Hub motor temps on 28 cell 3500li

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Iccarus
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Well I did my first temp checks today using an IR temp gage. On an 80F degree day I rode for about 3 miles then did a 3mi full speed run at 55 MPH. I stopped the bike and took temps and this is what I got so far. 104F on the outside edge of the motor rim and 113F on the inner most part of the motor rim. (brake side) The temps read a few degrees lower on the controller side of the motor. I did this several times and with hills and got the same numbers. Next I'll try longer runs to see if the temps just top out around 113F. Maybe today. Stay tuned.

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2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS

KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycle Analyst mounted in 48v Lipo 30AH battery Box. 16kw in an 89lb. Trike! O-54mph/5sec

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garygid
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Re: Hub motor temps on 28 cell 3500li

The 3500Li's motor is reported to be physically larger than the 5000Li's motor.

Is the 3500 motor brushless (with stationary coils inside and moving magnets), or "brushed" (the hot coils on the spinning outside, and the magnets stationary inside)?

With the heat-producing coils attached to the motor's outside shell (sure, still "inside" the hub motor's shell), it would seem that there would be the opportunity for better heat flow (conduction) out of the "brushed" motor, making it easier to cool, right?

But, with a motor where the coils are internal, the heat conduction path is only through the axel, and heat convection to the motor shell would be much less efficient at cooling the coils, right?

So, if one changes "external" (moving) coils to "internal" (stationary), increases the motor wattage, and decreases the motor physical size (less surface area for cooling), it would seem that the "new" motor MUST be designed to tolerate much higher internal (coil) temperatures (or have MUCH more external cooling), or the motor will overheat long before it reaches its "design" power rating (steady state). This would then effectively limit the motor to lower-power steady-state applications, even though it is capable of supporting the design power for short periods of time (perhaps with longer periods on cold days), right?

Do "all" brushless hub motors inherently have this need for increased cooling?

Thanks, Gary

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dogman
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Re: Hub motor temps on 28 cell 3500li

I have a temp probe inside my brushless bicycle motor. Monitoring temps I find a few generalizations.

At low speed, (low watts) the motor temp will reach a general high temp and then stay there. This temp will vary with weather, on a cold day, riding slow, the hub may stay very cool.

At high speed, or climbing hills at low speed, the watts to the motor increase and the temp will increase. Generally, if the hill never ends, or riding full throttle on the flat, the motor will inevitably get hotter than I want it to be. I draw the line where my cheap thermometer stops reading, at 160F. Once it reaches there, I start to ride slower, and at least keep the temp from going much higher than that.

Stopping alltogether is the best way to cool the motor, coasting down hills works too, or just slowing down. But the fastes way to cool off is simply a 5-10 minuite stop. I thought it took longer, but just 5 minuites has a noticeable effect. If you climb big hills, and are worried about heat, stopping at the top is the best thing.

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jdh2550_1
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Re: Hub motor temps on 28 cell 3500li

garygid wrote:

Is the 3500 motor brushless (with stationary coils inside and moving magnets), or "brushed" (the hot coils on the spinning outside, and the magnets stationary inside)?

The 3500Li is a brushless motor - generally speaking it has the same stator, winding and magnet layout as the 5000Li. I don't believe that the 5000Li motor is smaller than the 3500Li. Does your hub case fill the entire rim or is there a gap to make a 10" motor fit in a 13" rim. I thought the 5000Li motor fills the 13" rim and is thus the same general size as the 3500Li. Or is the size difference referring to some other physical dimension?

BTW, I think the 5000Li is a six phase motor, whereas the 3500Li is a three phase motor (don't think that affects the temperature discussion but it's one known difference). At least EFun used to use 6 phases.

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Iccarus
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Re: Hub motor temps on 28 cell 3500li

jdh2550_1 wrote:

Does your hub case fill the entire rim or is there a gap to make a 8.5" motor fit in a 13" rim. I thought the 5000Li motor fills the 13" rim and is thus the same general size as the 3500Li. Or is the size difference referring to some other physical dimension?

From the pictures I've seen the 5000 hub case is smaller and there are holes that form spokes so to speak. The case is not the full 10". Maybe they thought this would BETTER cool the motor but actually the lower surface area had the opposite effect.
I thought about trying to find small heat sinks that you could attach with the existing allen screws but the centrifical forces at high speed would be considerable, and the heat is coming from the coil in the center anyway. so far it's not a problem with the 3500li 28cells but I'm waiting for the heat. It would be nice to have some data on the critical temp point.

