New, need answer to motor wattage

[jacksmith24]

Hi all,

My son picked up a Currie Scoot-E electric scooter, 24v with 100 watt motor. He's about 130 pounds, so the scooter seems under powered. I can easily pick up and install a 300 watt motor, but before I do I wanted to know this: What does upping the motor wattage do? Will it get more torque, more speed, or both? I don't really need more speed (not that it would be a bad thing), but it needs more "off the line" torque, especially on hills around here.

Also, is it safe to assume that tripling the motor power will reduce the battery life by 2/3 or more? He's only travelling four miles total (2 miles each way to a bus stop).

Thanks,
Jack

 

[TINO.sk]

Hi,I want to help,you´ll increase engine output,may burn controller.Under load.But will work.Better for you is exchange stronger controller,because you can watch temperature of engine.

 

[r3volved]

Your wattage is the motors power rating. More watts = more power. Higher volts can push less amps to achieve same wattage as lower volts - at reduced heat to controller and motor :: V*A=W
Voltage also has a direct relationship with motor RPM.

@24V you need just over 4A to reach 100W - 12A to reach 300W.
@48V you only need 6A to reach 300W.

2x higher V would need a new controller
3x higher A probably also requires new controller

Your battery then needs to be able to support the max continuous amperage you're looking for at the voltage you decide.

A 24V10Ah battery is 240Wh (240W per hour) and would require a 12A continuous discharge. You would get under an hour use at 300W or 2.4hrs at 100W. To increase duration, you need a higher capacity (Ah) battery to produce a higher Wh at the same voltage. 24V20Ah is 480Wh and you will get 2x duration. Upping the capacity also increases your discharge capabilities at the same voltage.

 

[jacksmith24]

Thanks, guys! I need to clarify:

This scooter has no controller like other more modern scooters - it has a simple thumb-paddle throttle, though it is variable.

I currently have two 12v10Ah batteries in series - as it was originally designed. I had heard that I can go up in motor wattage, or I could add another 12v battery and run the motor at 36v, but I'm not exactly sure what the extra voltage would do other than increase run time. Thoughts?

Thanks,

Jack

 

[r3volved]

36v would increase the power

 

[Voltron]

The wattage ratings on the motor are mostly a suggested guideline about how much power it can handle continuously. So putting a bigger motor on the same wattage output from the controller won't change much...but it will prob run nice and cool. You have to look into changing controllers to one that outputs more power if you want more grunt off the line.

More voltage is almost always better too, esp if your stock controller can handle it. More volts equals more motor rpm, and less amps being used for the same power equals less wasted wire and motor heating. But then you have to keep your eye on the voltage, as the low voltage cutoff in the controller won't kick in at the right time. Plus you need a 36 volt charger now, and if it's a brushed motor things get hotter and sparkier, etc.

It's always something with hotrodding...


Edit....I just reread that, there's no controller at all? Is it just varying the voltage thru a rheostat or something?

 

[amberwolf]

This scooter has no controller like other more modern scooters - it has a simple thumb-paddle throttle, though it is variable.

I can almost guarantee you there is a controller, even if a simple one, either built into the motor or into a box somewhere between the throttle and the motor.

Otherwise your throttle would need to be as big as the motor to dissipate all the wasted power whenever it is not at full throttle but is using the full 100w, and you'd definitely notice the heat coming from it when you were using it that way.

 

[r3volved]

Is the motor brushed or brushless?

 

[jacksmith24]

Well, I've had every component off the frame, and if there's a controller it must be built into the motor. I don't have pics handy, nor can I find them online (the scooter is from around 1998 or so). I'm not sure if the motor is brushed or brushless, a there aren't a lot of markings on it and I've not had it apart.

As far as I can tell, the throttle is just a large rheostat. If I recall, power runs from the battery pack to the motor and ties in with the wires from the thumb throttle. I'll get pictures tomorrow.

Thanks, guys!

Jack

 

[amberwolf]

Definitely curious to see the pics; I worked out "controllerless" brushed-motor ebike drives with switches between different numbers of batteries in series, and tried some potentiometer versions, most of which just smoked immediately, but even the largest ones I had (wirewound stuff off a stove, I think, about the size of my fist), would get really hot, under some loads so much that it coudlnt' be touched. And didn't really work very well for motor control.... never even made it onto a bike to road test.

I now have a very large Luxtrol stage lighting dimmer that is bigger than and heavier than my x5304 hubmotor, that could probably be used to control a brushed motor successfully, but I haven't ever gotten around ot trying that.


So, it is possible it could be what you think it is...but it is more likely that it is either a small MOSFET controller, could potentially be an early SCR controller, too.

 

[r3volved]

I mentioned the brushed motor cause my old razor scooter came with a brushed 100W 24v and no 'controller'. The 'controller' was just a little black box (1-2" square) with a breaker and a relay that sent all 24v through the throttle when the 'ignition' button was depressed.

The throttle just potentiated the wattage right to the motor. It was like their first gen E100 though so I don't know how common that is anymore (or in past). Isn't that how a typical kids power-wheels works?

 

[Dauntless]

I'm coming up short in looking for a schematic, a replacement motor or controller., etc. Never had the chance to tinker with one of those. First thing I'll say is follow the wires back from the motor to?? I'd expect it to plug right into the controller.

So, to play out a hunch, I'd guess your motor is a MY6812. Because that's what is on the 100w Razor, the whole line of which tend to be interchangeable with the Currie. I'd expect you could use a bigger Razor or Currie controller, but I'd like to see the controller from yours before I'd be sure. Only 100w, as mentioned it might just turn on full speed, or full SLOW at 100w, so it's possible there's no controller. Sometimes it's in with the battery. Need to know what plugs need to be on the new one.

If you put a 300w 24v controller on there, it might go uphill better but it might get real hot, too. If you put a 36v on there that's 400w it's about the same heating risk as the other, but it'll go faster on flat ground. Just a guess, but I think I'd want to try a 36v with 300-350w on that motor if I could find it to fit. This one might work. Don't know if your current throttle would work with this controller, $12 less without a replacement. http://www.monsterscooterparts.com/ct-201k-control-module-razor-mx350-9.html

My suggestion is if you replace the motor, no point in stopping at 300w. How long do you expect him to weigh 130lbs? With the controller and a new throttle it'll run almost as much as going 650w, this with the Razor MX650 dirtbike powerplant, whouch I do have wonderful experience with. http://www.monsterscooterparts.com/36-volt-650-watt-motor-razor-mx650-dirt-rocket.html here's the 4 wire controller http://www.monsterscooterparts.com/ramxmxdibico.html which requires the 4 wire controller. http://www.monsterscooterparts.com/razor-variable-speed-4-wire-twist-grip-throttle-with-36-wires.html Cheapest combination, if you get one different you need both to match. They have 5 and 6 wire, also, they cost a little more. http://www.monsterscooterparts.com/5-wire-throttle-control-module-kit-razor-mx650-ver-1-7.html

Haven't rode a Scoot-E, sure looks like a stable platform, might work great at 650w and more. Up to you to prove it, though.

 

[jacksmith24]

Hi guys,

Here are the pictures. I tried to get pics of the wiring harness and motor, as clearly as I could.

So, definitely not an MY6812. The throttle is variable, and has only two wires coming from it. So far as I can tell, there's no controller in the throttle housing. The motor has three wires coming out of it: I would have expected two. Perhaps there is a controller of some sort in there. I know it has thermal limiting, because we pushed it too hard today and it shut down.

It appears that the XYD series motors will fit (at least some of them have matching bolt-hole patterns). I think maybe upgrading is the only way to go. I'd appreciate more input, based on my wish list below:

- I'd like to keep the scooter frame, building on what's there as easily as possible. I know I can get motors from eBay if nowhere else.

- It currently has 100W motor - I'd like to get enough power to make getting up mild hills easier, while - if possible - getting at least 5 miles of travel, around 35 minutes.

