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by liveforphysics
Jan 22 2019 6:12am
Forum: Battery Technology
Topic: Toyota and Panasonic form huge battery R&D & production partnership
Replies: 11
Views: 287

Re: Toyota and Panasonic form huge battery R&D & production partnership

Table salt on a conventional 18650 guts won't do it, but if you pair the right materials, its no physics problem to go way beyond 8Ah, perhaps 80Ah in an 18650, just a materials stability and compatibility problem. I bet when we get upto the $20billion mark in R&D we'll find some breakthrough SS bat...
by liveforphysics
Jan 22 2019 4:38am
Forum: Battery Technology
Topic: Toyota and Panasonic form huge battery R&D & production partnership
Replies: 11
Views: 287

Re: Toyota and Panasonic form huge battery R&D & production partnership

bearing wrote:
Jan 21 2019 11:36am
I think this sounds like a high up corporate decision, and not something sparked from an innovation in a lab.

Lots of manpower and hours will definitely lead to refinement of known technology. But not necessarily lead to innovation.
+1
Bingo.
by liveforphysics
Jan 20 2019 7:20pm
Forum: Battery Technology
Topic: Toyota and Panasonic form huge battery R&D & production partnership
Replies: 11
Views: 287

Re: Toyota and Panasonic form huge battery R&D & production partnership

I bet when we get upto the $20billion mark in R&D we'll find some breakthrough SS battery... its just a matter of time/people/money.... I used to think that was true, but you actually just need someone who figures out a solution that meets the cost/mfg/performance/safety needs no matter where it co...
by liveforphysics
Jan 20 2019 7:02pm
Forum: Large EV General Discussion
Topic: Lightweight AWD Sportscar
Replies: 46
Views: 3604

Re: Lightweight AWD Sportscar

I'm excited for your project. I think you had the right idea the first time with lower voltage. Chademo stations you find in the wild are only 50kW charging, I have 28kW of chargers fitted to my DSR motorcycle (over half a typical DC-fast charge station's power). I tap 4 * J1772 plugs, or 2 Tesla pl...
by liveforphysics
Jan 20 2019 5:34am
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: Suzuki GSX-R e899 K2
Replies: 310
Views: 30918

Re: Suzuki GSX-R e899 K2

As far as I know you own the top speed of any hubmotored 2 wheeler. The highest I ever recorded with my daily rider was 172kph, and it had a bit more since it was still accelerating when I let off the throttle. Plus it wasn't at full charge. My newer ebike is running the same motor with a 6% larger...
by liveforphysics
Jan 19 2019 4:59pm
Forum: E-Bike Non-hub Motor Drives
Topic: Modded Sur ron Question
Replies: 8
Views: 274

Re: Modded Sur ron Question

Like I mentioned above, continuous road racing overheats it. It still lasted a couple laps of Laguna Seca hanging with much bigger bikes before that motor melted.
by liveforphysics
Jan 18 2019 7:29pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 3034
Views: 179295

Re: Sur-Ron - New Mid drive Bike

I'm confused, the talk not too long ago was how a belt drive couldn't take the torque or the belt would not handle the power. Now everyone is assuming it will work by slapping on a belt and sprocket? Its no big deal to make a sprocket and install a belt. Why is everyone assuming this will work? I'v...
by liveforphysics
Jan 18 2019 7:18pm
Forum: Battery Technology
Topic: The "thermal management of LiPo" thread!
Replies: 91
Views: 7199

Re: The "thermal management of LiPo" thread!

Stuff looks amazing, but there's $17,000 worth of graphite for a $24,000 battery. I reckon aluminium might be a winner hey... Too bad it's so expensive. The article on tab cooling was interesting. Seems more heat is generated on the tab end because the current density is higher. If the tabs were co...
by liveforphysics
Jan 18 2019 6:03pm
Forum: E-Bike Non-hub Motor Drives
Topic: Modded Sur ron Question
Replies: 8
Views: 274

Re: Modded Sur ron Question

Stock phase leads aren't melting at an power level Ive seen. Dirtbikes with extreme power to weight ratios rarely get a high duty cycle %, and this is what enables the system to live. If you're going to road race it, you can have a high enough duty cycle % to overtemp/cook the motor. Motor cooling e...
by liveforphysics
Jan 18 2019 4:42pm
Forum: E-Bike Technical
Topic: ELECTRIC TRANSMISSION DELTA /WYE and SERIE/PAPALLEL stator
Replies: 652
Views: 97739

Re: ELECTRIC TRANSMISSION DELTA /WYE and SERIE/PAPALLEL stator

If you put the same added mass of the delta/wye switching apparatus towards more mosfet die area in the controller, you end up with higher performance and efficiency. Motors stator/rotor geometry can only be designed for sinus BEMF in either WYE or Delta, but not both. This means if your motor works...
by liveforphysics
Jan 17 2019 2:44pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 3034
Views: 179295

Re: Sur-Ron - New Mid drive Bike

OMG! Drool!!! Beautiful belt conversion! After market, why would surron make that kind of stuff =) With the help from Madin it looks like the next season for Light Bee will be very quiet! I will start offering these quite soon. Dont ask questions yet, full disclosure will be made once we fully test ...
by liveforphysics
Jan 16 2019 3:43am
Forum: General Discussion
Topic: Telescope design; eliminating mirror-support diffraction
Replies: 11
Views: 302

Re: Telescope design; eliminating mirror-support diffraction

https://www.surreynanosystems.com/super-black-coatings/vbx-coatings/vantablack-vbx-2 Spray the mirror supports with that stuff, as well as inside the tube walls, and it will help a bunch. If you don't have reflective surfaces, just blocking light there isn't such a big deal, because any single point...
by liveforphysics
Jan 14 2019 6:33pm
Forum: Battery Technology
Topic: Losing Lipo cells
Replies: 6
Views: 215

Re: Losing Lipo cells

Mechanical stress to the pouches causes cracks in the coating layers that makes self-discharge and gas production in the cells which causes capacity loss when the gas is trapped between layers.

