HPM5000B motorcycle application; questions, quandries and quibbles

[gestalt]

Okay, guess I have to start somewhere. I purchased this motor a couple months ago to use on my electric motorcycle project http://gestaltelectricmotors.blogspot.com/ . I am having trouble finding any information anywhere on someone who has actually used one of these motors for anything. So  figuring out what controller to use with this motor and how to connect them is  rather difficult.  In other words   HELP!!!  somebody...please...for the love of god there's gotta be someone out there that has worked with these motors. I'm starting to get all my parts together and all that's left is battery and controller. I also could use some advice in the realm of belt drive and gearing ratios.


frame- greenline stretch beach cruiser
fork- custom bobber/springer fork
front wheel- 26" disk mtnbike
rear wheel- 26" surly large marge with sturmy archer drum brake
motor- HPM5000B golden motor brushless 5000w
battery- LFP-4820 48V/20AH lithium phosphate
drive system- belt drive
controller-

[Draggin]

What you have in your hand is a brushless motor.  It has three leads on it. It is actually an a/c syncronous motor.  You will need a controller for a brushless motor.  altrax is a good one.  look at some EV websites you will soon get a feel for this stuff.  I think if you put that motor in that bike with that battery it would smoke the tires, brake the spokes, bust the chain, and grenade the 20Ah battery unless you take it really really easy.  That motor can draw 2-300amps but that battery only has about 20 amps maybe 40 or 60.  I would think that a better fit for that bike project might be the 1000w 48v motor. the bike would still do around 30mph!  But to be legal you have to keep it below 20mph most places.  You could go the other way and put that motor in a Harley and shoehorn 4 more batteries like the one you already have into it.  Now that would be cool!  I think I would start by googling electric vehicle associations in your area.  That way you could build on what they have done and not have to reinvent the wheel.         

[GoldenMotor]

You're going to need to use alot more Volts on that big guy

[ccbreder]

That motor would be over kill in that bicycle. You need to find a motorcycle frame, even a light one.
I would use two hub motors on your bicycle. 1000w front and 1000w rear. two controllers, two battery packs.
One throttle.

[gestalt]

well thanks for the quick responses guys, even if it wasn't exactly what  I wanted to hear.  my inspiration was this guys electric flat tracker http://www.youtube.com/watch?v=ljc0Gpt5_xI he used a etek brushed motor and I was thinking that the motor I have was somewhere in the same ballpark. I've allready built up a wheel with two and a half inch rims, extra thick spokes and a burly rear hub with a drum brake.  I'm using this guys fork building guide http://bikerodnkustom3.homestead.com/brainfork.html and I've even over engineered that design with dual front disk brakes and stronger steel. the whole rear end of frame needs to be redone with wider and stronger "chain stays" and the reinforcement that comes along with the motor and battery mounts.

is there maybe some battery/controller combo that would work for this motor or possibly have the controller limit the amount of juice being drawn from the battery. and I'm definitely not dead set on using the golden motors batter but would like to, maybe use two in tandem? there are just some things that I don't like about hub motors, although I do think that that new Magic Pie motor would be great on a single speed road bike with some strait bars and thicker tires. but I digress, this frame that I'm building off of is pretty damn sturdy and I figure I could load about 100lbs of EV onto it with some structural modifications.

so I put this question to you guys, can I still try to use this motor or will I be better off going with the mars brushless etek motor? I'm pretty dead set on the belt drive and the non-hub motor...oh, and the power. keep in mind from the get go the idea has been "dangerously underbuilt"

[GoldenMotor]

Hi,

5000W is enough to power a motor boat, able to take you to 150kph if you put enough voltage into it. Think about this, 48V1000W takes you to 48kph, 72V1500W takes you to 72kph, guess how fast the 5000W goes? So I guess you didn't have enough concept of what 5000W is capable off. But that's ok, as long as you are determined, you can do that speed if you want. I shall post a video of a finished 5000W product and it's abilities on the website soon, but the 5000W is mainly for professional motorcycle makers. You can do it as well, just follow the concepts of a motorcycle, change the motor to ours and add some gear ratios. However I'm no expert on that, I will make a new Electric Motorcycle/Car board in the future when our sales target hits the spot for the 5000W. If you plan to give up, just store it somewhere until we make a 5000W kit manual or how-to-install-onto-motorcycle guidebook. If you don't plan on giving up, then that's the spirit! I'm sure you can find some answers on the web.

