Search found 69 matches

by kd8cgo
Jul 21, 2015 4:55 am
Forum: General Discussion
Topic: Moving - to WHERE?
Replies: 91
Views: 5807

Re: Moving - to WHERE?

Technomadia is awesome - they up-sized over the years, but still such a cool lifestyle to me. Nomadism just has a certain ring to it. I still would want a place to return to, I think. And I would want that place to be within sight, sound, or smell of no other human being for miles . Nothing but raw ...
by kd8cgo
Jul 20, 2015 9:14 pm
Forum: Battery Technology
Topic: How does Tesla balance cells, disconnect dead cells, etc?
Replies: 5
Views: 582

Re: How does Tesla balance cells, disconnect dead cells, etc

I'm not sure on the thread... This is a very basic document with a high level overview of the Roadster packs. I'm sure there is more out there, I just don't have anything else off hand.
by kd8cgo
Jul 20, 2015 8:47 pm
Forum: Battery Technology
Topic: Bottom balancing?
Replies: 479
Views: 16692

Re: LITHIUM BALANCE? Is It Top, Middle, or Bottom?

I'm just waiting for the ladder logic source code to come out for the A123 systems stuff, wb9k. I'd love to see who you consulted with on your manufacturing. Allen Bradley, Siemens? :wink: I've got some friends at Siemens so I can get you some discounts maybe. Next time I see them I'll ask them abou...
by kd8cgo
Jul 20, 2015 7:56 pm
Forum: Battery Technology
Topic: Bottom balancing?
Replies: 479
Views: 16692

Re: LITHIUM BALANCE? Is It Top, Middle, or Bottom?

Man dnmun, I swear your posts are the most negative vitriolic stuff I ever read here from a long time member sometimes! I hope you're more pleasant in person! :shock: That being said, I don't find the technical proficiency on display inspiring, SunKing. So far all you have are anecdotes, and profess...
by kd8cgo
Jul 20, 2015 3:08 pm
Forum: Battery Technology
Topic: Bottom balancing?
Replies: 479
Views: 16692

Re: LITHIUM BALANCE? Is It Top, Middle, or Bottom?

It's a good point, could be battery monitoring system and/or battery management system. My 18650 packs handle LVC/HVC and balancing functions, which is about all you can ask for besides potentially data logging for trend analysis, which I'd love to have if troubleshooting were ever required - a lot ...
by kd8cgo
Jul 20, 2015 12:37 pm
Forum: Battery Technology
Topic: Bottom balancing?
Replies: 479
Views: 16692

Re: LITHIUM BALANCE? Is It Top, Middle, or Bottom?

The simple fact is SunKing, you're preaching to the choir. Many hobby-level project here don't use a BMS, especially when they are using LiPo. It's a convenience feature for people that saves time and effort. The people who don't use a BMS, use a balancing charger to set up their pack 99% of the tim...
by kd8cgo
Jul 19, 2015 2:48 pm
Forum: Battery Technology
Topic: Bottom balancing?
Replies: 479
Views: 16692

Re: LITHIUM BALANCE? Is It Top, Middle, or Bottom?

As LFP discharges the internal resistance goes down thus increasing efficiency. Internal resistance is essentially FLAT from 100 to 0% SOC AC Impedance Based State of Charge Dynamic Modeling of a LiFePO4 Battery for Hybrid Electric Vehicle Applications Please note from pp.5 (original pp.471) Figure...
by kd8cgo
Jul 18, 2015 9:53 pm
Forum: General Discussion
Topic: MOVIE NITE
Replies: 310
Views: 21508

Re: MOVIE NITE

I really like Firefly/Serenity. The good stuff always seems to get chucked!

Here's a scene from one I really like:
Network (1976)

by kd8cgo
Jul 17, 2015 9:05 pm
Forum: Large EV General Discussion
Topic: Miles ZX40ST refurb project
Replies: 71
Views: 7772

Re: Miles ZX40ST refurb project

wb9k wrote:EDIT: Never mind, I know where you are ;-)

73,
Damn sneaky hammers! :P 73, Indeed!
by kd8cgo
Jul 17, 2015 6:33 pm
Forum: General Discussion
Topic: Model M - Tesla concept going two wheels
Replies: 2
Views: 292

Re: Model M - Tesla concept going two wheels

Alright, slapping the Tesla name on an (admitted cool) rendering/concept art is just down-right RUDE! You had me excited for a second...
by kd8cgo
Jul 17, 2015 4:30 pm
Forum: Large EV General Discussion
Topic: Miles ZX40ST refurb project
Replies: 71
Views: 7772

Re: Miles ZX40ST refurb project

Excellent news! For the mount, you can use two pieces of C-channel, or rectangular tube to get the "height" offset from the motor surface for your bearing. A plate or flat bar bridging the surface gives you a location to mount your flange ears. Depending on the total height, some triangulation would...
by kd8cgo
Jul 17, 2015 8:23 am
Forum: E-Bike Technical
Topic: Definitive Tests on the Heating and Cooling of Hub Motors
Replies: 1964
Views: 249082

Re: Definitive Tests on the Heating and Cooling of Hub Motor

I think you mean conduction not convection, Haha, yes, this was very much a pre-coffee post! Thanks for this breakdown on the solid metals conduction, it's really helping wrap my head around! So If I want to model a MXUS motor with a slightly different stator hub and a large bearing, I can use a hu...
by kd8cgo
Jul 17, 2015 6:52 am
Forum: Motor Technology
Topic: build your very own Lebowski controller !
Replies: 293
Views: 35792

Re: build your very own Lebowski controller !

