Search found 13692 matches

by liveforphysics
Apr 25 2019 7:00pm
Forum: Battery Technology
Topic: DIY copper/nickel buses for 18650's
Replies: 10
Views: 298

Re: DIY copper/nickel buses for 18650's

I just remembered that we're not supposed to spot-weld onto the center of the negative ends. Here's my latest version...the red dots are the proposed spot-welds. BatterySpotweldTab1.png Getting warmer (close!) Now think about the current density map through your conductor. How do those pair of line...
by liveforphysics
Apr 25 2019 6:53pm
Forum: Battery Technology
Topic: Air gap between cells
Replies: 14
Views: 167

Re: Air gap between cells

Which then eliminates all air gaps? Are there light potting compounds with thermal conductivity greater than air? No possibility of using convection / active ventilation then right? If you're going to use active ventilation, then you need to have a solution to deal with what happens to the dew/humi...
by liveforphysics
Apr 25 2019 6:08pm
Forum: Battery Technology
Topic: Air gap between cells
Replies: 14
Views: 167

Re: Air gap between cells

So you think even the thin plastic type is significantly insulating? Just haven't seen many setups with bare metal cylinder walls You can make a good pack that has shrink on the cells if you fully encapsulate the cell/shrink assembly, but at that point the shrink is only decorative for your pack an...
by liveforphysics
Apr 25 2019 6:04pm
Forum: Battery Technology
Topic: Air gap between cells
Replies: 14
Views: 167

Re: Air gap between cells

Shrink creeps steadily under pressure and relative motion. Before it creeps out of insulating contact points for you, it serves as a vapor/humidity trap to accelerate the cell corroding. Real mechanical structure for the cells to control spacing and relieve all mechanical stress from interconnect as...
by liveforphysics
Apr 25 2019 5:20pm
Forum: Battery Technology
Topic: Air gap between cells
Replies: 14
Views: 167

Re: Air gap between cells

Hi, Do the cells manufacturers Sony, Samsung and LG recommend any minimum air gap between cells in a battery pack? I have checked a couples of data sheets and I couldn't find anything. Thanks Unless you've got some amazing position fixture for your cells, 2mm minimum (and ideally no cell wrappers) ...
by liveforphysics
Apr 23 2019 1:59pm
Forum: Motor Technology
Topic: Hubmonster teardown
Replies: 12
Views: 512

Re: Hubmonster teardown

Looks like a really well designed hubmotor! Im impressed!
by liveforphysics
Apr 23 2019 1:28pm
Forum: Motor Technology
Topic: BESC - beefed up VESC motor controller for high power ebikes
Replies: 81
Views: 3993

Re: BESC - beefed up VESC motor controller for high power ebikes

I charge to 4.35V/cell if I think it's questionable if I've got enough energy to make the ride, or at the racetrack where every extra watt of output is precious.
For a normal ride, I charge to 4.05V/cell. I would still want a controller that supports charging to 4.35V/cell though.
by liveforphysics
Apr 22 2019 11:27am
Forum: E-Vehicles General Discussion
Topic: ICE vs Electric Motor Transmissions
Replies: 74
Views: 2149

Re: ICE vs Electric Motor Transmissions

It's not a torque converter, its pure loss like a linear voltage regulator. A torque converter uses acceleration of mass of fluid changing the radius of the fins its pushing against as its slung out. This lets it actually trade constant speed engine RPM for increased torque output. A top fuel car ha...
by liveforphysics
Apr 22 2019 11:09am
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 3459
Views: 225526

Re: Sur-Ron - New Mid drive Bike

Im loving the aftermarket support building for Sur Rons! So many beautiful high performance Sur Rons! I love it!
by liveforphysics
Apr 19 2019 8:36pm
Forum: Items for Sale - New
Topic: PV NextGen Controller FOC compact 150v 22kw Max - $499
Replies: 23
Views: 929

Re: PV NextGen Controller FOC compact 150v 22kw Max - $499

Field weakening takes away from efficiencies. There is a reason high power vehicles run higher voltages. This is not to say 100v or even 60v mosfets can’t be put in. Not sure what kind of hassling with shunts you have in mind. There are no shunts involved here. Only high precision current sensors. ...
by liveforphysics
Apr 19 2019 7:15pm
Forum: Battery Technology
Topic: DIY copper/nickel buses for 18650's
Replies: 10
Views: 298

Re: DIY copper/nickel buses for 18650's

I think it makes sense and is more simple than trying to get high current out of nickel busing alone.
by liveforphysics
Apr 19 2019 6:32pm
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: John's HubMonster powered MadAss hits 182kph (113mph)
Replies: 3
Views: 179

Re: John's HubMonster powered MadAss hits 182kph (113mph)

Beautiful beastly machine my friend!!! Woot!!!

