Hub Motor questions

[tmho]

I have a 48V 500W rear hub motor. I have not yet installed it to a bike. I have tested it. The no load maximum speed is just around 30km/hr. I wanted to increase the maximum speed to about 40km/hr under load. My weight is just about 140lbs. Can I do that just by replacing the controller with a 800W or 1000W controller?
In such a way, I think the current will be increased. But when I check the cable coming out from the hub motor (as attached), the wires seems quite thin. Will the wires be able to handle the increased current?
In case the wires are too thin, I want to replace the cable with thicker wire. I have searched ebay using "hub motor cable", but I could not find any similar cable (with 5 thinner wires and 3 thicker wires). What is the correct name for that cable?

 

[Drunkskunk]

there are 2 things that may be limiting your speed to 30. It could be some form of speed limiter. Often a controller will have one for use where it's legally required. If you have 2 single wirres that exit the controller and plug together, that's the limiter. unplug it and retest. Show us a good pic of the controller, we may be able to tell if that's the issue.

Otherwise, you need more voltage. For a cruising speed of 40KPH you need a free running speed of 50kph. You are getting about 0.83 KPH per volt, so if a 36 volt battery got you 30 KPH, then 60 volts will get you the 50kph free running speed you need.

 

[tmho]

there are 2 things that may be limiting your speed to 30. It could be some form of speed limiter. Often a controller will have one for use where it's legally required. If you have 2 single wirres that exit the controller and plug together, that's the limiter. unplug it and retest. Show us a good pic of the controller, we may be able to tell if that's the issue.

Otherwise, you need more voltage. For a cruising speed of 40KPH you need a free running speed of 50kph. You are getting about 0.83 KPH per volt, so if a 36 volt battery got you 30 KPH, then 60 volts will get you the 50kph free running speed you need.

Attached pls find some photos of the original controller. There are 2 single wires (gray color) that exit the controller but do not plug together. My test was done with them not plugged together. (I have heard that this controller was programmed by software, but I am not sure.)

 

[Drunkskunk]

It does not appear to be an Infiineon, Crystalyte, or Greentime controller board. I'm not sure what that is. Being a 9 FET controller means is should handle more power than that little motor can take. But whether it can be reprogrammed or not depends on the manufacturer.

But you'll need more voltage to reach your goals, so unless that controller is rated for 72 volts, it will need replacing.

 

[tmho]

Will a shunt modification (like the one in http://endless-sphere.com/forums/viewtopic.php?f=28&t=46891) on the controller help in increasing the maximum speed?

 

[amberwolf]

The shunt just measures current.

Modifying the shunt changes how much current the controller thinks is passing thru it.

If your system is limited in speed because of current, then increasing the current it outputs will speed it it up, at least until something melts or fails due to overheating.

 

[wesnewell]

Do you have a link to the kit you bought. That would be helpful.

 

[tmho]

Do you have a link to the kit you bought. That would be helpful.

That was many years ago and so the link does not exist anymore.

 

[d8veh]

What motor is it? Does it have any markings?

 

[tmho]

What motor is it? Does it have any markings?

It is a brushless motor from Fusinmotors in China. There is no marking on the motor.

 

[amberwolf]

As a warning, if this is the same one I used on DayGlo Avenger, you may either break the clutch or kill the hall sensors using more power than the original controller puts out. See that thread (search by title for that bike name) for the problems I caused with it using it with a higher power controller.

It doesn't look large enough to be the later higher-power model, which might be able to take the bigger controller--see the Fusin 1000w test/review thread for that one, and the Delta Tripper thread.

 

[John in CR]

Yes they had some issues with their clutches in the earliest models, which was in late 2008 when I got a pair. One the clutch slipped and the other it was ok, pushing much more load than yours...that is as long as you don't have an unusually heavy ebike.

For more speed you need to go to a higher voltage, from 48V to 60V+. You don't want to increase the current, and with your light load you don't really need it.

 

[tmho]

Thanks for the suggestions from amberwolf and John in CR. My motor was ordered on Oct 2009. But sorry I do not understand what the clutch is in a hub motor. Do all hub motors have a clutch?

 

[amberwolf]

Just the ones with gears, generally (like Fusin's), though there are versions that are clutchless (including a test version by Fusin), which do not freewheel when not under power, and can have quite a bit of drag due to the gear reduction/motor if you have the throttle off.

Pictures in this post of the inside of the Fusin I have, after I broke the clutch:
http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=15570&p=550415&hilit=clutch+dayglo+avenger+clamp#p550415

and after replacing it with a spare and adding ATF to try cooling experiments (whcih never did happen, with intervening events):
http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=15570&p=576368&hilit=clutch+dayglo+avenger+clamp#p576368