Anyone know why my forsen hub won't go any faster with 60v ? I put 60v of fully charged batteries on and could not go any faster. I would have thought that I'd get a little increase in speed. I was going into the wind but I couldn't even get over the 27 mph speed that I got with 48v. It went up to 27 mph and it didn't go over. It's a geared brushless hub motor.
I go from 48v to 60v and no increase in top speed
- Thread starter morph999
- Start date
Ypedal
100 TW
I would say you found it's limit.. the extra voltage will only result in more heat ( were things like.. HOT>.. after this ride ? )
edit to add " The wind is a huge factor !! "
edit to add " The wind is a huge factor !! "
Russell
1 MW
Morph,
What's the no-load speed at 48 and 60V?
-R
What's the no-load speed at 48 and 60V?
-R
ok....I just did it...lol.... 44.6 mph ....not bad so maybe it was the wind? Or maybe I need 72v ? Since I mounted the speedometer to the front wheel, I just went in there and lifted it up and push the throttle....44.6 and that's after I went riding for 20 min so maybe more than 44.6
Russell
1 MW
Ok so what was it at 48V?
-R
-R
Russell
1 MW
Something is goofy there, you're saying at 48V your no-load speed is almost 44.6 mph and your top speed on the bike at 48V is 27 mph?
It would be nice to know how much current you're drawing out on the road.
I think ElectricEd may have been on to something in this post;
http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=8745&st=0&sk=t&sd=a&start=45#p133895
-R
It would be nice to know how much current you're drawing out on the road.
I think ElectricEd may have been on to something in this post;
http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=8745&st=0&sk=t&sd=a&start=45#p133895
-R
Russell
1 MW
Your weight isn't the problem, it kinda looks like that motor was made for a 20" wheel.
-R
-R
Drunkskunk
100 GW
very likely you're hitting the current limit of the controller.
but it could also be the motor is at or over it's limit at 48, and nothing will make it faster. the fact that its no load speed is 44, and the loaded speed is only 27 suggests it's beyond it's peak.
but it could also be the motor is at or over it's limit at 48, and nothing will make it faster. the fact that its no load speed is 44, and the loaded speed is only 27 suggests it's beyond it's peak.
Russell
1 MW
Drunkskunk said:
That's possible but since he achieved the same speed at 60V as he did at 48V it's probably more likely the motor was made for a 20" wheel. Just doing a quickie calculation his no-load speed in a 20" wheel would be about 34 mph at 48V which should be in the vicinity of 27 mph on the road.
The controller theory could be tested of course by changing it out or doing the soldering the shunt mod.
-R
yeah, what if I used a 40 amp controller ? I'm assuming the one I have is probably 30 amps. Like this one....it's only $75
http://cgi.ebay.com/72V-1500W-brushless-controller-for-E-bike-scooter_W0QQitemZ300276897869QQihZ020QQcategoryZ11332QQcmdZViewItem
I'd like to buy that controller and then put two 36v 8ah NiCD batteries on it. What do you think?
http://cgi.ebay.com/72V-1500W-brushless-controller-for-E-bike-scooter_W0QQitemZ300276897869QQihZ020QQcategoryZ11332QQcmdZViewItem
I'd like to buy that controller and then put two 36v 8ah NiCD batteries on it. What do you think?
Russell
1 MW
Knowing how much current is being drawn would help a lot.
Get a WU meter
-R
Get a WU meter
-R
Russell
1 MW
morph999 said:
Put some of the same connectors on the WU meter as you have between the battery and the controller and you can simply open the circuit and insert the meter. If you want to read it while you are riding though you'll need to extend the wiring so you can place the meter in view.
-R
Morph, I have a WU meter, why don't you just bring the bike over again and we can see what is holding you back, I think it might be the amp draw causing the voltage to sag as well as the controllers amp limit. We might be able to modify your controller for more amps depending on the fets is has.
Russell
1 MW
Something you guys should look at is the ebikes.ca simulator. If you select ANY motor designed for a 26" wheel and run the simulation at 48V you won't get anywhere near a no-load speed of 44.6 mph. However run a motor designed for a 20" wheel using 26" parameters and you will get the high no-load speed. The problem is, and this is what ElectricEd was getting at in his post that I referenced earlier, the motor won't be able to reach those speeds so it will be operating at a lower efficiency and will draw more current. Another tip-off that this motor is ill-suited to the current rim is that most motors are designed to run at full throttle at around 80% of the no-load speed. If you look at Morph's no-load speed at 48V of 44.6 mph multiplied by 0.8 you get a target speed of 35.7 mph. That's an unrealistic speed for a motor at 48V but if you do the same calculation for the motor in a 20" wheel you get roughly a design speed of around 27 mph which IS a perfect speed for 48V.
FWIW,
-R
FWIW,
-R
Almasi
100 W
morph999 said:
That will make it faster...but really, you need more current not more voltage, just swapping your controller for a 40 or 45 AMP at 48 Volt will make it faster and probably more efficient than running 72 Volt at the same 45 AMP...and you will probably get same speed with 72 or 48 Volt at 45 AMP (not a lot more if it does increase)
Just use a 45 AMP controller (if your motor can take it) and run it at 48 Volt...forget the 72 Volt with that motor(in a 26'').
Robin
Ok. Well, I was thinking that if I'm going to be getting a controller, why not upgrade but maybe we can solder the shunt.
Anyone know what this thing does?
does that prevent your motor from getting too hot? Maybe I could use that if I was going to go to 72v
Anyone know what this thing does?
does that prevent your motor from getting too hot? Maybe I could use that if I was going to go to 72v
karma
10 kW
no that would work for a battery pack if the cells got to hot. im sure the amps would kill it right away.
nicobie
100 MW
Fuse?
:wink:
:wink:
