Search found 238 matches

by hias9
Dec 10 2020 8:59am
Forum: EBike Technical
Topic: Maximum centrifugal load for hub motor wheel
Replies: 13
Views: 387

Re: Maximum centrifugal load for hub motor wheel

It probably allows even more than 200% rpm boost, but I am not going to try it with rim, tire and tube installed. I am also a bit worried about the spokes because they are only 13/14ga butted spokes. Yes, that is what I run the motor top speed on the flat. BEMF is only slightly above mosfet limit wh...
by hias9
Dec 10 2020 12:55am
Forum: EBike Technical
Topic: Maximum centrifugal load for hub motor wheel
Replies: 13
Views: 387

Re: Maximum centrifugal load for hub motor wheel

BAC4000.

But as I mentioned, these rpms are of course without load. While riding I don’t reach half of that value.
And if you want to run it deep inside field weakening area for a long time, I don’t think that would be very efficient.
by hias9
Dec 09 2020 10:45pm
Forum: EBike Technical
Topic: Maximum centrifugal load for hub motor wheel
Replies: 13
Views: 387

Re: Maximum centrifugal load for hub motor wheel

No, still wye not delta. It's just the fw that causes these no load rpms. Without fw Kv is about 11.7
by hias9
Dec 09 2020 9:36pm
Forum: EBike Technical
Topic: Maximum centrifugal load for hub motor wheel
Replies: 13
Views: 387

Re: Maximum centrifugal load for hub motor wheel

I am using torque control, not speed control. If I twist the throttle by 20% it results in 2500rpm. I guess no load speed at the max field weakening current it is set to (87.5amps) would be somewhere around 3000rpm at full throttle, but I don't want to try it. No load rpm without field weakening are...
by hias9
Dec 09 2020 8:47pm
Forum: EBike Technical
Topic: Maximum centrifugal load for hub motor wheel
Replies: 13
Views: 387

Re: Maximum centrifugal load for hub motor wheel

The problem when I set max field weakening current lower is that there is significantly less power available in the field weakening area and top speed would also decrease significantly. Yes, no load wheel speed at 20% throttle was a bit above 2500rpm which is 300kph or 186mph. I did not want to go f...
by hias9
Dec 09 2020 7:15pm
Forum: EBike Technical
Topic: Maximum centrifugal load for hub motor wheel
Replies: 13
Views: 387

Maximum centrifugal load for hub motor wheel

I have a 45mm magnet height hub motor with Hubsinks inside a 24'' DH rim with DH tires and DH tube, so significant weight on the outside and spokes are only 13/14ga butted. When using torque mode on the ASI controller with 25% field weakening current, no load speed is very high. I stopped at about 2...
by hias9
Dec 08 2020 8:28am
Forum: Items for Sale - New
Topic: Compact Field Oriented Controller, ASI + Grin, limited run
Replies: 1272
Views: 282764

Re: Compact Field Oriented Controller, ASI + Grin, limited run

The jerking I only have when running the motor no load. It's happening at higher rpms than I reach while riding. But even with current regulator bandwidth set to 0, while riding near top speed deep in field weakening area, I have about 15% less power and motor current at 100% throttle than have at 5...
by hias9
Dec 07 2020 12:59pm
Forum: Items for Sale - New
Topic: Compact Field Oriented Controller, ASI + Grin, limited run
Replies: 1272
Views: 282764

Re: Compact Field Oriented Controller, ASI + Grin, limited run

With my ASI controller the motor is jerking at some point in field weakening area. The problem I have is that with no load and some field weakening, only for the first 10-15% of throttle setpoint, more throttle results in more motor current and higher rpm. Around 15% the motor is jerking. And for 20...
by hias9
Dec 05 2020 11:35am
Forum: Battery Technology
Topic: Waste Heat Calculation Help
Replies: 8
Views: 393

Re: Waste Heat Calculation Help

Just R * I^2, so at 10A 0.8W for copper or 3.2W for nickel.
by hias9
Dec 05 2020 6:14am
Forum: Battery Technology
Topic: Waste Heat Calculation Help
Replies: 8
Views: 393

Re: Waste Heat Calculation Help

The amount of heating power (in Watts) is R * I^2 (Resistance * Current^2). The resistance of the wire (in Ohm) is c * (length in meters) / (area in mm^2) Use c=0,0171 for copper and c=0,0693 for nickel. So 12.6cm of 0.27mm2 wire would have a resistance of 8mOhm in copper and 32mOhm in nickel. To ca...
by hias9
Dec 04 2020 5:58pm
Forum: Battery Technology
Topic: Typical Internal Resistance of 18650 Pack
Replies: 16
Views: 799

Re: Typical Internal Resistance of 18650 Pack

The <38mOhm value for one cell I used is for 1kHz AC, for DC it's more like 50mOhm, and MOSFET resistance of the BMS could also be about 10mOhm and it was a bit cold so I guess everything is fine. Are you not using a BMS for this battery and do you also measure it (voltage sag) divided by (battery a...
by hias9
Dec 04 2020 1:33am
Forum: Battery Technology
Topic: Typical Internal Resistance of 18650 Pack
Replies: 16
Views: 799

Re: Typical Internal Resistance of 18650 Pack

Thanks for the info! What cells do you use in your 16s12p pack?
by hias9
Dec 03 2020 11:03pm
Forum: Battery Technology
Topic: Typical Internal Resistance of 18650 Pack
Replies: 16
Views: 799

