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by liveforphysics
Dec 18 2018 10:24pm
Forum: Battery Technology
Topic: Samsung 40T - 35A 21700 Li-ion battery's capacity test
Replies: 1
Views: 24

Re: Samsung 40T - 35A 21700 Li-ion battery's capacity test

I bet you already know this, but no matter how thick you make the end plates, you're still graphing the curve of the cell + pressure interconnect resistance. It would be so easy to just separate the 2 tiny sense wires to touch the can without touching the current drive bus bar so your efforts go int...
by liveforphysics
Dec 17 2018 2:12pm
Forum: E-Vehicles General Discussion
Topic: EV efficiency - new record
Replies: 2
Views: 107

Re: EV efficiency - new record

Im impressed!

Hubmotors FTW!
by liveforphysics
Dec 15 2018 3:23pm
Forum: General Discussion
Topic: Reid Welch Returns (was Re: E.S. Quotable Quotes !)
Replies: 33
Views: 2329

Re: Reid Welch Returns (was Re: E.S. Quotable Quotes !)

Glad you're well Reid! Nice video.

I wear gloves and a full face, both of which get abraided away wreck after wreck until deemed unprotective and replaced. I wreck about 50% of my asphalt track visits, and maybe 500%-1000% average for dirtbiking.
by liveforphysics
Dec 14 2018 5:26pm
Forum: Battery Technology
Topic: Is better to charge the battery only to 80%?
Replies: 18
Views: 532

Re: Is better to charge the battery only to 80%?

The paper you're talking about isn't quite right behavior for modern electrolytes with stabilization additives and modern active material passivity, but useful to show the concepts. If you only use 20% of the capacity, for longest life, only charge to 60%. The battery will probably outlast your inte...
by liveforphysics
Dec 13 2018 6:48pm
Forum: E-Bike Technical
Topic: Mobipus Controllers
Replies: 170
Views: 13666

Re: Mobipus Controllers

It matters for the EV controller application because it's parked in someones garage/home/work place, so it's undesirable to have it fail in corrosion induced fire. Being a motor-controller you may be using for human-life-safety applications like highway traffic, it's important not to randomly fail. ...
by liveforphysics
Dec 13 2018 4:41am
Forum: E-Bike Technical
Topic: Mobipus Controllers
Replies: 170
Views: 13666

Re: Mobipus Controllers

It all depends on your risk if the seal fails. It's another thing that works great 99% of the time when the seal surface interfaces had no defects or debris contamination in assembly. The 1% remainings risk with defects in a motor controller where life safety or fire is at risk, that 1% just got mor...
by liveforphysics
Dec 13 2018 3:13am
Forum: E-Bike Technical
Topic: Mobipus Controllers
Replies: 170
Views: 13666

Re: Mobipus Controllers

In my testing, conformal coating made only a few minutes difference from uncoated in salt-fog testing. Potting entirely prevents the failure. This is because conformal coating leaves the upper sharp geometry edges thin/pinholed. I experimented with multi-layer sprayed conformals, dipped conformals, ...
by liveforphysics
Dec 12 2018 6:19pm
Forum: Large EV General Discussion
Topic: Impending Big big oil and big auto implosion plausible theory (video)
Replies: 22
Views: 414

Re: Impending Big big oil and big auto implosion plausible theory (video)

Whenever the discussion at work turns to EVs, a frequently expressed concern is that an EV can't do everything, but this is usually mentioned by someone who's family has two cars. My wife works close to home, so she is a perfect candidate for an EV. And...when large EV batteries are only cycled in ...
by liveforphysics
Dec 12 2018 4:23pm
Forum: Large EV General Discussion
Topic: What’s stopping Ford and GM from building compelling EV’s?
Replies: 18
Views: 379

Re: What’s stopping Ford and GM from building compelling EV’s?

Always an pleasure and honor to see you Bigmoose. Most of the decision maker position folks at these companies are ICE/Hybrid legacy mindset folks who viewed EVs as the burdensome and financially costly compliance requirement to sell their gas cars into California. If you have two boats, you might d...
by liveforphysics
Dec 12 2018 2:19pm
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: Electric Buell racebike build
Replies: 22
Views: 2627

Re: Electric Buell racebike build

Great job on your build!
by liveforphysics
Dec 12 2018 1:58pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 2794
Views: 162985

Re: Sur-Ron - New Mid drive Bike

Hotroding was all on stock front belt. If the tension is kept snug on them, they handle a boatload of power.
by liveforphysics
Dec 12 2018 4:30am
Forum: Large EV General Discussion
Topic: Impending Big big oil and big auto implosion plausible theory (video)
Replies: 22
Views: 414

Re: Impending Big big oil and big auto implosion plausible theory (video)

Ahh ! OK, so you are looking at using domestic installed battery systems to reduce grid peak loads, as opposed to a public utility installing one large battery to eliminate peaker plants ? Domestic scale storage works for domestic power requirements, and combines synergistically with home rooftop s...
by liveforphysics
Dec 11 2018 3:27pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 2794
Views: 162985

Re: Sur-Ron - New Mid drive Bike

If you run a good chain adjusted right, and adjust the belt right, the ASI controller makes the bike surprisingly a lot more quiet to ride around at low speeds. That tells me if you feed that double reduction drive with low-torque ripple it doesn't experience as much chain resonance. If being more q...
by liveforphysics
Dec 11 2018 3:01am
Forum: Large EV General Discussion
Topic: Impending Big big oil and big auto implosion plausible theory (video)
Replies: 22
Views: 414