[floatbike]

You could run the HPM 5000 at 24V.  It would not draw quite as much amperage.  Power output would be less than half, but still enough to dig out pretty good.
Another advantage of lower voltage is lower motor speed, making the belt drive system more practical.
At 24V your battery pack will be a lot lighter to.  You still would need 40Ahr of LiFePO4 batteries at 24V, large prismatic cells from an electric vehicle parts supplier would be one way to go.  A  100A Kelley controller will limit the max amperage to 100A, and is not very expensive.  100A at 24V is still quite a lot of power, more electric motorcycle than ebike I would say.

[gestalt]

Floatbike...you just blew my frackin mind. I mean, really speaking my language. Especially when it comes to the prismatic batteries. I took a little "field trip" to a123 systems headquarters because I found out it was only four miles from my house. I didn't find out much but I did get to look at one of their new prismatic 3.3 v-20ah cells and it was like ev porn.  But I'm sure they'll never sell direct to builders much like their cylindrical cells. 

So on a 26" bike how fast do you think I'm gonna be able to push this thing running it at 24v? I know it's not all about speed and compramises have to be made but speed is still an issue. And what size belt cogs would I need to use on the front and back respectively?

O a side note, I got the bike back together so I can see how it handles with that big fat wheel on the back. I have a spare rigid fork on it so I can use the burley steer tube from the original springer fork to make the bobber fork. A friend of mine just let me in on that he has a little welding station inhis electronics shop so I'm good to go as soon as I get my hands on a speed glass visor. Sure I'm not a purist but auto darkening just simplifies the whole welding proccess.

[floatbike]

How Fast?  That all depends on how you gear it.  The fastest you could go with 2400W would probably be about 40-45.  That is just my best guess.  Once you get above about 35MPH wind resistance starts to become large quickly.  For good low speed acceleration, and longer range it would be better to gear it to top out at a lower speed.
If the HPM5000 will spin up to about 3500RPM on 48V under moderate load, then expect about 1700RPM on 24V.  To go 35MPH a 26” wheel needs to spin 450RPM, so you need about 4:1 reduction with your belt drive. 
If it only goes 35MPH(30MPH in some states) then you can register it as a moped.  I think you would still need headlight, taillight, horn, mirror and maybe turn signals.  But you will not have to buy insurance, or pay registration fees every year.
For batteries you could probably use two Golden Motor 16Ahr 24V packs in parallel.  Also check out the 40 and 60Ahr 25.6V packs that batteryspace.com sells. 
You can also get the individual thunder sky cells and build your own pack, but it needs some form of over discharge protection.  A Kelley controller will do this.  And absolutly don't forget to put a 100A fuse near the batteries, and use all AWG 6 wire.
You might be able to get away with not using any type of cell balancing at only 24v, if you set the low voltage disconnect to 22V.  Since the cells can take 4.25V they will self balance to some extent during charging, which should be regulated at 29V.  I have been running several LiFePO4 batteries at 12.8V with no cell balancing.  This works fine, but the higher the voltage the greater the necessity for active cell balancing.  LiFePO4 cells do not pose a fire risk if overcharged like LiCoO2 cells do, they simply stop working.  Expensive mistake, but probably not dangerous.

[Bikemad]

Hi gestalt,

I'd like to throw in a few suggestions for you:

First let's take a look at the useful information we already have for this motor:

 

Now, let's consider using two LFP-4820 48V/20AH LiFePO4 batteries in parallel and a 120Amp controller of some sort.
That gives us a 48V power pack with up to 80Amps available for continuous supply and up to 120Amps max momentarily.

