36v to 72v HELP?

[bobby3legs]

I have a 680w brushless motor and would like to put it on a chopper. I have my bike now running on 36v lifepo4 and i have another battery sitting. i was wondering how to use what i have as far as motor and batteries and turn the chopper into a 72v machine. is this possible? and if it is what kind of controller do i need and do i have to change the throttle? both batteries have bms do i have to reconfigure? Before i buy the chopper i would really appreciate any help

 

[mwkeefer]

Bobby,

You either need to upgrade the controller you have already if it is an Infineon 6-18 FET type your set... just order some IRFB4110s and 3 new 100v caps and you have a 100v 30A controller (actually it's 100A but requires soldering the shunt inside the controller) - this is all covered, search the forum for "Infineon Controller Technical" and so on for more details.

The other option would be to contact one of the forum guys who build these up from scratch like Methods... They usually have these floating around ready to ship (finished controllers or parts)... I think methods website is www.deviantmethods.com but I could be mistaken.

20" on a Chopper @ 72v nominal = not bad but, LiFePo4 will sag under heavy current draw (most 10AH packs can't discharge more than 20A continuous or they drop a ton of voltage.). What speed are you trying to acheive in the end?

Converting from Delta to Wye would buy you much more top end but you could be happy with nothing more than reprogramming your controller for say... 38A (it should be factory limited to 22) that will give you a nice punch, you can also set up to 120% advance on the motor speed at WOT (Parameter Designer).

You might be better off to leave the 22A factory limit in place... also leave the controller alone - no hardware upgrades just reprogram it a bit... Parallel the LiFePo4 packs into 36v 20AH (assuming 10AH packs) which can handle 38A discharge when switched into Wye mode...

What are your speed goals?

Range?

-Mike

 

[317537]

Almost everything and anything is possible. That's a big leap in volts there. Are you sure you want to go that high?

Issues.

Motor windings. Can they take 80+ volts on the high end of charge.
Controller. Is your controller going to be able to do this without a major overhaul to the fet bridge.
Batteries should be fine in series with little changes.
Throttle is fine as long as controller is in specs.
Bike, will it be strong enough to handle a 72v supply and the speeds you may encounter?

You know a good 60v upgrade on a smaller radius wheel is quite sufficient in Ebike terms. You will really be laying the cash out thick on performance parts to keep a bicycle working and safe at 72v. Like you may even have to replce half the chopper before you feel it's up to standard. So in chopper design buy heavy duty from the start up.

Ok some specifics could help. Motor type and brand. EG hub, RC, brushed, brushless.

Controller brand and model. some pics of the internals helps quite a bit and what part no. fets are installed.

Cheers

 

[bobby3legs]

http://ibikedb.net/bikes/14329-schwinn-stingray-spoiler <----- this is a pic of the bike i want to put the motor on

 

[bobby3legs]

i want to reach at least 30 . these bikes can handle it. there are gas motors put on these bikes with over 50cc

 

[bobby3legs]

my battery is 20ahr

 

[bobby3legs]

Can someone tell me exactley what controller i need and where the best place to get

 

[dnmun]

why not just say which motor/controller? 680W is no clue.

to upgrade to 72V you need to certify that the FETs will handle the 88V of the 72Vlifepo4 pack.

you have to replace the input power resistor to protect the voltage regulator and you need to replace the 63V caps with 100V caps like i did with this controller:

http://endless-sphere.com/forums/viewtopic.php?f=2&t=10222

i have the caps and resistors for sale, 30 cents for the caps and 11 cents for the 300 ohm 2W resistors.

 

[bobby3legs]

why not just say which motor/controller? 680W is no clue.

to upgrade to 72V you need to certify that the FETs will handle the 88V of the 72Vlifepo4 pack.

you have to replace the input power resistor to protect the voltage regulator and you need to replace the 63V caps with 100V caps like i did with this controller:

viewtopic.php?f=2&t=10222

i have the caps and resistors for sale, 30 cents for the caps and 11 cents for the 300 ohm 2W resistors

i have the pegasus 680w motor. with a home made controller. what do you mean on fets. i will need a new controller i'm sure

 

[amberwolf]

And since there are now three threads about this same project, here's links to the other two so anyone helping in one thread can also see the info in the other two and maybe help the OP find a solution in one of the threads, at least.

http://www.endless-sphere.com/forums/viewtopic.php?f=1&t=13385
http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=13386

 

[bobby3legs]

yae i'm a newbie and kepted reposting before i figure out t reply.

 

[E-BikeKit.com]

Deleted. Thank you to all at ES.

 

[Drunkskunk]

Thats a nice bike, should make a great build

As for the motor.. 680 watts, Thats an odd number for the company to come up with. Usualy companies that do that are giving you the max wattage, based on what the controller will allow, and rounded up. a 36v (42peak) LifePo4 battery with a 16 amp controller would have a peak wattage of 672 watts.

Most reputable companies rate there motor based on its constant load, not its peak, but there is no actual guideline. very likely that makes it a 500 watt motor by the conventional measurments we use here. The other hint about it being a 500 watt motor is the size of the controller they offer. its tiny. 6 fetts at best, which makes it appropriate for a 500 watt motor at 36 volts.