What an accomplishment to hit those speeds! :bigthumb: :bolt: :mrgreen: :twisted: 8)
by liveforphysics
Apr 18 2019 1:22pm
Forum: Battery Technology
Topic: How do I test a BMS to make sure its working?
Replies: 36
Views: 496

Re: How do I test a BMS to make sure its working?

Congrats on one of the most sketchy DIY builds I've seen.
by liveforphysics
Apr 16 2019 4:53pm
Forum: Battery Technology
Topic: Experience with Frogzskins for venting?
Replies: 6
Views: 158

Re: Experience with Frogzskins for venting?

Materials that pass vapor (humidity) but seal against liquid water tend to work like 1 way traps to steadily accumulate condensation inside a device.
by liveforphysics
Apr 15 2019 2:43am
Forum: Motor Technology
Topic: Scott Drive SD300 (300+KW)
Replies: 6
Views: 418

Re: Scott Drive SD300 (300+KW)

Nice controller my friend!
by liveforphysics
Apr 14 2019 6:28pm
Forum: E-Bike Technical
Topic: Beware of FerroFluid!
Replies: 13
Views: 776

Re: Beware of FerroFluid!

Has anyone tested if it can absorb enough water over time to gain electrolyte-esque behavior? Maybe humidity can make the micro particles clump into macro particles that aren't insulated from eachother? The base oils are the same oil bases used by Nissan and GM and Tesla inside motors for cooling an...
by liveforphysics
Apr 12 2019 4:46pm
Forum: EV Business World
Topic: Tesla Model 3
Replies: 862
Views: 49947

Re: Tesla Model 3

I won't rule tesla out they could branch out just like toyota has with Lexus and turn the model s x y and 3 into a luxury chain and move a new brand at the cheaper end of the market utilizing components from the brother brand but with a raspi for the infotainment system and cut throat self driving ...
by liveforphysics
Apr 12 2019 1:41pm
Forum: EV Business World
Topic: Tesla Model 3
Replies: 862
Views: 49947

Re: Tesla Model 3

Maybe I just notice them more, but it seems like I'm seeing more Tesla's than Toyota's on my daily commute here in California. I'm sure there's hundreds of Toyota's registered for every 1 Tesla, but once someone has a Tesla that Toyota's going to be a driveway ornament rather than something someone ...
by liveforphysics
Apr 12 2019 12:05am
Forum: Motor Technology
Topic: VESC-controller: Axiom hardware released!
Replies: 278
Views: 39465

Re: VESC-controller: Axiom hardware released!

So awesome to see a serious controller option enter the EV hotrod scene!!!

You guys are amazing!!!
by liveforphysics
Apr 10 2019 12:52am
Forum: E-Scooter and Motorcycle General Discussion
Topic: Petersen Museum Electric Motorcycles Exhibit
Replies: 13
Views: 253

Re: Petersen Museum Electric Motorcycles Exhibit

So awesome! Im going to have to visit that exhibit! Thank you for sharing pictures!
by liveforphysics
Apr 09 2019 9:56pm
Forum: Battery Technology
Topic: Am wanting a 10A continuous 18650-21700 cell
Replies: 21
Views: 458

Re: Am wanting a 10A continuous 18650-21700 cell

LG HG2
Samsung 30Q

Or if you can accept more sag, LG MJ1 works too.
by liveforphysics
Apr 09 2019 7:04pm
Forum: E-Bike General Discussion
Topic: 21kw+ QS273 won't outrun a 250cc?
Replies: 38
Views: 1147

Re: 21kw+ QS273 won't outrun a 250cc?

mobipus 72200, asi bac8000 controllers i suspect will give better results(just from trawling,not personal experience yet) me i like smaller light bikes with good power/weight ratio over big heavy tanks...going over 100 on highway gets boring fast anyway. id be maybe ditching the kelly, changing bat...
by liveforphysics
Apr 09 2019 6:55pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 3459
Views: 225526

Re: Sur-Ron - New Mid drive Bike

How much price difference there is between BAC-4000 and BAC-8000? Also, would BAC-4000 be enough for 8 KW power and to reach 100 km/h? Also, I'm not sure about the fit, since the length of the BAC-8000 seems to suggest that it can't fit very well. A e-bikes have the ASI Bac8000 controller fitted pr...
by liveforphysics
Apr 08 2019 10:17pm
Forum: Polls & Surveys
Topic: If you could do something entrepreneurial in the EV industry,what would you do?
Replies: 6
Views: 313

Re: If you could do something entrepreneurial in the EV industry,what would you do?

Develop a production friendly and cost friendly solid electrolyte.

Develop a recycling process that can re-use the waste of worn out EV packs in a cost effective and environmentally friendly way.