According to the data above:
Drawing 80Amps consumes 3.75Kw and produces 9.4Nm of usable torque@3300rpm. This gives us a maximum continuous power availability of 3.264Kw, which is almost 4.5HP!

120Amps will produce 14.79Nm of usable torque @2985rpm, or 4.6Kw output which is just over 6HP! but only for very short bursts.

If you're after top speed, go for around 5:1 reduction (with a 26" wheel) and expect to get a top speed of around 50mph @3300rpm. (660rpm at the wheel) 
50mph should just about be attainable on the flat with 3.264Kw (80 Amp continuous), but you might want to consider some form of rear suspension before you attempt to go that fast!

I used this to estimate the maximum speed with the available watts

Lowering the gearing will improve acceleration and hill climbing ability but will reduce the top speed as follows:

Estimated speed @ 80Amps continuous, max torque and forward force @ 120Amps Maximum
5:1 reduction = 50mph, max torque@wheel approx  75Nm, a forward force of around 23Kg (approx 51lbs)
6:1 reduction = 44mph, max torque@wheel approx  90Nm, a forward force of around 28Kg (approx 61lbs)
7:1 reduction = 38mph, max torque@wheel approx 105Nm, a forward force of around 32Kg (approx 71lbs)
8:1 reduction = 32mph, max torque@wheel approx 120Nm, a forward force of around 37Kg (approx 81lbs)

Dependant upon the pully ratios and diameters, you will probably have a pulling force of 100-150lbs acting upon your proposed belt drive system, which incidentally, will be trying its hardest to pull the wheel and the motor together, so both the axle and motor will need to be mounted securely, but must also be adjustable somewhere to allow the belt to be tensioned correctly.

And don't forget, you will also need some decent brakes and tyres (especially on the front) to be able to stop all this extra weight safely from high speeds, and hopefully regen will also help out a bit at the rear.

I realise these are just figures being thrown around at this stage, but hopefully they'll be useful figures!

Alan
 

[floatbike]

Bikemad,

That is a great little calculator, I particularly like it because it makes my guess on speed with 2400W look darn accurate.

[gestalt]

These new 5ah prismatic cells should be able to handle that. I REALLY need a better understanding of the controller connections though. Any assistance or suggestion are quite welcome. Thanks.

Pray tell what are these prismatic batteries of which you speak? I'm still shopping around for battery tech. I'm still leaning twords building an a123 pack.

[gestalt]

Yeah, I checked those out. I just don't think they have a high enough discharge rate to apply to my motor. I'm just hoping I can find a way for some of those new a123 prismatics to slip through the cracks into my bike otherwise I'm going to have to build my own pack and bms setup.

[e-lmer]

The A123 cells are just hardened LiFePO4 cells.

GM sells a 48V20AH pack, if you hooked 4 in series-parallel
you would get a 96V80AH pack.
http://goldenmotor.com/batterypack.htm
(ouch, batteries over 600 bucks each shipped.)

The motor will be from the hub motor page,
http://goldenmotor.com/hubmotors/hubmotorIndex.html
but for some reason they protect the link
to go back to the main site  (Kinda weird, Yao.) with:

Code: [Select]


if (self==parent)
 { document.write('<META HTTP-EQUIV="refresh"
    CONTENT="0; URL=http://www.goldenmotor.com">')
}

You can hit escape as the page loads to stop it from redirecting.

 HPM5000B with HPC100B should run a bike.

I have some questions about things like the voltage
limiter (since I can't get to 72V, I will have to run 96.)
and getting a twist throttle (no way I am using a pedal)

[gestalt]

I would like to go with the controller they have up on the site but I think for the purposes of adaptability I woul like to have a programable regen controller. I don't know about 24v, but do you think 36v setup would be a nice middle ground? I too would like to get up to 50mph but it's not like I would want to do that often. Something like a three speed current limiter switch to the controller.