Also, nice bikes! Looks like a blast!
by liveforphysics
Jan 11 2019 6:02pm
Forum: Battery Technology
Topic: VW e-up Li-ion cels
Replies: 42
Views: 5601

Re: VW e-up Li-ion cels

Thanks for sharing my friend. :bolt:
by liveforphysics
Jan 07 2019 3:12pm
Forum: Large EV General Discussion
Topic: Tesla M3 teardown information video - Hallbach Array Motor
Replies: 15
Views: 432

Re: Tesla M3 teardown information video - Hallbach Array Motor

I think the root cause may be that nobody at Monroe seems to grasp basics of EV energy storage or powertrain.
by liveforphysics
Jan 06 2019 3:30pm
Forum: E-Bike Build Threads / Photos & Video
Topic: Toyota Prius A/C Compressor Motorbike: The Bike of IPM Motor Science
Replies: 43
Views: 2965

Re: Toyota Prius A/C Compressor Motorbike: The Bike of IPM Motor Science

I don't know how I missed this thread until now. Wow! You are a rockstar Fpvdude! Lowest effort and lowest performance way to build your IPM tables at higher RPMs may be a woodworking router motor. They should run fine on DC for speed control, and some achieve 18krpm+ More effort, but a second of th...
by liveforphysics
Jan 06 2019 3:11pm
Forum: Motor Technology
Topic: SPM VS IPM Motor - And Field weaken, is it worth it
Replies: 83
Views: 1944

Re: SPM VS IPM Motor - And Field weaken, is it worth it

[quote= If the rotor iron is well designed for leveraging reluctance torque, this will have a ~neutral efficiency impact to use the additional torque. Coming up with that amount you want to deviate from in phase requires a lookup table from characterizing the rotors iron characteristics. Also, take...
by liveforphysics
Jan 06 2019 1:15am
Forum: Motor Technology
Topic: SPM VS IPM Motor - And Field weaken, is it worth it
Replies: 83
Views: 1944

Re: SPM VS IPM Motor - And Field weaken, is it worth it

Dont know about the James Mevey thesis, but I remember that in the early 90ies at the technical university of Eindhoven I had a 'electronic machines' class where the professor told us that making power with a motor comes down to stuffing current into the bemf... That's how you win at power factor o...
by liveforphysics
Jan 04 2019 12:55pm
Forum: Motor Technology
Topic: SPM VS IPM Motor - And Field weaken, is it worth it
Replies: 83
Views: 1944

Re: SPM VS IPM Motor - And Field weaken, is it worth it

I've experienced hundreds of controller faults from various types of field weakening controllers while deep into field weakening and never had that damage anything. This seems odd because the BEMF if you spun the motor up with a drill to that same RPM you faulted at would be above Vdsmax for the mos...
by liveforphysics
Jan 02 2019 3:27am
Forum: Large EV General Discussion
Topic: RIPPY KART
Replies: 28
Views: 1803

Re: RIPPY KART

Beautiful kart my friend!
by liveforphysics
Dec 28 2018 12:50pm
Forum: E-Bike Build Threads / Photos & Video
Topic: 55.2kw bicycle
Replies: 36
Views: 1887

Re: There's a new sheriff in town (new pics on p5)

I want to see it if its 60kW. JohninCR would want to see it too!
by liveforphysics
Dec 23 2018 9:09pm
Forum: Motor Technology
Topic: Brushless motor efficiency
Replies: 25
Views: 1123

Re: Brushless motor efficiency

You're looking at current values in Amps that are around and amp with instrumentation thats +-2amps or more.
by liveforphysics
Dec 21 2018 9:47pm
Forum: Motor Technology
Topic: Brushless motor efficiency
Replies: 25
Views: 1123

Re: Brushless motor efficiency

The current values seen on that software is well inside the current measurement noise expected. If you load it, things will look much different.
by liveforphysics
Dec 21 2018 4:04pm
Forum: Items for Sale - New
Topic: Nucular electronics - complete kit for ev! [beta]
Replies: 364
Views: 27048

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

So can i set FW at rpm-dependent value? Like 20% at 100 rpm 50% at 2000 rpm 80% at 5000 rpm I think you should add 24F estimated specs, price and timing on first post in this thread You want to have mechanically optimized commutation event timing for as long as you have pack voltage > BEMF. For thi...
by liveforphysics
Dec 21 2018 1:58pm
Forum: Motor Technology
Topic: Brushless motor efficiency
Replies: 25
Views: 1123

Re: Brushless motor efficiency

Motor current at no load is just the torque to overcome core losses normally. If you have high motor phase current it means high motor torque output if that current is being applied at the right commutation timing.