Re: Impending Big big oil and big auto implosion plausible theory (video)

*have real skills or find someone how does if you're going to tap your EV battery and tap your home's grid connection and setup a bi-directional inverter. Both sides of that project are high death-to-noob% ratios.
by liveforphysics
Dec 11 2018 2:57am
Forum: Large EV General Discussion
Topic: Impending Big big oil and big auto implosion plausible theory (video)
Replies: 22
Views: 414

Re: Impending Big big oil and big auto implosion plausible theory (video)

It's not even gaming, any urgent demand call you win at your cherry-picking. Leveraging the high peak demand is how the ROI on inefficient peakers workout, otherwise they would never start them. The beauty is, the batteries for replacing the peakers only need to last 30min to an hour to be incredibl...
by liveforphysics
Dec 10 2018 10:06pm
Forum: Large EV General Discussion
Topic: Impending Big big oil and big auto implosion plausible theory (video)
Replies: 22
Views: 414

Re: Impending Big big oil and big auto implosion plausible theory (video)

Eliminating the peaker plants by leveling grid demand is how you get fastest ROI for grid right now. Battery and inverter that replaces peaker plants actually costs less than just the emissions retrofit to existing coal peakers. Meaning that you pay less upfront costs and then don't have to have a d...
by liveforphysics
Dec 10 2018 8:25pm
Forum: Large EV General Discussion
Topic: Impending Big big oil and big auto implosion plausible theory (video)
Replies: 22
Views: 414

Re: Impending Big big oil and big auto implosion plausible theory (video)

The grid storage projects Im involved with all have rapid ROIs of a few years. It's only going to be a shorter ROIs as cell costs and inverter costs keep dropping. Solar farms will never be worse performance or higher cost than they are today, and already slaughter the $/kWh of new coal/natural gas ...
by liveforphysics
Dec 10 2018 8:13pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 2794
Views: 162985

Re: Sur-Ron - New Mid drive Bike

Your wrist takes time to develop throttle control. Once you achieve the wrist control, you can tackle the most gnarly stuff with perfect throttle precision while having a full grip on the bar with both hands. If you go to thumb throttle, you will be capped in performance to only ride things mellow e...
by liveforphysics
Dec 10 2018 2:30pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 2794
Views: 162985

Re: Sur-Ron - New Mid drive Bike

Along with the chain re-tension standard moto maintenance, don't forget to check the primary belt reduction tension as well, as it also relaxes a bit as the belt wears in.
by liveforphysics
Dec 10 2018 2:22pm
Forum: E-Bike Build Threads / Photos & Video
Topic: 60kw bicycle
Replies: 23
Views: 776

Re: 60kw bicycle

The most power I've seen drawn on a dyno from any brushless Kelly controller is ~44kW, and that one was claiming 800amps (running on 28s).

If you swapped to the ASI BAC8000, or a pair of them, you should be able to feed that motor 60kW for bursts plenty long for a bicycles acceleration rate.
by liveforphysics
Dec 09 2018 1:02am
Forum: Battery Technology
Topic: 10 times more energy dense!?
Replies: 1
Views: 233

Re: 10 times more energy dense!?

Plausible. It's never been a physics problem to achieve >3,000Wh/kg, just a materials tech and mfg tech challenge.
by liveforphysics
Dec 07 2018 1:37pm
Forum: Motor Technology
Topic: Some random high speed motor winding machines
Replies: 2
Views: 195

Re: Some random high speed motor winding machines

Is there a machine that will do a fat wire? None here. Fat wire MAY get more fill but recently found that if I adjust the pwm frequency to 30,000 I have no audible noise but it seems to be getting into skin effect territory with a 17 aug wire i read. I want to stay at 30,000. Any experience? PWM fr...
by liveforphysics
Dec 05 2018 8:03pm
Forum: Motor Technology
Topic: 4x less coasting resistance
Replies: 21
Views: 799

Re: 4x less coasting resistance

Magnet back iron and is a small fraction of the total iron core losses (eddy + hysteresis).

Stator iron has a major change in flux density everytime a magnet passes by if you're powering the coil or not powering the coil.
by liveforphysics
Dec 03 2018 9:15pm
Forum: E-Vehicles General Discussion
Topic: Wind and Solar vs Coal, Gasoline, Nuclear
Replies: 2999
Views: 101654

Re: Wind and Solar vs Coal, Gasoline, Nuclear

All non-sustainable systems conclude.

The available options have always been 100% sustainable or inherent auto-extinction.

Whatever perception of hardship may be involved in getting there is a pleasantry to experience over continuing the inevitable destination of non-sustainable energy choices.
by liveforphysics
Dec 03 2018 8:56pm
Forum: Battery Technology
Topic: TrustFire 14500 900mAh - trust or not?
Replies: 10
Views: 434

Re: TrustFire 14500 900mAh - trust or not?

+1 The Ultrafire, Trustfire, Holyfire, Bestfire, Uniquefire, don't make any cells. They run a shrink-wrap line for whatever scrap cells are available if you're getting real cells. This is your best case when buying the xxxFire branded re-shrink cells. If you're getting what they make themselves... h...