upgrade this bike to gain some speed? Its already been mentioned that upgrading to 48V & a new motor would be ideal. But to keep expenses low, if I upgrade the motor ONLY to a 500W BPM, and get it replaced with some bike shop, would that make any difference in speed?
Now, what is my option to upgrade this bike to gain some speed? Its already been mentioned that upgrading to 48V & a new motor would be ideal. But to keep expenses low, if I upgrade the motor ONLY to a 500W BPM, and get it replaced with some bike shop, would that make any difference in speed?
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It might be slower or faster, depending on which one you fit. What is it exactly that you're trying yo achieve? Torque, speed or both, and do you want to start with a new bike or modify your existing one? What's your budget?
Changing your motor won't hange anything. The speed and power are limited by the controller.
A different controller will release the speed limit and you can tweak it for a bit more torque.
A new 48v battery and controller will get you even more speed and power.
A new motor and controller will also get more speed, but not a lot more torque.
Speed depends on power. You can get a motor that can spin to 30 mph, but if you don't give it enough power to reach that speed, it'll run ineficiently and probably overheat. The controller, motor and battery all need to match the speed that you want to go.
Changing your motor won't hange anything. The speed and power are limited by the controller.
A different controller will release the speed limit and you can tweak it for a bit more torque.
A new 48v battery and controller will get you even more speed and power.
A new motor and controller will also get more speed, but not a lot more torque.
Speed depends on power. You can get a motor that can spin to 30 mph, but if you don't give it enough power to reach that speed, it'll run ineficiently and probably overheat. The controller, motor and battery all need to match the speed that you want to go.
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Now, what is my option to upgrade this bike to gain some speed? Its already been mentioned that upgrading to 48V & a new motor would be ideal. But to keep expenses low, if I upgrade the motor ONLY to a 500W BPM, and get it replaced with some bike shop, would that make any difference in speed?[/QUOTE]
Riding down hill will make it go faster and others will tell you that going over a cliff you may hit 100mph. As said have a look at your gearing by upping this you should be able to peddle beyond the cut off point.
Riding down hill will make it go faster and others will tell you that going over a cliff you may hit 100mph. As said have a look at your gearing by upping this you should be able to peddle beyond the cut off point.
I am trying to achieve more speed. It would be good to have an explanation what torque does
, sorry for my ignorance. I am not a very fit cyclist and have some issues with knee, so can't push a lot. So, I need to have enough speed without having to a push a lot. Usually I push the throttle and pedal at the same time, so it goes easy on my knee.RE: my budget, Just because I have invested a lot on the bike already, i would not want to go over 150 inclusive whatever change I make.
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Deleted member 4366
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It sounds like you want more torque rather than speed. If you release the speed limit, the power will be the same, so it will be just as hard or easy to pedal. Torque is the force in the wheel from the motor that moves your bike. The more torque you have, the easier it is to pedal.
You can increase the torque fairly easily on most controllers. Remove the 4 screws from the end-plate, the end opposite where the wires come out. Take a photo of what's in there, like this:
You can increase the torque fairly easily on most controllers. Remove the 4 screws from the end-plate, the end opposite where the wires come out. Take a photo of what's in there, like this:
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What I meant about gearing was you count the teeth on the front chain ring and also the teeth on the high and low gear at the rear and see if you can get more peddling speed by changing them to a different size, however in your case with dodgy knees not a good idea.
It sounds like you want more torque rather than speed. If you release the speed limit, the power will be the same, so it will be just as hard or easy to pedal. Torque is the force in the wheel from the motor that moves your bike. The more torque you have, the easier it is to pedal.
You can increase the torque fairly easily on most controllers. Remove the 4 screws from the end-plate, the end opposite where the wires come out. Take a photo of what's in there, like this:
Also somewhere you wanted to know the code on the motor. So here it is....
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Deleted member 4366
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That's the serial number of the motor. Is there nothing written between the spoke flanges?
Unfortunately, your shunt is not directly behind the end-plate. It's probably lying along the pcb under or near the main capacitor. If you want to do this mod, you'll need to slide the pcb out, which means removing the 4 screws in the other end and the three in the side, then photo from above.
Unfortunately, your shunt is not directly behind the end-plate. It's probably lying along the pcb under or near the main capacitor. If you want to do this mod, you'll need to slide the pcb out, which means removing the 4 screws in the other end and the three in the side, then photo from above.
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I have opened 8 screws from both sides, but the PCB is soooo stuck within the aluminium cabinet that I was not even able to push to slide out..
I even tried to push against something hard but no luck...
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