24 volt 36 volt AND 48 volt

[mountain biker]

okay.....looking at stats on some of these motors...I see the basic thing they are selling. looks like a 200 slow wind high torque or a speed wind 300 rpm lower torque but higher speed. for the same motor....

question....
I was looking at some of these stats and it seems if you get a 1000 watt motor...and you only put in 24 volts around 10 amps... you are getting the same output as if you were to buy the same motor in a 250 watt version. so does this mean..i can buy a 1000 watt motor that is rated at 48 volts 22 amps and just put 24 volts and 11 amps roughly....what happens? I noticed the rpm list on some of the data sheets seems. seems lower...

so what happens if we get ridicuolous and say take a 48 volt 1000 watt motor and run 24 volts 40 amps roughly? is this possible? most of these motors are rated for 30 or so amps.... I understand the wire would be as thick as a hotdog to hold the amps. but

if you guys could give me some motor specicifics is what I am searching for......

 

[d8veh]

The volts directly affect the speed of a motor, so a 48v one will go at half the max speed at 24v. At 10A, it will be completely gutless. It'll hardly have enough torque to get itself up the road, let alone with you on it. Bear in mind that 250w motors are rated at 250W, but run up to a max of about 600w from the battery with a 250w controller. They nearly all run happily at 900w.

The current affects the torque more or less directly. If you put 24v 40A through a 1000w motor, it will have the same torque as 48v 20A, but will go at half the speed. The motor would probably be able to take 40A provided that it has good phase wires, but you'd need to find a 40A controller and battery. You'd also need very good connectors on the phase wires.

 

[wesnewell]

Welcome to ES****Do this before your first post or now (it's retroactive)*****
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[dogman dan]

What exactly do you want to do? In general you'd be better off to run 48v, and lower amps. There are lots of kits out there with multiple "speed" choices, so you can dial in a lower power, lower speed mode when you want it.

I don't really think there will be noticeably more torque with 24v if total wattage is the same. More torque for sure if you make the rim smaller. So if you want torque, look to 20" rims.

If you want very slow speeds, then perhaps a mid drive might work best for you.

 

[mountain biker]

these multiple speed kit choices would be cool. too know...knew to researching all this stuff...looks like bms is the onlywebsite I have found beside some alibaba.com sites on choices of motors and controllers...I do like the format of bms battery, it seems easy to shop around on. however I can tell from time to time some language barriers...like heading will have different rpm than info stated on detail side. even when you click the speed choice column 201 rpm or 301 rpm...but all and all looks cool. and they do seem to put out a price...so much competition on this ebike stuff a lot of these sites don't really put down a price, it requires an email...

you know though I have never really ever seen data on a motor..lets say the double speed motor...it has a 24 36 and 48 volt. or any motor is cool..

but you never get to see the stats of different voltages and amps other than what they are providing as their pr stuff...
the only thing I have seen is the magic pie series that has different voltages and watts you can dial in....

but does the cycle analist do that for you just use exsisting controller and then run cycle analysit after that and this can controller what kind of power your putting to the motor?

 

[dogman dan]

Well, I can't point you to the company where I work, selling motor kits with multiple power options. I'll give you a hint though, it's not in China, nor is it cheap.

We have a hard time pointing you to the best vendor for you, when we have no clue what continent you live on. You could be in Australia or Austria or Austin TX.

You might be very well served by going to the website of the owner of this forum. The guy who keeps it free of disgusting ads. Justin has put up just about the best informational pages as anybody, including a simulator that allows you to look at some popular motors at various voltages, as well as all the other variables.



http://www.ebikes.ca/learn/intro-to-ebikes.html

 

[dnmun]

Well, I can't point you to the company where I work, selling motor kits with multiple power options. I'll give you a hint though, it's not in China, nor is it cheap.

We have a hard time pointing you to the best vendor for you, when we have no clue what continent you live on. You could be in Australia or Austria or Austin TX.