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2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS

KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycle Analyst mounted in 48v Lipo 30AH battery Box. 16kw in an 89lb. Trike! O-54mph/5sec

Mikie
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Re: Hub motor temps on 28 cell 3500li

Hey Guys-- as written in several earlier posts, a few knowledgeable people have said that 175 degrees F is the temp when these adhesives, that hold the wiring and magnets together, begins to deteriorate.(I work with high tech epoxys and that is a little lower that my experience but still not that far off) Thanks dogman for your info about your experience is around the temperature on your bike. I believe you are stopping at about the right temp: 160F maybe a bit on the high side I would stay around 150F to be sure. Has this conversation has revealed one of the inherent problems of the brushless hub motor? I noticed that Paulsen's auto conversion to dual hub motors keeps pushing their delivery date back, they say it is due to government tests yet I wonder if they are having a temperature dispersion issue and or how they have dealt with this in both their brushless hub motors?

http://www.poulsenhybrid.com/

I went to pick up the 6k72v mod and the batteries were all down, so the techs are still not sure the bike is out of the woods yet without the charger being around for them to test drive it....so the waiting continues....Best...Mikie

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garygid
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Re: Hub motor temps on 28 cell 3500li

The 5000Li's hub motor is about 8.5 inches (or slightly less) in diameter and there is about 2 inches of space between the outside of the motor case and the bulk of the wheel rim.

The tires are 130/60-13 both front and back.

Sounds like the 3500's motor is larger (about 10 inches)?

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garygid
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Hub motor Air Cooling

Page 3 of the "Air Cooling my x5" topic over on Endless-Sphere shows a picture of what one guy did that reportedly allows him to run 2000 watts through a "600-watt" motor: drill ventilation holes in the hub motor's cover.

With the windings cool (less resistance, so less heating losses) he reports a HUGE performance increase.

Might be food for thought?

Maybe 4 holes "near" the axle and 4 (staggered) holes near the rim of the 5000Li's left-side motor cover would do the trick?

Considerations:
1. Maintain sufficient structural strength in the cover.
2. Harmfull matter might possibly enter the motor.
3. Obviously, voids the 1-year motor warranty.

Apparently some older racing bikes with hub motors used large cooling holes (picture on page 2 of the same topic).

What do you think?

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garygid
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Re: Hub motor temps on 28 cell 3500li

It appears that the temperature limit switch in the 5000Li's motor is a "110 degree C" part (230 degrees F). QUITE hot indeed!

Indeed, it is far better for the motor to "never" get that hot, and (with some added warning prior to the cut-off point, for better safety) this motor-protection circuit is doing the right thing to protect the motor.

So, it appears that too-long periods of too-heavy usage (on too-hot days) need to be sensibly avoided.

Unless ... the motor can be cooled better.

Consider:
1. External cooling methods, increased airflow, fins, "fan" blades, etc.
2. Internal heat-transfer methods to better transfer the heat from the hot coils to the outside.
3. Internal cooling methods, air, liquid, etc.

There is no way around the fact that increased (average) power needs increased cooling.

Of course (if not already nearly too hot due to too-heavy usage), the 5000 has the high power available for acceleration (starts) and max speed (passing).

I am going to work on some form of additional cooling.
My suggestion (with a picture) for external "fan" blades is posted elsewhere.

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Mikie
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Re: Hub motor temps on 28 cell 3500li

Hey Guys-- Bad news, the tech took the 6kw72 volt out after charging batteries and the motor went dead and is hard to push, frozen up? This is running on 24 cells with a new controller. This tech has had major problems with Kelly: wrong motor 2 times and a bunch of bad controllers including one of mine. He is going to pull the 72 volt off and open it up then we will know more. I told him to put the old 3500watt motor back on for now. This is not good....M

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jdh2550_1
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Re: Hub motor temps on 28 cell 3500li

Mikie - before you blame Kelly what controller and what settings were you using? If you had the 300A controller and no limits set in the controller then you likely pushed 14kW or more through the motor. A hub-motor can't take the same sort of abuse as a regular motor like an ETek or Perm. Ask your tech how much power he put through the motor and how much he thinks it should be able to handle. Better yet - encourage him to post on here - the likes of Iccarus, garygid and MikeB are all doing similar things to you (and us as well).

