Search found 2888 matches

by madin88
Jan 26 2020 3:33pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 240
Views: 20683

Re: Li-ion cells cycle ageing

To get a true representation of battery ageing or wearout, the tests must be run with complete batteries ... just as they would be in the planned application. Similarly, extrapolating the performance of the whole population of batteries from a sample of one [cell] can also give unreliable results a...
by madin88
Jan 26 2020 8:30am
Forum: Motor Technology
Topic: Revolt RV-series motor review and comparisons
Replies: 283
Views: 26493

Re: Revolt RV-series motor review and comparisons

...Maybe I should stop spreading the myth that peak efficiency is when copper and iron losses are equal... Why are you calling it a myth? As long as you add "for a given voltage" it's true AFAIC and I proved it to myself with a quick bit of trial and error using the spreadsheet. Thanks for pointing...
by madin88
Jan 23 2020 4:43am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 240
Views: 20683

Re: Li-ion cells cycle ageing

@ eMark You need to compare either rest voltage with rest voltage, or load voltage with load voltage to get an apples to apples comparison. Also during charge the battery will be under "load", therefore the voltage will be higher as it would be at rest. When looking at red (1A) curve from following ...
by madin88
Jan 23 2020 4:22am
Forum: Motor Technology
Topic: Revolt RV-series motor review and comparisons
Replies: 283
Views: 26493

Re: Revolt RV-160-SH update

82v x 10 amps = 820 watts (phase amps) 82v x 6 amps = 492 watts (battery amps) I listed both in case people cared. It's not an error, it's being thorough. If you want to convert 82V DC into 3-phase AC which is what the controller is doing, it cannot be 82V RMS on the output even at 100% PWM or WOT ...
by madin88
Jan 22 2020 5:14am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 240
Views: 20683

Re: Li-ion cells cycle ageing

Yes, aware of that heresay ... sooo welcoming a worthwhile challenge had decided to build a DIY Vruzend 10S5P battery with 30Q cells to track cycle life longevity and any self discharge. FWIW the new 30Q cells are 141 not 138. Will keep a close eye on any resting self-discharge and will send you a ...
by madin88
Jan 21 2020 2:40pm
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 895
Views: 63703

Re: APL's DIY axial-flux motor

Well, we'll get back to that later, I have a lot of research to do on back iron thickness. It depends on so many things, magnet thickness & T value, delivered current, magnet spacing, and air gap. For now I'll just stick with adding steel rings to the outside, and checking performance. If there is ...
by madin88
Jan 21 2020 2:05pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 240
Views: 20683

Re: Li-ion cells cycle ageing

Thanks for your effort. Nice to see that LG perform so good. What about doing another test with M36 or MJ1 between 4,2 and 3V? I would like to see what happens then with cycle life. Is it possible that the Samsung 30Q (LNM) actually has decent-to-good cycle life longevity when it's ebiking applicati...
by madin88
Jan 21 2020 11:36am
Forum: E-Bike Build Threads / Photos & Video
Topic: Klein Mantra rebuild / TSDZ2
Replies: 8
Views: 314

Re: Klein Mantra rebuild / TSDZ2

This is how the cells will be connected. If you got any input or ideas for improvement, please let me know: Looks fine :thumb: Don't go centrelock. They are a lot more expensive and no cheap alternatives. I would easily choose a different hub if I had to, proprietary standards suck. I already order...
by madin88
Jan 21 2020 11:09am
Forum: Items for Sale - New
Topic: Nucular electronics - complete kit for ev! [beta]
Replies: 1099
Views: 104308

Re: Nucular electronics - complete kit for ev! [beta]

If I had the constant power setting I would have traveled 3m and then I would have come back on foot pushing my 400kg cart for 997m. :lol: I suppose the controller will reduce power either way when the voltage drops to the value you entered, so you would have more or less the same time to bring you...
by madin88
Jan 19 2020 5:53pm
Forum: Motor Technology
Topic: Winding Question: does STAR make more torque than DELTA, even with adjusted phase current?
Replies: 16
Views: 738

Re: Winding Question: does STAR make more torque than DELTA, even with adjusted phase current?

I have some papers showing max efficiency is when controller and BEMF waveform match - this makes me wonder if there are high-end three-phase square wave controllers, otherwise they’d lose some efficiency right there due to the imbalance. Wasn't it Lebowski who said this? Yes, the waveform of the o...
by madin88
Jan 19 2020 5:16pm
Forum: General Discussion
Topic: What's with this censoring nonsense happening on the forum?
Replies: 81
Views: 4438

Re: What's with this censoring nonsense happening on the forum?

The ES forum is known for beeing a source of knowledge for almost everything around e-bikes and electric vehicles, be it motors, controllers, BMS or anything else thats related to this. I for myself have learned a lot here and probabaly other members will learn from here too in future, thats why i h...
by madin88
Jan 19 2020 1:50pm
Forum: Motor Technology
Topic: Winding Question: does STAR make more torque than DELTA, even with adjusted phase current?
Replies: 16
Views: 738

Re: Winding Question: does STAR make more torque than DELTA, even with adjusted phase current?

Lets take a closer look at number 4 and compare the currents which flow in STAR and DELTA. Phase 1 and 2 are engergized with the maximum current while phase 3 is open (at 0V as it is crossing the x-axis). Forget the BEMF thing as our motor is at stall or spinning at low RPM. in STAR: winding1 = 200A...
by madin88
Jan 19 2020 12:51pm
Forum: Motor Technology
Topic: Winding Question: does STAR make more torque than DELTA, even with adjusted phase current?
Replies: 16
Views: 738

Re: Winding Question: does STAR make more torque than DELTA, even with adjusted phase current?