You might be very well served by going to the website of the owner of this forum. The guy who keeps it free of disgusting ads. Justin has put up just about the best informational pages as anybody, including a simulator that allows you to look at some popular motors at various voltages, as well as all the other variables.



http://www.ebikes.ca/learn/intro-to-ebikes.html

dogman consults online for jason who runs the ebikekit.com web.site out of eastern pennsylvania. forgotten their exact website handle but they have monthly special deals too but jason has gotta be one of the most responsive sellers of ebikes. i think almost all of us have bot 9C motors from him back in the day

 

[mat h physics]

The purpose of using AC power in transmission is to ramp voltage up for lower power losses. More power is lost due to amps than volts. This was a real problem for Edison when he started his power company, as the furthest customers were getting dramatic power loss. Think it has something to do w/ creation of heat and magnetic fields.
[youtube]http://youtu.be/oGs1GlgrmbI[/youtube]

 

[mountain biker]

cool mat. I read some of your other postings on this thing and I appreciate your input. and to the California bike consultant didn't mean to put you in a sticky situation here. just asking about different kits in general, I can see you being a dealer would put you in a particular rough spot, I would like American made. or atleast American representation. I can have up to 750 watt motor here in america but in most of Europe its like 250 right? if you got any info on a particular motor that is ran on different voltages like 24 36 or 48 would be cool. different kits with different voltages...

I guesse I am looking for any data that anyone has collected on high amp to volt ratio. 24 volt 30 amps for example. I can find charts for some motors for the double speed motor (which I don't sell or can even spell their company name right) for only 36 volt... I did read some stuff today that suggested the higher amps you use increases battery drain. saying that higher voltage lower amp is better for effecience on motor...but surely something must give higher torque somewhere at the expense of added amps. then less amps being used as speed increases....I don't know..im fishing...

I guesse I am just trying to see the difference say for a magicpie that is 24 36 48 for example what different ranges and speeds they can get...its interesting.
or any motor that can be ran on 24 36 or 48 volts.

 

[dogman dan]

Well, in the end it's all just about watts. The nice thing about thinking in watts is 500w of 24v is exactly the same as 500w of 36v,,,, before you send it down a wire that is.

On an ebike, how long is your longest wire? 3-4 feet in most cases, so really it doesn't matter too much whether you run 500w of 24v, or 500w of 36v. Not enough wire to make huge differences on a typical street legal bike. And close enough, the torque you get from 500w is the torque you get from 500w, unless you change gearing or something.

BTW, watts is amps times volts. So in general, if using the same controller and motor, then increasing the volts does indeed change the watts. That is where you tend to get the benefit of running 48v. If the controller remains the same, for example 22 amps, then 24v is 500w ish, 36v is 750w, and 48v is around 1000w. For most of us here on ES, more watts is better.

Also, the motors top speed increases with volts. So 24v might be 15 mph, 36v around 23, and 48v around 28 mph, for bikes with 26" wheels.

Re the marketing thing. You didn't put me in a spot. But I'm not allowed to just spam the site in every post with links to my employer. If it was allowed, the link would be in my signature. I thought about changing my ES name from dogman, to E bikekit dan. But I needed to keep dogman because of the post history. Besides, you never work for one place forever. I did reveal my real first name here recently, so you'd get the idea when you see some dude named Dan on the E bikekit website.

 

[Ykick]

One little thing to throw out there for consumption - all of this talk about motor speed on certain voltages "assumes" a controller outputting full 100% speed. That's the default from most of the mainstream sources for this gear.

But with some modifications and programming it's easy enough to run a very high pack voltage by turning the controller speed down so that the motor only spins at lower RPMs comparable to it's rated voltage.

It's not that big of deal to overspeed DD (direct drive) motors since they can tolerate much higher voltages than their ratings but for smaller geared motors designed for top speeds of 36V they should not be expected to last long if/when oversped.

For example, I've gotta small geared hub rated 36V but I can safely run it on a 67V (59V) battery pack because speed is turned down to 50-70% in the controller parameters.

I like my 67V battery pack energy density (Wh) and physical size. Plus, it's the same pack I use 100% speed on DD motors so with a little programming it can also safely run my 36V geared mini-motors. Food for thought....