I bet if you open up the motor you will find melted insulation power wires and/or a shorted hall sensor because of the heat build up. Well, that's what we found when we overcooked ours. That was our fault - not Kelly's nor the motor's.

Moral of this story: better wiring, better cooling or less power...

Good luck.

BTW, our 4500W motor and Kelly 300A/72V controller set at 70% has been bullet proof and creates a very rideable bike. We're still working the kinks out of the 5000W motor but expect to have that as reliable as the 4500W in the next week or so.

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Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas. No Worries." - JDH, CuMoCo || "Make Volts Not War" - anon.

garygid
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Re: Hub motor temps on 28 cell 3500li

John H,
A 300A 72v controller is about 20,000 watts. Is that continuous or peak rating?

Even 50% of that would seem to be a LOT more continuous power than a motor with a 5000-watt rating would handle.
What am I missing here?

An experiment with increased ("holey") cooling to lower the 5000Li's hub motor's internal temperatures appears very encouraging. More later when we get some real measurements.

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XM-5000Li, wired for cell voltage measuring and logging.

jdh2550_1
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Re: Hub motor temps on 28 cell 3500li

Gary - peak we put through it is actually 170A and only for brief periods. Our BCU (bike control unit - the "meta controller") will back off the power if it detects too much heat build-up.

Yep - I think holes are the way to go if you want to improve cooling. I have a few ideas of how to stop "contaminant ingress" (letting the hot air out but not letting the road grime in).

However, we're likely to go with upgraded power wiring for our production model.

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Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas. No Worries." - JDH, CuMoCo || "Make Volts Not War" - anon.

MikeB
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Re: Hub motor temps on 28 cell 3500li

jdh2550_1 wrote:

Yep - I think holes are the way to go if you want to improve cooling. I have a few ideas of how to stop "contaminant ingress" (letting the hot air out but not letting the road grime in).

However, we're likely to go with upgraded power wiring for our production model.

The belt drive on my Silverwing has a plastic shroud with openings for air, the rotating cvt plate has vanes to act as a fan to force air through the assembly. The air intake path has a sharp bend in it, to trap debris & water. There is also an air filter in place, essentially just an open sponge to catch dust. I can easily see something along those lines for air-cooling our motors. The hard part is to custom-fabricate something like that, but still keep it inexpensive.

John, speaking of your production model, you still looking at mid-June? Can you get an air-cooled assembly finalized by then, or am I sending my motor back to you for an upgrade? :)

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antiscab
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Re: Hub motor temps on 28 cell 3500li

jdh2550_1 wrote:

If you had the 300A controller and no limits set in the controller then you likely pushed 14kW or more through the motor. A hub-motor can't take the same sort of abuse as a regular motor like an ETek or Perm.

on this part i have to disagree.
you can push a hub motor as hard as an etek or any other motor for a short time. its the continuous power that gets them.
on my emax (1500w motor, 30A rated) i run a 400A 72v kelly controller.
i push the full 400A through the motor (battery side sees 250A, with voltage sagging to 48v)
cruising i can only push 50A through the motor, due to too much back emf.

its interesting what you say about hall sensor failure.
the halls in my hub motor failed on the original controller (which i modified for more power).
the failure happened after 15'000km of use at the higher (peak) power level.
i put it down to a one off failure, though it could be heat related.

Matt

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Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah
Vectrix 60Ah Lithium Tyres Fuel Registration Insurance cycle analyst replacement TC Charger
conversion
Spent so far: $5800 + $7000 + $1720 + $960 + $320 + $720 + $140 + $600
Cost to do it again: $2500 + $5600 + $1720 + $960 + $320 + $720 + $140 + $600
Cost for a Petrol bike:$6000 + + $1440 + $6000 + $800 + $1400 + $3200 servicing
Total spent: $17260
Total to do again: $12560
Total to have used a petrol bike: $18840
Total distance travelled so far: 79'120km

antiscab
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Re: Hub motor temps on 28 cell 3500li

garygid wrote:

John H,
A 300A 72v controller is about 20,000 watts. Is that continuous or peak rating?

Even 50% of that would seem to be a LOT more continuous power than a motor with a 5000-watt rating would handle.
What am I missing here?

all controllers are sold by their peak rating, while motors are sold (usually) by their continuous rating.
a kelly 300A unit can only do 100A continuous.

you are usually limited by back-emf at speed as to how much current you can push through the motor
on lower speed scooters, this determines top speed more than anything else.
on the 5000, you might not be, hence the available power at speed.