- I'd like to stay at 24V, though going to 36V isn't out of the question entirely.

So, ideas on how best to do this while keeping it as inexpensive as possible?

Thanks! Jack

 

[Dauntless]

If you're saying it's not a 6812 because of a variable throttle, that's wrong, a 6812 will run variable. It's just with these low power items sometimes there's only full on and off, nothing inbetween.

Well, let's see. If you want to try the 300w controller first, that's the cheapest. Hillclimbing will be suspect. If you want to try out a heavy hitter controller that could take a bigger motor later, you could take a stab at: http://www.ebay.com/itm/Electric-E-Scooter-24v-1000w-Controller-Throttle-Kit-/170395874218?hash=item27ac62b3aa (I always feel funny when I haven't tried out all the claims of it myself.) You run it at 24v on your 100w motor, which may or may not offer 20a and overwhelm the XYD. My feeling is, as long as you don't damage anything OTHER THAN the motor, that 100w is much of a loss if this doesn't last. This controller is supposed to run 36v and 48v at up to 20a. Throttle included, eh?

As for the motor, is there a gearbox? (Pictured is an XYD, not all have gearboxes.) If so, the RPM is lower so that impacts your choice on a motor replacement, which you need to be thinking about.

If this motor is going to be compatible, here's an option. http://www.ebay.com/itm/CURRIE-ELECTRO-DRIVE-500-WATT-24V-DC-28-A-electric-motor-for-scooter-500W/321848107764?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20131003132420%26meid%3D7a184823ef3d4c688f56bc374cdf3cd2%26pid%3D100005%26rk%3D3%26rkt%3D6%26sd%3D151750489168 I'm thinking you can try this out at 24v with the batteries you have then if you want to experiment with 36v you're all ready. With either the original motor or a replacement, raising the voltage raises the RPM, which will probably be good. I'm guessing that eBay motor at 36v/20a would run a 135 pounder at 20mph, give some respectable hillclimbing, etc. The motor says 28a, you might even try a 36v/1000w controller.

 

[jacksmith24]

Hi again,

I was saying it's not the MY6812 because the dimensions are wrong, and this one has three lead wires going in (like one of you said, probably an integrated controller), and the 6812 I saw had a different mount.

There's no gearbox on the motor, the chain runs directly from the motor shaft to the rear sprocket. However, and I'm wondering if this is how the newer motors work, it DOES have a free-wheeling bearing that the sprocket is mounted to. When I get a new motor, will I be better off swapping the sprocket with bearing onto the new shaft, or will the newer motors freely "coast" anyway?

I agree - if the 100W motor is all that gets damaged, no great loss.

So it sounds like the best thing to do is go straight to something over 300W. I see LOTS of 450 Watt motors that will bolt directly on.

A thought occurs - if we put a 450W motor on there without a controller - is there any downside besides the fact that there's no variable throttle? I ask because we're on a limited budget right now, and if we can get the larger motor to work without a controller for NOW, we can add the comfort features later. I'm not worried about under voltage protection, etc., for the time being, as this is is being ridden 16 minutes (2.3 miles) one way in the morning, locked up, then driven 16 minutes/2.3 miles home and then recharged.

So, to sum up, my new questions:

1. Do I need this free-wheeling bearing?
2. Do I absolutely need a controller?
3. Does it seem that he'll be able to make this 5 mile roundtrip without charging issues? Batteries are brand new, 12V 10Ah.

Thanks again!

Jack

If you're saying it's not a 6812 because of a variable throttle, that's wrong, a 6812 will run variable. It's just with these low power items sometimes there's only full on and off, nothing inbetween.

Well, let's see. If you want to try the 300w controller first, that's the cheapest. Hillclimbing will be suspect. If you want to try out a heavy hitter controller that could take a bigger motor later, you could take a stab at: http://www.ebay.com/itm/Electric-E-Scooter-24v-1000w-Controller-Throttle-Kit-/170395874218?hash=item27ac62b3aa (I always feel funny when I haven't tried out all the claims of it myself.) You run it at 24v on your 100w motor, which may or may not offer 20a and overwhelm the XYD. My feeling is, as long as you don't damage anything OTHER THAN the motor, that 100w is much of a loss if this doesn't last. This controller is supposed to run 36v and 48v at up to 20a. Throttle included, eh?