 

[mountain biker]

first off I like where this is going. appreciate all feedback....
so with your 67 volt setup...what is set up if I may ask? so your using the higher voltage battery to help you increase range and the trick is trying to limit your amps consumed by load by peddling. what kind of battery do you have and what is ah. so lets says someone has a 36 volt 10ah=360wh.(basic assumption 100 percent discharge. I guesse we should only save 30 percent of lifepo or 60 percent of lead acid to recharge.) your 76 volt say 10 wh would be 760 wh...but your 36 volt engine is running at what amp max setting? your 36 volt motor consumes what level of wh. say on a straight stretch. thank you for including the higher voltages didn't mean to exclude anyone. but I guesse the advantage of higher voltage battery but current and voltage limited by controller to around factory spec is range then? say 60 volt battery with 5 amphour as compared to say 30 volt battery with 10 amphour.
both have same wh (and please subsititue 60 for 67 or 30 for 36 or whatever. just seems like easier math) what is advantage and how do you run it...are you banking on heavy peddling at start up? I like where this is going.

 

[Ykick]

My pack is a custom 16S (16 cells in series) assembled from 4qty Turnigy 4S 20C 5Ah Hardcase bricks. For low power bikes it's generally a 16S1P (16 series, 1 parallel) configuration but it's easy enough to parallel more cells/groups for higher power bikes and/or more range. Which would be called 16S2P or 16S3P, etc.

As you noted battery pack voltages cover a wide range. In this case 16 Lipo cells in series usually stated as 59.2V which is the nominal voltage rating of these cells. 3.7V x 16S = 59.2. However, being a dumbass layman I usually see about 67V HOC (hot off the charger) or 4.2V x 16S = 67.2V and I hardly ever see anything resembling 59V except for under load.

It's one of those things you'll get used to when people toss around battery pack voltages. Generally speaking, a 36V LifePo4 battery will often measure around 42V HOC. As you've observed there's a wide range of voltages which can be called 24, 36, 48, 60 but can be quite different when actually measured.

As far as my preference of 16S RC Lipo it's merely a friendly form factor and connection of 4qty 4S bricks assembled into a compact sub 5lb package. As mentioned in this thread, it's really about Wh anyway and higher voltages allow you to carry more Wh than lower voltage given the same P configuration. Another benefit is lower wiring losses for any battery power runs.

In my situation, DD bikes handle 100% speed on 67V (59.2V) just fine but the little geared mini-motors can't. With a controller modded for higher volts (don't try anything over 62V on stock 48V controllers) and custom programming to reduce speed and limit battery current to rated levels for my motor, the same pack can be used across all my motor/platform configurations.

Of course, this leads us into the RC Lipo debate. Can you get the requisite experience without burning your house down? Some folks have RC background and will be ahead of the task. Others like me, may need years of small baby steps to arrive at a reasonably safe BMS protected RC Lipo battery pack.

Here's a pick of one of my 16S1P packs described above:

 

[dilkes]

Of course, this leads us into the RC Lipo debate. Can you get the requisite experience without burning your house down? Some folks have RC background and will be ahead of the task. Others like me, may need years of small baby steps to arrive at a reasonably safe BMS protected RC Lipo battery pack.

What BMS do you use with that 16S LiPo pack? I am building one as well. Do you have a pointer to where the BMS can be purchased?

 

[Ykick]

Of course, this leads us into the RC Lipo debate. Can you get the requisite experience without burning your house down? Some folks have RC background and will be ahead of the task. Others like me, may need years of small baby steps to arrive at a reasonably safe BMS protected RC Lipo battery pack.

What BMS do you use with that 16S LiPo pack? I am building one as well. Do you have a pointer to where the BMS can be purchased?

I use the HCX-D140 for my 15A bikes and HCX-D167 for my 35A bikes found here:

http://www.bestechpower.com/592v16spcmbmspcbforli-ionli-polymerbatterypack/

User dnum has handled group buys before if you can catch one of those or I've also bought directly from the company observing 2 MOQ (minimum order quanity).

2 D140's cost me about $85 shipped and 2 D167's were about $110, IIRC?

Good boards, I've screwed a few of 'em up but a good price for all the components, performance and peace of mind. But you still need to carefully check for proper HVC/LVC protection(s) and any shorted channel balance circuits, etc., before considering it a done deal.

 

[mat h physics]

Really like that setup Ykick, contemplating DD or GH for a while. Leaning GH, due to high weight and only really wanting it for steep hills. As for BMS, is this ES common knowledge? I posted this when reading a book on large BMS, http://endless-sphere.com/forums/viewtopic.php?f=14&t=55341&sid=9119cb8bf80aded0a04fd88155535667
Trying to get experience on pack assembly and maintenance using laptops and power tools

So you run a GH @60V(using the 12v inc), but restrict amps through a CA? Do you notice a temp diff, significant performance in torque, or battery stamina?