Matt

__________________

Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah
Vectrix 60Ah Lithium Tyres Fuel Registration Insurance cycle analyst replacement TC Charger
conversion
Spent so far: $5800 + $7000 + $1720 + $960 + $320 + $720 + $140 + $600
Cost to do it again: $2500 + $5600 + $1720 + $960 + $320 + $720 + $140 + $600
Cost for a Petrol bike:$6000 + + $1440 + $6000 + $800 + $1400 + $3200 servicing
Total spent: $17260
Total to do again: $12560
Total to have used a petrol bike: $18840
Total distance travelled so far: 79'120km

jdh2550_1
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Re: Hub motor temps on 28 cell 3500li

MikeB wrote:

John, speaking of your production model, you still looking at mid-June? Can you get an air-cooled assembly finalized by then, or am I sending my motor back to you for an upgrade? :)

We're looking at having bikes available July 1st (AFAIK, you're actually something like 6th in line). The air-cooled assembly most likely won't be on the first model year of bikes - but we will still be able to reliably meet our published specs by upgrading the power wiring. Yes, you'll be able to upgrade your motor if you want - however the motor you get will be reliable.

One note - the specs and price on the "Deluxe" model are going to change. We were hoping to be able to go with a 26 cell model - however, that set up wasn't going to work with the controller. So, we upgrade to the next controller which costs more money and at that point we decide to go with more cells as well. "Watch this space" for details of the performance increase :-) and the price increase :-( - (but just for the Deluxe model)

BTW it's been WET, WET, WET here the last couple of days. The bike I'm riding has been well and truly doused and is still proving bullet proof.

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Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas. No Worries." - JDH, CuMoCo || "Make Volts Not War" - anon.

jdh2550_1
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Re: Hub motor temps on 28 cell 3500li

Matt - It might be that your motor has better power wires? Our experience is that we've overcooked two motors in the first 10 minutes of use with peaks around 200A and about 70V. Both motors had melted the insulation on the power wires and the hall sensor wires (which were resting on the power wires). When the hall sensor shorts it creates the "hard to push" symptom that Mikie describes.

MikeB - don't worry we're burning up motors so that you don't have to! ;-)

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Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas. No Worries." - JDH, CuMoCo || "Make Volts Not War" - anon.

garygid
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Re: Hub motor temps on 28 cell 3500li

After making 8 holes (approx. 0.7" diameter) in the left-side motor-cover:
Running the 5000Li "full" throttle (in places over 61 mph by GPS) for about 30 miles on an over 80-degree day, we still managed to overheat the motor (again).

The cooling improvement was not as dramatic as we had hoped for. So, we are working on making and adding some small "scoops" to increase the flow of cooling air through the holes into (and out of) the left side of the motor casing. Hopefully that will give us enough additional cooling.

If not, we might need to make some holes in the right side of the motor casing (difficult to do without removing the stator from the casing). Hovever, this might allow us to create additional air flow, actually moving air THROUGH the motor (left to right) over the very-hot 9-spoke internal stator structure.

More Later.

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antiscab
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Re: Hub motor temps on 28 cell 3500li

jdh2550_1 wrote:

Matt - It might be that your motor has better power wires? Our experience is that we've overcooked two motors in the first 10 minutes of use with peaks around 200A and about 70V. Both motors had melted the insulation on the power wires and the hall sensor wires (which were resting on the power wires). When the hall sensor shorts it creates the "hard to push" symptom that Mikie describes.

Maybe, how thick are the wires in those hub motors?
i run 50A continuous.
ive got one of mine apart at the moment, so measuring it is relatively easy.
my motor is about 8" in diameter in a 10" wheel for reference.

Matt

__________________

Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah
Vectrix 60Ah Lithium Tyres Fuel Registration Insurance cycle analyst replacement TC Charger
conversion
Spent so far: $5800 + $7000 + $1720 + $960 + $320 + $720 + $140 + $600
Cost to do it again: $2500 + $5600 + $1720 + $960 + $320 + $720 + $140 + $600
Cost for a Petrol bike:$6000 + + $1440 + $6000 + $800 + $1400 + $3200 servicing
Total spent: $17260
Total to do again: $12560
Total to have used a petrol bike: $18840
Total distance travelled so far: 79'120km

garygid
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Hub motor temps on 5000li

I drove an un-cooled 5000li about 6 miles (over some hills, some places 45 mph, on a 70-degree day) and then tried to go up a steep hill, maybe a 150-foot climb in "one block".