I did some more research and have the meaning that even with 3-phase sinewave, there is also quasi one phase open for a very short time (doing nothing), and it is interesting that this happens exactly at the moment when the other two phases see the highest current and probably also producing the mos...
by madin88
Jan 19 2020 9:45am
Forum: Motor Technology
Topic: QS 3000w midmotor
Replies: 447
Views: 48386

Re: QS 3000w midmotor

edit: The airgap seems to be quite narrow, that's nice Yep thats good for torque, but not so good for iron losses. It’s at 12.5A / 72V on my motor, don’t know exact voltage when i tried it. kv60 without flux Thats around 900W which i find is a bit on the high side for ~4000RPM on a motor like this.
by madin88
Jan 19 2020 9:35am
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 4397
Views: 414211

Re: Sur-Ron - New Mid drive Bike

Merlin wrote:
Jan 19 2020 8:41am
with the new aluminimum case =)
:thumb:
18650 cells or which size, and does it fit without doing anything on the frame (like filing and grinding)?
by madin88
Jan 19 2020 8:57am
Forum: Motor Technology
Topic: Winding Question: does STAR make more torque than DELTA, even with adjusted phase current?
Replies: 16
Views: 738

Re: Winding Question: does STAR make more torque than DELTA, even with adjusted phase current?

But if the windings remain below saturation, the torque should be the same at the adjusted phase current (x1,73 in delta). In fact in delta the phase current is not divided in 1/3 - 2/3 manner between the windings, because all the 3 phase currents are controlled as per the 3-phase sine waveforms. I...
by madin88
Jan 19 2020 8:37am
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 4397
Views: 414211

Re: Sur-Ron - New Mid drive Bike

Merlin wrote:
Jan 18 2020 7:08pm
20s14p - 3Kwh - is on the way :D
I would like to know more about that battery. :)
Is it 14p inside the silver case (looks selfmade?), or with the add-on bag?
by madin88
Jan 19 2020 8:06am
Forum: Items for Sale - New
Topic: Nucular electronics - complete kit for ev! [beta]
Replies: 1099
Views: 104308

Re: Nucular electronics - complete kit for ev! [beta]

But it’s not power matching aV*2bA to 2aV*bA that’s done. Why not? Lets take as example a setup with 20s battery which is set up as following: max batt amps: 100A max phase amps: 300A max speed: 80kmh with above settings, the max power at 100% SOC would be 100x84V = 8400W, and at lower SOC like 70V...
by madin88
Jan 19 2020 6:12am
Forum: Items for Sale - New
Topic: Nucular electronics - complete kit for ev! [beta]
Replies: 1099
Views: 104308

Re: Nucular electronics - complete kit for ev! [beta]

iam so happy that the important guy knows what i mean (vasiliy) :D :mrgreen: :lol: It makes perfectly sense, especially if you have speed limits set (or enough RPM in reserve), you hardly would notice a difference in acceleration or power over the entire state of charge. The only not so nice thing ...
by madin88
Jan 16 2020 5:54am
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 895
Views: 63703

Re: APL's DIY axial-flux motor

Heres a quick modification on the last drawing that shows what it might look like, sort of,.. I had a hard time figuring out how to show it. The most optimized design would be a V-groove that starts with 0mm in the middle of the magnet and up to 1/3 where it ends, but that would be a lot of effort ...
by madin88
Jan 15 2020 6:42am
Forum: E-Bike Reviews & Testing
Topic: Epic 7kw+ 12 fet controller...or there abouts :)
Replies: 139
Views: 15346

Re: Epic 7kw+ 12 fet controller...or there abouts :)

Looks like it blew one trace off the board. It's remotely possible the trace blew first then things cascaded. It could have happended that way. When i repaird my two 12F back then, i noticed the issue and beefed up those traces. They supply batt minus to one of the two low-side FET's so it has to c...
by madin88
Jan 14 2020 8:52am
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 895
Views: 63703

Re: APL's DIY axial-flux motor

Another idea I had for the rotor was to use a one piece tapered shape for minimum weight, and a more organic look. Still need to know how thick though, and it would be more machining, so maybe not on this motor,.. but we'll see. Taper matches the trapezoid taper. Looks good :thumb: Just to clarify ...
by madin88
Jan 13 2020 2:12pm
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 895
Views: 63703

Re: APL's DIY axial-flux motor

But I could make the back iron a 'little' thicker without too much design change. I don't know how much fudge factor I have with thickness,..as a 'rule of thumb' formula. It depends on the magnet grade like N35 or N50 and the fact that steel starts to saturate at around 1.6T, but only a simulation ...
by madin88
Jan 12 2020 9:46am
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 4397
Views: 414211

Re: Sur-Ron - New Mid drive Bike

Your controller may get a little hotter stepping down to 30% of OCV than it would with a lower pack voltage (ie stepping down to 60% OCV - but these losses are minimal anyway. This is also the key point - your controller is stepping down the voltage from your pack to your motor in order to control ...
by madin88
Jan 09 2020 3:17pm
Forum: Battery Technology
Topic: Best 18650 cell for 3p 18A max
Replies: 24
Views: 685

Re: Best 18650 cell for 3p 18A max

6A per cell is pretty much in the middle because both, high C or high mAh cells, will give you similar range. The high mAh cells have more V sag, but make up for it with more mAh, while the high current cells have more V and lower mAh, so usable Wh will be quite similar. What would speak for high C ...