Hope this is not a HJ, figured MtnBik would want this info as well.

 

[mountain biker]

okay.
S06P 250W Torque Simulation Square Wave Controller
on this controller it states 24/36 volt and like 14 amp max...

so if I take a 24 volt battery and puts out 20 amps burst current and like 14 amps constant current. my controller limits to 14 no matter what..i think they controller had plus or minus one amp written on it.....

so then I take 24 volts times 14=roughly 340 watts... can I use this on a 36 volt motter? lets say q100h what would be my consenquences...what would be my benefits

 

[d8veh]

I think the S06S is better for the Q100H. Those motors don't run very well sensorless. The Q100H can take a fair bit of current. If you only want 14A, there's the normal Q100. They're only offering the Q100H in 201 rpm at the moment, which is 15mph. If you run it with a 24v battery and controller, it would only so 10 mph, plus it wouldn't have enough power unless you're very light.

 

[mountain biker]

what I am not following here is if I get say a q85 for it comes in a 24 and 36 volt...

now the speeds I think are roughly 200rpm and 300 rpm motor....

now if I get a 24 volt for 200 rpm
and if I get a 36 volt 200 rpm


wouldn't my speeds be the same at the end...

I get how the the 36 volt at 15 amps would be a quicker start up to get to 200 rpm because it would have more watts applied to the motor.

what am I missing here?

 

[d8veh]

24v 201 rpm motor does 15 mph at 24v and 22 mph at 36v
36v 201 rpm motor does 10 mph at 24v, 15mph at 36v and 18 mph with 44v (12S)

You'll see approximately 10% more speed than those figures because the battery voltage averages about 10% above nominal.

The motors voltage markings don't mean anything. The motor doesn't care how many volts it gets, but the volts affect the speed, which is why they write it on the label.The different speeds are achieved by the the way they wind the motor. The lower the voltage, the more turns are needed to get the same speed.

The Q100 comes in four different windings that I've seen: 328 rpm at 24v; 201 rpm, 260 rpm and 328 rpm all at 36v. The 24v 201 rpm is probably the same as the 328 rpm 36v one, but with a different label.

 

[mountain biker]

hey appreciate controller advice very cool on that....man I bet you saved a lot of people a lot of heartache on their ebike sir. d8veh. appreciate all feedback.


I was just looking at q100h motor stats from bms. and they said at 38 volts 12 amps...the motor produces about 22 nm. now the esimiluator shows a q85 at 24 volts and 14 amps producing 28 nm....also simulator shows 16 mph. roughly on flat.... how can this be less wattage and with a few more amps it is faster..less voltage even...are these stats doctored... I thought I read somewhere that these motors were all producing 40nm....whats the deal here?

 

[d8veh]

Which esimulator are you referring to? The Q85 is smaller than the Q100, so I can't see it making more torque. The Q100H can run with 20A, which means about 600W of real power at 15 mph. Peak power comes at about 2/3 Max rpm. Peak efficiency at about 3/4 Max rpm. Torque is different at every speed, so it's not a good measure unless you know what speeds you're comparing. Torque is maximum at zero rpm, when your motor and controller go into melt-down.

 

[mountain biker]

http://www.electricbikesimulator.com/drive.php?id=40&language=enmi


both motors at 24 volts according to the 24 volt simliuator produce 28 nm....the q100h is at 15 amps the q 85 is at 14 amps.
im not saying they are correct, I have no idea...obviously you guys who actually ride these things have a better idea.
so then is 28 nm a reasonably amount of power for 175 pound rider on say 50 pound of bike?
and why is no one liking 24 volt?

however though I am still not grasping....the whole 200 rpm thing...it seems like 200 rpm at any v oltage is 200 rpm.... I am assuming then that these smaller motors can not get enough power to reach 200 rpm....is that the idea?

I always had the assumption that a 26 inch tire at 100 rpm was like 8 miles lets says...just uder 8.5 so 200 rpm seems like it should be 16 mph. now I get it maybe the tire is 25.5 inches because its flat...or maybe its jacked up to 26.5 inches or whatever.....

 

[Ykick]

24V is last century technology. Why bother when there's so much good 48V gear out there? More battery energy (Wh) density and lower wiring losses given the same wire size. If it's too fast merely turn the controller speed down.