The motor (already "warm", maybe even "hot"?) did well for the first 20 or 30 seconds, but then, losing speed, "scoot" battled on bravely. But, with lower and lower pitched groans of struggle, effort, and protest, she slowed to nothing, only getting about 80% up the hill. No red lights, no overheating lights.

With the brake-activation inhibiting the motor, it was "impossible" to try to restart going uphill. So, I backed up to turn around on the narrow one-lane (paved) road, and headed down in defeat.

Maybe with good cooling "scoot" could make it all the way up, but at the time, it was just too much to ask of her. Back on much flatter ground, we motored onward, almost as if nothing had happened (except for the dark cloud of shame that followed us).

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antiscab
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Re: Hub motor temps on 5000li

Gary,

I think its time you were the first to perform the shunt trick on a 5000.

Matt

__________________

Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah
Vectrix 60Ah Lithium Tyres Fuel Registration Insurance cycle analyst replacement TC Charger
conversion
Spent so far: $5800 + $7000 + $1720 + $960 + $320 + $720 + $140 + $600
Cost to do it again: $2500 + $5600 + $1720 + $960 + $320 + $720 + $140 + $600
Cost for a Petrol bike:$6000 + + $1440 + $6000 + $800 + $1400 + $3200 servicing
Total spent: $17260
Total to do again: $12560
Total to have used a petrol bike: $18840
Total distance travelled so far: 79'120km

garygid
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Re: Hub motor temps on 5000li

Try to bump it up from 100 amps max to 150 or so?

Already, I have trouble with too much low-throttle acceleration and the jerk.

You know, ... the Jerk behind the handlebars ... ?

But I am now concerned that there could easily be places where I could go "down going in", but might not be able to get back "up and out".

Until I get the motor cooling working better, a few other additions done, and gather more data, I will probably leave the shunts alone.

Next time I try that hill, I hope I have my PakTrakr plugged in and logging the current and voltages.

A neat logging thermocouple thermometer appears to be the
Lascar EL-USB-TC for about $83 inc. shipping from the SciProj.com site.

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antiscab
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Re: Hub motor temps on 5000li

garygid wrote:

Try to bump it up from 100 amps max to 150 or so?

Already, I have trouble with too much low-throttle acceleration and the jerk.

You know, ... the Jerk behind the handlebars ... ?

Ah, those are traits of poor analogue controller design (think curtis)
the current limit is enforced in hardware and the throttle gives direct control over PWM %duty cycle (motor side voltage).
better controller designs have the throttle control motor side current, rather than voltage.

not much can be done, aside from upgrading to a better controller (or being alot more adventurous :) )

Matt

__________________

Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah
Vectrix 60Ah Lithium Tyres Fuel Registration Insurance cycle analyst replacement TC Charger
conversion
Spent so far: $5800 + $7000 + $1720 + $960 + $320 + $720 + $140 + $600
Cost to do it again: $2500 + $5600 + $1720 + $960 + $320 + $720 + $140 + $600
Cost for a Petrol bike:$6000 + + $1440 + $6000 + $800 + $1400 + $3200 servicing
Total spent: $17260
Total to do again: $12560
Total to have used a petrol bike: $18840
Total distance travelled so far: 79'120km

Iccarus
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Re: Hub motor temps on 5000li

It's funny you mentioned the shunt mod. I just posted on another thread that I thought that it actually made the startup a little smoother. I'm not 100% on this as the two bikes are far apart but I find start ups in high speed mode to be a little sensitive on the one I'm riding now (without mod) a friend and I both felt it made the throttle a little smoother and responsive but thats not to scientific. Anyway if you decide to you really can just take the end plate off and do it with it on the bike. If you lay the bike down it will probably be easier as the solder won't run. (I know you guys like to do things the hard way, you'd probably take it off :) Just don't forget to disconnect the batt cables. (I know because I earned the nickname flash when I touched the wrong thing with the tip of the soldering iron!) I had turned the breaker off thinking I was safe. oops! I'm trying to decide whether to do this one too. You can blow the controller if you're not carefull. BTW I was wondering is there a chance my 3500 is running cooler (the motor) because of the higher voltage.

