upgrading a 36v 500w kit to 48v 1000+w

gmihestean

100 mW
Joined
Dec 12, 2015
Messages
38
My current setup: A kit i bought off ebay. http://www.ebay.com/itm/291334105432?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Current Setup:
Battery: 36v 15ah (3 12v 15ah Sla in series )
controller: 36v 500w is printed on the controller. Amps are not listed, china ebay sellers don't knowing anything about their products. Volts X Amps = Watts, so 500w/36v=14amp controller?
motor: 36v 500w
Total bike weight: 80-95 lbs
Rider weight: 135 lbs
max continuous speed: a SLOW 16.0mph

The bike's top speed is much slower then expected. I was thinking i would get at least 20mph. I want to upgrade the battery and controller but still keep the original motor.

Intended use: I would like my upgraded bike to have a 30mph top speed. I would like to use it for 26mile trips. If i cruise at 20-25 mph i believe 20ah should be enough. I am thinking about this configuration:

Battery: 48v 20ah lithium
controller: 48v 1000w 20a or 30a or 40a? or 1440w
motor: 36v 500w

First problem. I can't find a 48v 20a 1000w controller which would give me a true 1000w. They all seem to be 48v 30a or 40a 1000w which doesn't make any sense, or they don't list what the amps are. A 48v 30a controller should be 1440w not 1000w right? 48v X 30A = 1440w. So that controller is only 20a, not 30a, or its actually 1440w, not 1000w. Now i am really confused. Are the kits sold on amazon and ebay actually 1440w but just listed as 1000w kits because the motor is rated to run at 1000w? That means my kit can actually already be 720w or 1000w, its just the seller listed the motor's 500w in the listing. The kits don't list the controllers amps and i haven't gotten a message back from the sellers. I want to upgrade to 48v 1000w based on the 1000w kits reviewed on amazon, because they claim a 30mph top seed. So that means i would need a 48v 30a 1440w controller to achieve a 30mph top speed if the watts are listed incorrectly or if the watts they are referring to are that of what the motor is rated to use without overheating. I am so confused. What 48v controller do i need to achieve a top speed of 30mph but will still give me the option of crusing at lower speeds at less amps to maintain a long range? My motor is rated at 500w, can i run 1440w on it if i am careful or is too easy to burn it out?

Second problem. If the battery i buy has a maximum continuous discharge current of 30A is a 30 amp controller ok? Would the 30 or 40 amp controller damage the battery?
 
I cant' tell for certain, but that's probably teh same motor as the other Yescom 48v kits, so it'll probably do 1000w on a regular basis just fine.

As for the 1000w ratings, why are you so concerned that it be exactly that number? I'm not aware of anything that will limit it exactly to that, unless you have a controller with programmable settings (or do some electronics work to make the shunt feedback tunable), though you could probably use an external device like the Cycle Analyst to do so on the fly if you really wanted to.,


Regarding hte oriiginal kit/controller/speed, did you ever check to see if it has a speed limiter? I ask because 16MPH is about 25km/h, and that is a speed limit for ebikes in some places, IIRC, and I don't see any particular other reason you woulnd't be able to get 20MPH out of what you've got there, even if it took some didstance to get to that speed. Sometiems a "loop" of wire (two single wires that plug together) from the controller can be unplugged to unlimit it, sometiems the wire loop is inside the controller case, and sometimes it's a jumper wire or solder bridge between the ground pad and another (sometimes labeled SL, sometimes other thngs).
 
amberwolf said:
I cant' tell for certain, but that's probably teh same motor as the other Yescom 48v kits, so it'll probably do 1000w on a regular basis just fine.

As for the 1000w ratings, why are you so concerned that it be exactly that number? I'm not aware of anything that will limit it exactly to that, unless you have a controller with programmable settings (or do some electronics work to make the shunt feedback tunable), though you could probably use an external device like the Cycle Analyst to do so on the fly if you really wanted to.,


Regarding hte oriiginal kit/controller/speed, did you ever check to see if it has a speed limiter? I ask because 16MPH is about 25km/h, and that is a speed limit for ebikes in some places, IIRC, and I don't see any particular other reason you woulnd't be able to get 20MPH out of what you've got there, even if it took some didstance to get to that speed. Sometiems a "loop" of wire (two single wires that plug together) from the controller can be unplugged to unlimit it, sometiems the wire loop is inside the controller case, and sometimes it's a jumper wire or solder bridge between the ground pad and another (sometimes labeled SL, sometimes other thngs).


