Over volt 48v hub motor?

[aa-4123]

I am new here and this is my first post. I am thinking about getting an e bike soon. I have a mountain bike with 26" wheels and 6 speed freewheel. I found a kit which is a 48v 1000w hub motor mounted to a 26" rear wheel with 6 speed freewheel. It all looks good and easy to install. It says it reaches top speed around 50km/h. I want to go faster. It also comes with a 48v 1000w controller. Can I use a 72v 20ah battery that discharges at maximum 40ah and buy a 72v 1500w controller. I understand that extra heat will be made. If i drilled holes on the side panel would it provide sufficient cooling. What speeds will i get to on a flat after everything is finished?

 

[dogman dan]

Sure, if you battery can take it no problem. BTW, 1500w is still not that much for those motors. 2000w is likely to be OK, and if you keep the ride short (5-8 miles) 3000w will work.

For 1500w, 72v 20 amps I have a controller like that, and like it a lot. Slow off the line with only 1500w, but eventually some nice speed.

I also 3000w have 72v 40 amps, Real nice ride, but makes a lot of heat in the motor pretty quick. I ride that controller a lot in winter, when heat build up is less than in 105f weather. About 5 mph faster than the 1500w, and a LOT faster off the line.

I keep meaning to try 72v 30 amps, but never got the controller programming software to load on my computer and work.

 

[wesnewell]

Assuming it's the 48V 1000W version of this.
http://www.ebay.com/itm/Rear-Wheel-Electric-Bicycle-Conversion-Kit-24V-36V-48V-250W-500W-700W-800W-1000W-/290754592384
Running 88.8V with a cheap 72V 40A controller I see speeds of about 70kph. Can cruise at 55kph until battery is drained without over heating the motor or controller. Should get at least 65kph top speed with 72V pack.

 

[dnmun]

you might be able to upgrade your controller from 48V to 72V by changing the input capacitors and input power resistor only. you can read the part number off the mosfets to see if they will handle the 89V also.

 

[aa-4123]

Thanks for the replies. I just realized I would need a new throttle. any recommendations? Also I can't solder anything on a PCB.

 

[aa-4123]

Assuming it's the 48V 1000W version of this.
http://www.ebay.com/itm/Rear-Wheel-Electric-Bicycle-Conversion-Kit-24V-36V-48V-250W-500W-700W-800W-1000W-/290754592384
Running 88.8V with a cheap 72V 40A controller I see speeds of about 70kph. Can cruise at 55kph until battery is drained without over heating the motor or controller. Should get at least 65kph top speed with 72V pack.

Yes it is that one but from a different seller.

 

[aa-4123]

Sure, if you battery can take it no problem. BTW, 1500w is still not that much for those motors. 2000w is likely to be OK, and if you keep the ride short (5-8 miles) 3000w will work.

For 1500w, 72v 20 amps I have a controller like that, and like it a lot. Slow off the line with only 1500w, but eventually some nice speed.

I also 3000w have 72v 40 amps, Real nice ride, but makes a lot of heat in the motor pretty quick. I ride that controller a lot in winter, when heat build up is less than in 105f weather. About 5 mph faster than the 1500w, and a LOT faster off the line.

I keep meaning to try 72v 30 amps, but never got the controller programming software to load on my computer and work.

For 1500w, how slow is 'slow of the line'? Does it at least accelerate faster than cars? What is your top speeds on 72v 1500w. I usually ride 2.5 miles each way but will sometimes need to go 7 miles one way.

 

[knighty]

get a 72v 1500watt hua tong controller and it'll kick you in the pants off the line

I know, I've got the same wheel, connected up to a hua tong, 72v10ah battery

searh hua tong on here/ebay/alibaba etc... there's loads of people selling the same thing

 

[wesnewell]

FYI, a 72V 1500W controller doesn't mean the max wattage is 1500W. It means that is the max rating for running it 24/7. My 72V 1500W controller has a max amp rating of 40A. A typical 24s 72V lifepo4 pack is 76V nominal and fully charged will be ~86V. VA=W, so 40*86=3440W.

 

[aa-4123]

FYI, a 72V 1500W controller doesn't mean the max wattage is 1500W. It means that is the max rating for running it 24/7. My 72V 1500W controller has a max amp rating of 40A. A typical 24s 72V lifepo4 pack is 76V nominal and fully charged will be ~86V. VA=W, so 40*86=3440W.

So a full throttle on a fully charged battery will pull more than 3000w from a stop. Is there a chance that the motor will overheat because of continuous stop/start like in city traffic.

 

[dogman dan]

I tend to speak in terms of controller amperage, rather than "rated wattage" on controllers. Some vendors rate a 72v 40 amps controller 1500w, others 3000. No real consistency, just like battery vendors that some sell nominal voltage, others spec max charge voltage.

For the case of 72v 40 amps controllers running these generic 9c, golden, conhis, muxus, etc type motors.... To be specific, I mean the 28mm rotors.

Can you melt it? Hell yeah!!! Must it melt? Hell no!! On a dirt trail, or a racetrack, or practicing for racing, I've melted several, and on other occasions gotten them really crazy hot.