So what does all that mean? Maybe good news for you, and heres why:
A reputable company wouldn't go through the expense of buying the millions of dollars worth of manufacturing facilities and equipment, then make grandious claims that are only true by a technicality.
That would be like Ford claiming all it's current and past cars actualy run on a renewable resource and are powered by the sun. Technicly true, oil is renewable if we give the earth afew hundred million years, and the original energy in the oil came from sunlight photosynthisized by the plants before they died but thats a stretch so long Ford wouldn't dare make it.

So that means Pheonix is likely a reseller, buying there motors from someplace else, then developing them into a kit. There aren't that many manufacturers of Brushless motors, as the equipment for them is extreamly expensive right now, and the technology is still so new. So the motor is likely from one of the major manufacturers and therefore likely to exhibit similar characteristics.
In otherwords, yeah, the motor will very likely take 72 volts without issue.
The only problem you might run into isif the motor was speed Wound for 36 volts. if thats the case, it will be an Amp hog at 72 volts

Whats it's top speed right now?

As for controllers, i would go with a 20 Amp 72V Infirion. that would give you 2 horsepower peak, enough to do a burnout with your weight off the bike.

 

[bobby3legs]

i get 21mph and did i mention hall effect

 

[Drunkskunk]

21mph at 36v is roughly equivolent to the speed a 9C 9X7 can make. I bet you'll do 35mph with double the voltage. Wind resistance increases will be the key.

 

[Drunkskunk]

And to help consolidate these threads, I'll post here instead of the other.

The last place you're going to want a motor on that bike is the front wheel for a couple reasons.

• All your body weight is in the back. All the weight is on the back tire. if you have your power being delivered through the front, its going to lose traction easily. Thats cool if your standing still and want to spin the tire, but very uncool if you're going through a corner and start to lose grip.with power on the front wheel, once you start to lose grip, the tire will spin, all controll will be lost, and gravity takes over. 9mXs^2 is faster than you can react. You will have a close up look at the pavement.
  
  Its a chopper, the dynamics of the way the front wheel works is far diffrent than a normal wheel, meaning it leans way over onto its sidewall in the turns, and that isn't good for traction.
  
  You're pumping more than twice the power, and possably 4 to 6 times the power through this motor as it was rated for. The dropouts will likely take it, but the rest of that suspension system was ment to handle a grand total of Zero power through it. Not to mention all that power way out front of the weight of the bike, see point 1.

 

[SimSamurai]

Hi guys, I had to chime in here. I just discovered this thread because I too just bought the same bike and want to make it an e-bike with a high power brushless motor.

In Bostonian terms I want it to be "wicked fast"! Alot of folks have converted the Schwinn Stingray and Spoilers to the 80cc (66cc really) 2 stoke motors and can get 100mpg with speeds of up to 45mph but if I can hit that with an e-bike conversion I'd much rather go that route as well! --not to mention three cheers for lower carbon emisson! I also want something that can do at least 20 miles on a charge ...basically enough to get me to work and back (in the bike lane of course) If I can risk getting a speeding ticket...even better!

Ok, enough...just check out these two YouTube videos...great stuff! (I think the motor would be better in the rear too though unless you have a fatter tire?)

E-Bike Kit 36v/500w system - 72v conversion - modified controller - 2 36v 10amp batteries in series - avg speed 35mph with 210lb rider (on Schwinn Stingray)
http://www.youtube.com/watch?v=kChARK_blPE

Motorized Chopper with a 7 gear conversion...sick! (on Schwinn Stingray)
http://www.youtube.com/watch?v=yDeip37nNKQ

My thoughts are this... Keep the pedaling functionality, add a 7 speed rear, add phatter front tire perhaps same size as rear, and keep motor in the front? Thoughts?

 

[willmelee4food]

Hey guys,

I have the same Schwinn Spoiler and I am also in the process of an extensive build. Heres a list of the basics:

You can follow my progress on visforvoltage.com, search for "Spoiled Spoiler" http://visforvoltage.org/vehicle/spoiled-spoiler/7417

Motors: 2 Anada BLDC Hub Motors laced to 4.25" X 20" wheels. These are the stock hub motors from the smaller electric Schwinn Stingray. Originally rated at 250w at 24v.

Controllers: 2, 350w, 48v, 15a brushless hooked to 1 48v thumb throttle with LEDs. Shunt modded to 25-30a output.

Custom Features: Custom Milled Triple Clamps for extra wide 4.25" front hub motor, 3 custom milled disc brake adapters, dual 203mm rotor hydraulic brakes up front, single 180mm on rear. Cheese ball plastic chrome "v-twin" stock battery case from donor bike for housing controllers, keyswitch, diagnostic LEDS, XLR charge port, ect.... Fiberglass gas tank chopped and cut to hold Watts up meter , speakers, amp volume control and ipod dock. Saddlebags for hiding SLA battery pack.

I am sure alot of you out there want to see my triple clamps, well..... so do I! I have the materials and design but milling them out at work during my 15 min breaks is just taking forever. As soon as it is done, fitted and looking sexy, I will post all my pics.

If anyone is interested in purchasing a set of the custom milled triple clamps, please contact me @ willmelee4food@hotmail.com. I have quotes from a local CNC shop but minumum order is for 10 complete sets.