Im not concerned on having exactly 1000w. The only reason i am interested in 1000w is because of the reviews of the 1000w ebike kits on amazon claiming they can get a top speed of 30mph. I don't need more speed then 30mph, and i want to make sure my battery(probably a 48v 20ah) can last 26 miles per charge on a regular basis on the weekends. I was looking to buy a 1000w 20a controller, but couldn't find any and now i realize that's probably not the controller in the 1000w kits and won't get me a 30 mph top speed. They most likely use a 30a controller which means the it runs at 1440w at full throttle.

So now i think i want to get a 48v 30a 1440w controller. The thing is, all the 48v 30a and 40a controllers online are labeled as only 1000w which is confusing.
Here is a 48v 30a controller http://www.elifebike.com/peng/iview.asp?KeyID=dtpic-2012-AX-RAUE.7YSWB
Here is a 48v 40a controller https://bmsbattery.com/ebike-kit/721-s12sn-1000w-40a-torque-simulation-sine-wave-controller-ebike-kit.html

I keep hearing about this Cycle Analyst. If i can monitor and control the amount of amps coming out of my controller that would be ideal. That would mean i could get 48v 40a controller, and only use the maxium 40a on days when i plan to do shorter trips, or just for fun.

Most 48v 20ah batteries have these specifications: Max. discharging current: 50Amp * Max Continuous Discharging Amperage: 30 Amps * Rated Discharging Amperage: 20Amps. Is it safe to use a 40a controller with those specifications?
http://www.ebay.com/itm/191665894415?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I didn't know a speed limiter existed on ebikes until you mentioned it! I will have to look into that.
 
Ok, it's not a 1000W motor. It's a 500W. There is a big difference. With that motor and a 48V battery, you'll get ~25mph top speed. With their 1000W motor, top speed would be ~30mph. This is the kit you should have bought. $30 more would have saved you a lot of trouble and the motor would be rated for 1000W, not 500W. No, the motors are not the same. One is 500W rated at 360rpm at 48V and the other is 1000W rated at 470rpm at 48V. The 1000W motor also weighs a little more.
http://www.ebay.com/itm/48V1000W-26-Rear-Wheel-Electric-Bicycle-Motor-Kit-E-Bike-Cycling-Hub-Conversion-/231520160623
You should have read this first.
https://endless-sphere.com/forums/viewtopic.php?f=3&t=66302
You don't need a new controller. The one you got is capable of using a 48V battery. The problem is it's only rated for 500W. And that doesn't mean its limited to 500W. It's probably a 26A-30A max controller. For more info on this read this.
https://endless-sphere.com/forums/viewtopic.php?f=2&t=74403
The controller you got is more than likely limited to a 63V max because of the caps in it. You can open the end and verify their rating if you want, but I'd bet they're 63V caps.
And here's some more info on the yescomusa kits.
https://endless-sphere.com/forums/viewtopic.php?f=3&t=49638
To know if what you have will work for you, series in a 12V battery pack with your 36V pack and see if it meets your speed requirements.
 
I see a black connector with three wires in the picture. Could that be for a three speed switch?

Maybe it's stuck in slower mode. I don't see a jumper for slow mode in the picture.

I'm sure you can run 48v, which will add about 4 mph to your current speed. But your current speed should be more like 20-22 mph if you have a 7 turn winding motor, 25 if it's a 6 turn like the 1000w kits commonly have. So one possibility is you have a low rpm motor, like a 9 turn. Odd though, if that is the case.
 
That connector next to the battery connector is for PAS. The 3 connectors to the throttle cable are throttle (white), LED battery display, and ignition, which is the red button on the throttle. At least that's what they were on the 3 kits i bought from them.
 
wesnewell said:
Ok, it's not a 1000W motor. It's a 500W. There is a big difference. With that motor and a 48V battery, you'll get ~25mph top speed. With their 1000W motor, top speed would be ~30mph. This is the kit you should have bought. $30 more would have saved you a lot of trouble and the motor would be rated for 1000W, not 500W. No, the motors are not the same. One is 500W rated at 360rpm at 48V and the other is 1000W rated at 470rpm at 48V. The 1000W motor also weighs a little more.
http://www.ebay.com/itm/48V1000W-26-Rear-Wheel-Electric-Bicycle-Motor-Kit-E-Bike-Cycling-Hub-Conversion-/231520160623
You should have read this first.
https://endless-sphere.com/forums/viewtopic.php?f=3&t=66302
You don't need a new controller. The one you got is capable of using a 48V battery. The problem is it's only rated for 500W. And that doesn't mean its limited to 500W. It's probably a 26A-30A max controller. For more info on this read this.
https://endless-sphere.com/forums/viewtopic.php?f=2&t=74403
The controller you got is more than likely limited to a 63V max because of the caps in it. You can open the end and verify their rating if you want, but I'd bet they're 63V caps.
And here's some more info on the yescomusa kits.
https://endless-sphere.com/forums/viewtopic.php?f=3&t=49638
To know if what you have will work for you, series in a 12V battery pack with your 36V pack and see if it meets your speed requirements.