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2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS

KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycle Analyst mounted in 48v Lipo 30AH battery Box. 16kw in an 89lb. Trike! O-54mph/5sec

garygid
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Re: Hub motor temps on 5000li

Is it a lack of fine control of the PWM at low percentages?

Or, is there a minimum PWM percentage, and a minimum incremental increase in this "digital" controller (like 1% min. and 1% steps)?

If the lowest controller power "settings" are 1/100 and 1/50, that might explain the lack of a smooth low-throttle response.

Also, there might possibly be a small "dead zone" designed into the throttle response, to help eliminate something like a drive "flutter" or variation due to noise on the throttle input.

In any case, a smoother control of low speeds would seem to be a big plus.

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XM-5000Li, wired for cell voltage measuring and logging.

garygid
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Re: Hub motor temps on 5000li

I just ordered the Lascar EL-USB-TC temperature logger from SciProj.com (it comes with a type "K" thermocouple).

I will report on how it does at temp. logging, and (if known) what the log format is.

If practical, I will try to add readin and display of the temperature (and time?) data to my PT Viewer program.

Yes, each PakTrakr "Remote" module reports an "internal" temperature, so maybe I will graph those values also.

More later.

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Cheers, Gary
XM-5000Li, wired for cell voltage measuring and logging.

jdh2550_1
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Joined: 07/17/2007
Points: 2338
Re: Hub motor temps on 5000li

Iccarus wrote:

BTW I was wondering is there a chance my 3500 is running cooler (the motor) because of the higher voltage.

Yup - it probably is running cooler because with higher voltages you'll draw lower amps resulting in less heat.

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John H. Founder of Current Motor Company - opinions on this site belong to me; not to my employer
Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas. No Worries." - JDH, CuMoCo || "Make Volts Not War" - anon.

Iccarus
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Joined: 12/20/2008
Points: 347
Re: Hub motor temps on 5000li

That's what I thought but it seemed to good to be true. I knew with higher voltage you could use thinner wire without it getting hot so naturally... the caps in the controller are what will probably go if somthing does right? Could I just replace them with higher rated caps?

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2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS

KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycle Analyst mounted in 48v Lipo 30AH battery Box. 16kw in an 89lb. Trike! O-54mph/5sec

jebbers
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Joined: 05/26/2009
Points: 3
Re: Hub motor temps on 28 cell 3500li

Hello Guys, My name is Jeb, I installed Mikes Hub motor. Here is the story..
I installed the kelly 220Amp controller at 70%, the scooter was completely gutless. so i tied 100%, the scoot was still super slow. I took it for a ride and only made it down the street before it stopped and had the dragging motor effect. Even at 100% the bike seemed much slower than it did stock. I have taken the motor apart but nothing looks out of the ordinary. The hall sensors dont look damaged and dont show any signs of rubbing. The electric coils just seem to large to spin freely inside the magnets. I dont understand what happened. Maybe the magnets shifted? It was only a 1/2 -3/4 of a mile and nothing looks beat up inside. Is the dragging effect normally caused by melted parts rubbing or magnets coming loose? any ideas? Anyways We gave up on the 6k motor and reinstalled his old motor after reading that you guys had run a 300 amp controller at 70%. Im going to try it tomorrow and see what happens. This looks like a super cool forum. I need to spend a few nights checking it all out. Thanks -jeb
http://img.photobucket.com/albums/v242/ilveleno/pics037.jpg

http://img.photobucket.com/albums/v242/ilveleno/pics046.jpg

antiscab
Offline
Joined: 07/07/2007
Points: 1600
Re: Hub motor temps on 28 cell 3500li

the dragging effect is caused by a short between two (or maybe 3) of the phases.
aside from rewinding, theres not alot that can be done.

Matt

EDIT: since this is the second motor to have failed after (short) use, its likely the failure is due to insufficient insulation between the windings. This results in rapid breakdown and a short between the phases.

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Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah
Vectrix 60Ah Lithium Tyres Fuel Registration Insurance cycle analyst replacement TC Charger
conversion
Spent so far: $5800 + $7000 + $1720 + $960 + $320 + $720 + $140 + $600
Cost to do it again: $2500 + $5600 + $1720 + $960 + $320 + $720 + $140 + $600
Cost for a Petrol bike:$6000 + + $1440 + $6000 + $800 + $1400 + $3200 servicing
Total spent: $17260
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Total distance travelled so far: 79'120km

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