As for the motor, is there a gearbox? (Pictured is an XYD, not all have gearboxes.) If so, the RPM is lower so that impacts your choice on a motor replacement, which you need to be thinking about.

If this motor is going to be compatible, here's an option. http://www.ebay.com/itm/CURRIE-ELECTRO-DRIVE-500-WATT-24V-DC-28-A-electric-motor-for-scooter-500W/321848107764?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20131003132420%26meid%3D7a184823ef3d4c688f56bc374cdf3cd2%26pid%3D100005%26rk%3D3%26rkt%3D6%26sd%3D151750489168 I'm thinking you can try this out at 24v with the batteries you have then if you want to experiment with 36v you're all ready. With either the original motor or a replacement, raising the voltage raises the RPM, which will probably be good. I'm guessing that eBay motor at 36v/20a would run a 135 pounder at 20mph, give some respectable hillclimbing, etc. The motor says 28a, you might even try a 36v/1000w controller.

 

[Dauntless]

Freewheels are a matter of taste, some like them better than others. I think the little Curries would benefit from one, but some Razors I've collected have had broken freewheels.

I don't know what your throttle really is, can't venture an opinion. If there's a rheostat in there, won't it burn up when there's 3-5 times the current running through it? I don't think you want to use that with something bigger. The bigger the motor the bigger the problem when you power it full on only. Somewhere here I have an old Razor with what seems like just on/off, but I never pulled all that apart to see what was really there. It's something like 100-150w, worked terribly. I wouldn't want to try that with something bigger.

Let's see, with the 24v/10a battery in a 350w Currie I made it 11 miles once, but it was new. 450w should get the 5 miles with that for awhile, except we don't know the condition of your batteries now. In fact if you're thinking of adding one new battery to the two you have, that quickly destroys all three.

I think there's plenty of motors to fit, 450w and bigger. If that motor I posted will mount, that's $54. The controller/throttle is $75. If you put the controller on with the old motor and the old batteries, it should be a bit stronger, but how much? Will it burn up? Only one way to find out. So if that doesn't work you then go with the motor and it would be better than the old one, but can you really go up hill as well as you want? If you then decide to go 36v that's 3 new batteries. They, those old cells will probably be going by then anyway. Or maybe you'll go lithium, that'll mean a new charger too.

 

[jacksmith24]

Thanks. The batteries are brand new, only have one charge cycle on them.

Still toying with ideas....

Freewheels are a matter of taste, some like them better than others. I think the little Curries would benefit from one, but some Razors I've collected have had broken freewheels.

I don't know what your throttle really is, can't venture an opinion. If there's a rheostat in there, won't it burn up when there's 3-5 times the current running through it? I don't think you want to use that with something bigger. The bigger the motor the bigger the problem when you power it full on only. Somewhere here I have an old Razor with what seems like just on/off, but I never pulled all that apart to see what was really there. It's something like 100-150w, worked terribly. I wouldn't want to try that with something bigger.

Let's see, with the 24v/10a battery in a 350w Currie I made it 11 miles once, but it was new. 450w should get the 5 miles with that for awhile, except we don't know the condition of your batteries now. In fact if you're thinking of adding one new battery to the two you have, that quickly destroys all three.

I think there's plenty of motors to fit, 450w and bigger. If that motor I posted will mount, that's $54. The controller/throttle is $75. If you put the controller on with the old motor and the old batteries, it should be a bit stronger, but how much? Will it burn up? Only one way to find out. So if that doesn't work you then go with the motor and it would be better than the old one, but can you really go up hill as well as you want? If you then decide to go 36v that's 3 new batteries. They, those old cells will probably be going by then anyway. Or maybe you'll go lithium, that'll mean a new charger too.