Your right i should have gone with the 48v 1000w kit to begin with. I was thinking i would be satisfied with only the 36v 500w kit at an expected 20mph top speed, boy was i wrong. It's possible that my speedometer was wrong because it was only $10 off amazon with no clear instructions on how close to the rim the magnet and sensor is suppose to be. Ether way im not happy with my top speed, whether its 16mph or truly 20mph at top speed.

I am going to buy a 48v 20ah lithium battery for the higher capacity, lighter weight, and to see if i like the small speed increase. There is no way im putting another 10lb sla battery on my bike, its hard enough to control as a 30 pound battery, let alone a 40 lb one.

If im not happy with the speed after the battery upgrade i could buy just the 1000w wheel motor and a controller rated at 1000w instead of another entire kit right?
 
amberwolf said:
I cant' tell for certain, but that's probably teh same motor as the other Yescom 48v kits, so it'll probably do 1000w on a regular basis just fine.

As for the 1000w ratings, why are you so concerned that it be exactly that number? I'm not aware of anything that will limit it exactly to that, unless you have a controller with programmable settings (or do some electronics work to make the shunt feedback tunable), though you could probably use an external device like the Cycle Analyst to do so on the fly if you really wanted to.,


Regarding hte oriiginal kit/controller/speed, did you ever check to see if it has a speed limiter? I ask because 16MPH is about 25km/h, and that is a speed limit for ebikes in some places, IIRC, and I don't see any particular other reason you woulnd't be able to get 20MPH out of what you've got there, even if it took some didstance to get to that speed. Sometiems a "loop" of wire (two single wires that plug together) from the controller can be unplugged to unlimit it, sometiems the wire loop is inside the controller case, and sometimes it's a jumper wire or solder bridge between the ground pad and another (sometimes labeled SL, sometimes other thngs).

I have been searching for a speed limiter, but i don't think anything matches your description. I took some pictures, maybe you or someone on here can spot a speed limiter, unless its inside the controller. Its possible that my speedometer was wrong since its a cheap $10 one off amazon with no clear instructions on how close to the rim the magnet and sensor is suppose to be.
View attachment 3
IMG_20151213_124616341_Fotor_Fotor.jpg
IMG_20151213_124657516_Fotor_Fotor.jpg
IMG_20151213_125118363_Fotor_Fotor.jpg
 
It's not wired for a 3 speed switch even though it may be capable of it, regen braking, cruise control, etc. You need to set the wheel circumference for the speedo to be correct. And the magnet should be as close as possible without touching the sensor. A 26" wheel with a 1.75" tire should be set to 2035mm. With a 2.3" tire it's 2135mm. It's hard to say what controller you have as they change models from time to time.
 
If your top speed on 36V of 16mph isn't due to a speed limiter on the controller, then to get to 30mph you need to double the voltage, not just go to 48V.
 
It takes about 1000W to maintain 30mph. So that 500W motor isn't really suited for a 30mph constant speed.
 
Ahh, he has no idea whatsoever how fast he's going. Mystery solved.

He's got about 20 mph (22 when the battery is really full), and if he bumps to 48v hell be getting around 27 mph max.

Thanks for clarifying the plug Wes. I'm assuming he's got a 9x7 winding motor, it's the 1000w kits that get the 10x6.

Go for the 48v, and get what you can from the kit. 25 mph cruise is fast enough for most bikes. If you really need 30 mph, then buy another kit later on when you can afford it.

Bear in mind, using sla's, your battery voltage is going to drop very very quickly as you ride. So by the end of the ride, you really are crawling along at 15 mph or so. And, riding really fast with sla's is an excellent way to ruin them in a month or so.