Re: Typical Internal Resistance of 18650 Pack

I did not build the pack myself, so unfortunately there are no fotos. I was just asking if anybody can post the internal resistance of his pack. If I assume an internal resistance of 38mOhm (lygte-info.dk writes <38mOhm), so for a 14S10P pack combined cell resistance would be 58mOhm. The resistance ...
by hias9
Dec 03 2020 9:06pm
Forum: Battery Technology
Topic: Typical Internal Resistance of 18650 Pack
Replies: 16
Views: 799

Re: Typical Internal Resistance of 18650 Pack

Of course there is no typical voltage for all 18650 packs. I am just asking if there are typical values for certain packs (like 13s5p mj1 or 14s5p GA or what ever) to see if it is normal that the internal resistance is 50% higher than the calculated value (without resistance of connections inside th...
by hias9
Dec 03 2020 3:20am
Forum: Battery Technology
Topic: Typical Internal Resistance of 18650 Pack
Replies: 16
Views: 799

Re: Typical Internal Resistance of 18650 Pack

My controller logs battery current and battery voltage. I am simply calculating it resistance = voltage sag divided by current. The 38mOhm was probably AC resistance. But shouldnt DC resistance be lower? Battery temperature was about 15 degrees Celsius. There was no significant difference between 90...
by hias9
Dec 02 2020 11:46pm
Forum: Battery Technology
Topic: Typical Internal Resistance of 18650 Pack
Replies: 16
Views: 799

Typical Internal Resistance of 18650 Pack

When calculating internal resistance of my 14S10P Sanyo GA pack based on voltage drop it is around 90-95mOhm. I read that the internal resistance of one GA cell should be <38mOhms, so I expected the internal resistance to be 14/10*38mOhm + 5mOhm (wire resistance) = <58mOhm. Are the 35mOhms caused by...
by hias9
Nov 23 2020 12:34am
Forum: EBike General Discussion
Topic: Battery Crash Protection
Replies: 13
Views: 532

Re: Battery Crash Protection

Do you think a sandwich (plate of hard material - foam - plate of hard material) has any advantages over just hard material outside and foam inside?
by hias9
Nov 22 2020 11:31pm
Forum: EBike Technical
Topic: Hub Motor out of true
Replies: 6
Views: 221

Re: Hub Motor out of true

No, I use a 3-arm gear puller
by hias9
Nov 22 2020 10:23pm
Forum: EBike Technical
Topic: Hub Motor out of true
Replies: 6
Views: 221

Re: Hub Motor out of true

It is "buckled" (out of true). Maybe 1mm at the spoke flange. It sits perfect inside the dropouts and is fixed by torque arms on both sides (connected to IS2000 mount on the left, and to a thread I cut into the frame on the right) The cover screws are only M4, so they should only be tighte...
by hias9
Nov 22 2020 9:13pm
Forum: EBike Technical
Topic: Hub Motor out of true
Replies: 6
Views: 221

Re: Hub Motor out of true

The problem is not the brake disc. The motor itself is not turning round, which caused the rim, the brake disc and the flywheel to be out of true. I checked it by holding the end of a zip tie to the spoke flange on the side where I have spoke elbows inside. I put the Statorade directly onto the roto...
by hias9
Nov 22 2020 1:56pm
Forum: EBike Technical
Topic: Hub Motor out of true
Replies: 6
Views: 221

Hub Motor out of true

On a 45mm magnet 3kw motor (very similar to mxus 3k), I have yesterday removed the right cover, added some more Statorade, and then reinstalled the right cover with silicone sealant. After that the motor was a bit out of true. Less than a millimeter on the spoke flange, but I had to retrue the rim a...
by hias9
Nov 22 2020 4:32am
Forum: EBike General Discussion
Topic: Battery Crash Protection
Replies: 13
Views: 532

Re: Battery Crash Protection

The pack is about 68mm wide. At the moment plus 2x 6mm yoga mat on each side. I don‘t want more than 4mm on each side. With the yoga mats knees are almost rubbing on the frame bag. I don’t do hard offroad riding with this bike. The bag is secure while riding (secured by about 10 velcros). When crash...
by hias9
Nov 21 2020 4:05pm
Forum: EBike General Discussion
Topic: Battery Crash Protection
Replies: 13
Views: 532

Re: Battery Crash Protection

Carbon Fibre plate. sorry
by hias9
Nov 21 2020 1:58pm
Forum: EBike General Discussion
Topic: Battery Crash Protection
Replies: 13
Views: 532

Battery Crash Protection

On one bike I have a large triangle battery inside a frame bag. Crash protection should be light and not too wide, so knees won't touch the frame bag while pedaling. At the moment I am using a 6mm yoga mat on both sides. Knees don't rub on the frame bag while pedaling, but it is really close. And th...
by hias9
Nov 21 2020 12:41pm
Forum: EBike General Discussion
Topic: Alternative to Domino Throttle
Replies: 3
Views: 314

Re: Alternative to Domino Throttle

I have used two brass thread inserts to repair the thread. Quite simple and now and it is as tight on the handlebar is it should.
Just need to drill out the holes and melt the thread inserts in with a soldering iron (remove all tin from the tip before)
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