Riding "normally" in traffic, I doubt you'd ever melt one in 10 miles. But I find longer rides than 10 miles are often the cause of melt downs. It just all depends on how much throttle you are using on those starts. Go easy on the throttle, pull 2000w max, and you can easily keep your cool. Make every start a wide open throttle drag race start, and you will heat er up. Weather has an effect too, I don't try to run hard in the hottest part of summer. I run a 1500w controller then.

These motors are not made for, nor rated for 3000w, But you can get away with 3000 w for awhile. 8)

After you melt a few motors, you do learn to have a thermometer inside them if you run them hard. Then you know when to stop or at least back off. Drilling lots of big vent holes in the side covers is also proven to help. There is about 10,000 pages of discussion of both motor cooling and temp monitoring here on ES.

 

[wineboyrider]

Hey Dogman you need a plug in CA that way you can control your controller's wattage....LOL.

 

[wesnewell]

FYI, a 72V 1500W controller doesn't mean the max wattage is 1500W. It means that is the max rating for running it 24/7. My 72V 1500W controller has a max amp rating of 40A. A typical 24s 72V lifepo4 pack is 76V nominal and fully charged will be ~86V. VA=W, so 40*86=3440W.

So a full throttle on a fully charged battery will pull more than 3000w from a stop. Is there a chance that the motor will overheat because of continuous stop/start like in city traffic.

You'll never pull max amps/watts unless put the bike up against a wall and go full throttle. In normal riding you'll probably never see more than 90% of max, and just for a second or two when you take off. It will quickly drop off once you get moving, even uphill unless it's a steep mountain. Keep speed to under 35mph and you can run it all day long in normal terrain with steep short hills and longer ones with a mild slope.
Please go to the User Control Panel, select Profile, and then enter your city, state/province, and country into the Location field (country minimum) and save it. This will help people help you. Example: Wylie, TX, USA. Without knowing what country you are in it's hard to make any recommendations. Thank you.

 

[tatt]

I am new here too and i am doing the same setup with my bike, but the motor is making clicking noise and the bike feels a lot slower @80v than it did @ 54v. Maybe in connecting some wrong . The new controller is a 72v china hua tong. Can someone help me please.

 

[999zip999]

Yes you will have problem melting your motor melting your.wires and blowing your battery. We all have. It's a learning curve. All thing must match and kept under the limit. Plus rc lipo. Arn't toys and can make fire. So if not done right it will cost a lot of money.
So no cheap batteries a C.A. and keep the amps down to start. Meaning it's not all gravy. So read up.

 

[wesnewell]

I am new here too and i am doing the same setup with my bike, but the motor is making clicking noise and the bike feels a lot slower @80v than it did @ 54v. Maybe in connecting some wrong . The new controller is a 72v china hua tong. Can someone help me please.

What motor do you have? You need to reverse the green and yellow phase and hall wires if it's a yescomusa (GM) motor.

 

[heavymetalthunder]

Full throttle starts can really pull a lot of amps. I'm running a 1000w 48v set up and using my watt meter at full throttle start the watt meter shows my power draw of 1400 watts of power. If you are starting to experiment with different setups, I would suggest you get a watt meter, they are very handy and might prevent you from frying something.

 

[tatt]

Thanks its working properly now. i am seeing speeds of well over 40 mph. i did what you said switch the green and yellow wires on the hall and Phase. and thanks for the setup idea, i copy your exact specs except for i have a 15ah battery.

 

[999zip999]

Put your hand on the motor as a temp sensor to check, in the begin and monator temp. to be on the safe side of melt. Just to be safe side. Just check it to keep ahead of trouble. Good job and good luck.

 

[ebike11]

Hows most peoples torque with that motor and Hua Tong 72V 40A controller?

 

[wesnewell]

The yescomusa 1000W motor will take a lot of punishment. I got mine Feb 2010 and ran it until June on 14s lipo. That when I got the 72V 40A controller and ran it on 18s for a year but did make some 24s runs after I first got the new controller. Been running it oin24s since June of 2012. Got over 10,000 miles total on it without a problem. 6000 of those at 24s. But I don't push it either. Most of my rides are at 12mph pedaling along with it for exercise. Been retired 12 years now. The few times I've gone 10 miles at 30mph I never had a problem. Someone lighter than my 270 lbs should be able to do 35mph all day long without a problem.

 

[dogman dan]

With the right balance of the bike, you can wheelie with 3000w. I would build it to not wheelie though.

It will out run cars till they overtake you at more than 40 mph. Comparable to a smaller motorcycle for speed off the line.

Blows away bikes with a stock china girl gas motor completely. Competitive with those with good carbs and exhaust.

Very fun. But despite Wes claiming they will last forever, I guarantee you I could melt one in 40 min. Just takes real steep trail riding, or a race track with lots of corners. The race track can wear out tires in 40 min too.

Hard to push one that hard on the street though. Typically you are either there, or out of battery before they melt. The real problem is cops, or cars that think you are going 15 mph, rather than 40 mph.

Push them to 4000w, and they will melt down for sure. Some do that anyway, but they have to be very careful to get away with it.