Soooo, brace yourself to spend another thou or so, most of it on a 48v 15 ah lithium battery.
 
wesnewell said:
It takes about 1000W to maintain 30mph. So that 500W motor isn't really suited for a 30mph constant speed.

yes i know i was hoping to cruise most of the distance of my trips at 20-25mph, which would take a little less watts than 1000. Do you think that is doable? I definitely need a way to monitor the amps or watts the controller is putting out though.
 
wesnewell said:
It's not wired for a 3 speed switch even though it may be capable of it, regen braking, cruise control, etc. You need to set the wheel circumference for the speedo to be correct. And the magnet should be as close as possible without touching the sensor. A 26" wheel with a 1.75" tire should be set to 2035mm. With a 2.3" tire it's 2135mm. It's hard to say what controller you have as they change models from time to time.

yes i set the correct circumference on the speedometer and lined up the magnet and sensor correctly, i just don't know how far down the fork the sensor and magnet is suppose to go because it doesn't say in the instructions. I am guessing i need to have it as close as possible to the rim(as high as possible on the fork) while still maintaining a direct line of sight with the spoke and magnet. That way when the wheel turns, the magnet will travel the full circumference of the wheel? I am still able to pedal on my mtb when i have the throttle all the way up, do you think i'm actually going 20+ mph?
 
dogman dan said:
Ahh, he has no idea whatsoever how fast he's going. Mystery solved.

He's got about 20 mph (22 when the battery is really full), and if he bumps to 48v hell be getting around 27 mph max.

Thanks for clarifying the plug Wes. I'm assuming he's got a 9x7 winding motor, it's the 1000w kits that get the 10x6.

Go for the 48v, and get what you can from the kit. 25 mph cruise is fast enough for most bikes. If you really need 30 mph, then buy another kit later on when you can afford it.

Bear in mind, using sla's, your battery voltage is going to drop very very quickly as you ride. So by the end of the ride, you really are crawling along at 15 mph or so. And, riding really fast with sla's is an excellent way to ruin them in a month or so.

Soooo, brace yourself to spend another thou or so, most of it on a 48v 15 ah lithium battery.

I have a 48v 22ah LiFepO4 on order, i should have it by next week :)
 
It doesn't matter where you put the sensor/magnet. It measures revolutions, not the speed the magnet passes the sensor. It then calculates the speed by the circumference of the value you set.
 
I think i figured out the problem with the low speed! I just got a message back from the seller and he says the controller is only about 14amps! No wonder i only get 16mph. If my math is correct, 36v x 14a = 504w maxium output with my current controller. If i had a 25amp controller instead, 36v x 25a = 900w maximum output. So i just need to get 25a or 30a controller to get more speed out of my sla batteries right? I am guessing that with my 48v battery i will get around 20mph top speed with my current controller?
 
wesnewell said:
It doesn't matter where you put the sensor/magnet. It measures revolutions, not the speed the magnet passes the sensor. It then calculates the speed by the circumference of the value you set.

Ah i see, well then my speedometer is setup correctly. Next time i go out i will reset the speedometer and input the circumference again to see if i get the same results, just encase i entered the wrong value in by mistake.
 
It only takes 11.5A for 20mph with the 500W motor. That's ~450W battery power and 350W motor power. So that's not the problem. A new higher max amp controller won't get you any more speed unless your controller is limited in some way. I assumed you've checked to make sure there's nothing dragging on the wheel like hitting the frame, bad bearings, brakes dragging, etc. Both front and rear wheels.
 
Ok,, apparently you did do the speedo setup. I thought you might have just taken it from the box and used it as is.

But 14 amps of 36v should be able to get you to 20 mph easily. The possibility still remains that somehow you got a 6x10 or 6x9 motor, instead of the typical 9x7 winding.

Or, just how big are you? It's quite possible that between weight and and sucky lead batteries, you really only have about 300w of power actually reaching the controller.

What I mean is, take your 14 amps, but then if your 36v battery is sagging to 28v when you roll back the throttle. Then you'd get about 400w for the first 20 feet, then the motor would stop sucking power so hard, and your amps drops to about 10 amps. 10ax 28v is 280w, enough to run about 16 mph.

Chances are a good portion of your problem is the lead. I suspect even if you have a slow motor, you will see 20-25 mph when you get a 48v lifepo4. The lifepo4 will hold a higher voltage much farther down the road than the lead.
 
wesnewell said:
It only takes 11.5A for 20mph with the 500W motor. That's ~450W battery power and 350W motor power. So that's not the problem. A new higher max amp controller won't get you any more speed unless your controller is limited in some way. I assumed you've checked to make sure there's nothing dragging on the wheel like hitting the frame, bad bearings, brakes dragging, etc. Both front and rear wheels.

Wow i didn't think it only took 11.5A, then yeah something is wrong. The wheels spin freely and there is nothing dragging on the wheels, however i did have a hard time installing the rear hub motor in the rear dropouts and that wheel is off center. I had to disassemble the hall connector to change the washers on the cassette/gears side of the wheel because the gears were rubbing against the frame, the wheel couldn't even move the first time i installed it. I found that using one flat washer from the kit was not enough. By using two flat washers it allowed the chain to use the last gear, but as a side effect the two washers moved the wheel off center, so the wheel is a little closer to the side without the gears by a distance of the two flat washers. The washers are kind of thick and i probably could have gotten away with using 1 washer from the kit, and another washer with half the thickness, which would have allowed me to add a washer on the other side and make the wheel less off center, but i didn't have any washers outside the kit so i just left the wheel with the two washers from the kit on the gears side. With the two washers on the gears side i couldn't fit any washers on the other side of the wheel to make it centered. I tried to add at least 1 washer but the frame wouldn't budge and i was scared i was going to damage something with that amount of force. Could the wheel being off center be the problem? The wheel spins freely and i never thought much about it.


Your saying a controller with a higher maximum amps, which means more watts, wont get me more speed??
 
dogman dan said:
Ok,, apparently you did do the speedo setup. I thought you might have just taken it from the box and used it as is.

But 14 amps of 36v should be able to get you to 20 mph easily. The possibility still remains that somehow you got a 6x10 or 6x9 motor, instead of the typical 9x7 winding.

Or, just how big are you? It's quite possible that between weight and and sucky lead batteries, you really only have about 300w of power actually reaching the controller.

What I mean is, take your 14 amps, but then if your 36v battery is sagging to 28v when you roll back the throttle. Then you'd get about 400w for the first 20 feet, then the motor would stop sucking power so hard, and your amps drops to about 10 amps. 10ax 28v is 280w, enough to run about 16 mph.

Chances are a good portion of your problem is the lead. I suspect even if you have a slow motor, you will see 20-25 mph when you get a 48v lifepo4. The lifepo4 will hold a higher voltage much farther down the road than the lead.

Im only 135 pounds so i don't think its the total weight. I will find out next week if its the SLAs when my 48v 22ah lifepo4 arrives. The battery connector on my 36v 500w controller has a fuse, would would i still be able to use my 48v on it?
 
I missed he was using lead. If it's sagging to 30V then ~16 mph is all he'd get. The fuse works on amps. Going to 48V should not affect it.
 
update 12/17/2015

I managed to get my wheel perfectly centered by using only one washer on each side, in between the frame and wheel. That is a huge improvement from being two washers off center, but its a trade off because i can only use the highest gear/smallest cog in the rear and i can't change gears because the rear rack's mounting nut is in the way. My maximum speed on flat ground is still only around 16.6 mph.

I was too embarrassed to tell you guys, but the first time i rode my converted ebike, my rear rack which had my 30 pound lead acid battery and controller fell off the bike and hit the pavement. All the connectors ether disconnected, or the locks that held the cables in place broke and the cables separated. The problem was i didn't tighten these 2 screws on my rear rack tight enough, and the screws came loose and fell out after riding my bike for about half an hour, and then my rear rack flew backwards because the rack was still attached to the bike at the bottom two screws. I had to get back home so i checked the batteries and controller but nothing seemed damaged except that all the cables were disconnected. I reconnected all the cables and everything seemed to work fine. Luckily i had some 300 pound paracord with me, so i was able to tie the top of my rack to my seat post. When i got home i immediately tested the voltage of each battery and they were all the same at around 12.3v. I connected the battery in series again and charged it to 40.1 volts and they dropped down to 39.3. I tested each battery again and they were all the same at 13.1. The battery seems fine, i suspect that my controller or cables might have been damaged when rear rack and battery tore all the connections apart as it hit the ground. None of the cables look physically damaged aside from plastic locks the held the connectors together broke, but maybe something came loose inside the controller? I don't know. The top speed did seem faster before my battery and controller fell, but i didn't have a speedometer at the time to know exactly what top speeds i was hitting so i'm not exactly sure if the top seed was actually faster. It may have been that my bike seemed faster because it was my first time riding it with a motor.

My new lithium battery arrives tomorrow so i will give you guys an update if that makes a difference in the top speed.
 
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