Wow, I have missed this DIY controller thing, and I find it is AMAZING! I have to get started on a few of these. I see it is closed source/proprietary but I am not totally familiar with this PIC programming. If I want to program the chip does the initial flash need to be done with a programmer like ...
by kd8cgo
Jul 17, 2015 5:03 am
Forum: E-Bike Technical
Topic: Definitive Tests on the Heating and Cooling of Hub Motors
Replies: 1964
Views: 249082

Re: Definitive Tests on the Heating and Cooling of Hub Motor

I'm really liking this "science" stuff being applied to hub motors with this wind tunnel business! It's coming together well! Have you considered a squirrel cage instead of an axial fan to save decibels? I've not seen a cage on a wind tunnel before, maybe the 90' turn from the input flow to the outp...
by kd8cgo
Jul 16, 2015 5:12 pm
Forum: Battery Technology
Topic: Cycle Satiator - help me please!!
Replies: 10
Views: 670

Re: Cycle Satiator - help me please!!

You need to figure out your charge % vs. pack voltage. An easy way is the ebikes.ca Charge Simulator . For your battery, you can assume the following voltage vs. what percent of the total capacity is left in the battery: Cell V Pack V Percent Available AH --------------------------------------------...
by kd8cgo
Jul 16, 2015 4:34 am
Forum: E-Bike General Discussion
Topic: Down under ID?
Replies: 6
Views: 332

Re: Down under ID?

The US constitution says you have the right to remain silent, but the supreme court says you must have an id card on you..... :? The SCOTUS says you must provide your full legal name if stopped by an officer (in a state with a stop and identify statute) with reasonable suspicion that you have commi...
by kd8cgo
Jul 16, 2015 1:01 am
Forum: Items for Sale - New
Topic: Samsung INR 18650 25r 48v and 52v battery packs for sale
Replies: 99
Views: 10040

Re: Samsung INR 18650 25r 48v and 52v battery packs for sa

krunchi wrote:Do you ship to Australia?
Green Machine wrote:Right now we arent shipping batteries internationally..... we can ship any other product but not batteries.
Nothing outside the US for now it looks like.
by kd8cgo
Jul 15, 2015 9:35 pm
Forum: E-Bike Non-hub Motor Drives
Topic: Spot Honey Badger e-bike Build
Replies: 19
Views: 3706

Re: Spot Honey Badger e-bike Build

Wow. I really love this! Dare I ask how much something like this sets you back, all in? These components don't look exactly cheap!
by kd8cgo
Jul 15, 2015 9:28 pm
Forum: Items for Sale - New
Topic: Samsung INR 18650 25r 48v and 52v battery packs for sale
Replies: 99
Views: 10040

Re: Samsung INR 18650 25r 48v and 52v battery packs for sa

Have you guys worked out shipping notifications or order status inquiries yet? I didn't get anything yet for tracking, but I was wondering if your cart system handles that kind of thing, or if it's got to be manual for now. I suppose it depends on the carrier(s) you use as well!
by kd8cgo
Jul 15, 2015 9:17 pm
Forum: E-Bike Technical
Topic: Definitive Tests on the Heating and Cooling of Hub Motors
Replies: 1964
Views: 249082

Re: Definitive Tests on the Heating and Cooling of Hub Motor

I personally think we've just invented the "sliced bread" of hub motors! Good job! :D
by kd8cgo
Jul 15, 2015 4:57 pm
Forum: E-Bike Technical
Topic: Definitive Tests on the Heating and Cooling of Hub Motors
Replies: 1964
Views: 249082

Re: Definitive Tests on the Heating and Cooling of Hub Motor

Lol yeah, the axle would remain steel, but the main design change is to move the bearing from a small one on the axle to a much, much larger one that allows for an aluminum heat sink to poke through, around the axle. The outer surface of that aluminum heat sink would then be where the bearing/bearin...
by kd8cgo
Jul 15, 2015 4:46 pm
Forum: E-Bike Technical
Topic: Definitive Tests on the Heating and Cooling of Hub Motors
Replies: 1964
Views: 249082

Re: Definitive Tests on the Heating and Cooling of Hub Motor

No, the fins would actually be attached to the stator/axle and not rotate with the wheel. Speedmd is saying that if you run a duct system along the left side, it serves double duty as a rotor cooling shroud as well. So you get a motor bonus and a brake bonus by ducting air across that side of the mo...
by kd8cgo
Jul 15, 2015 3:13 pm
Forum: E-Bike Technical
Topic: Definitive Tests on the Heating and Cooling of Hub Motors
Replies: 1964
Views: 249082

Re: Definitive Tests on the Heating and Cooling of Hub Motor

One of those with a pin fin heatsink filling nearly the entire internal area between the axle and the rotor would look cool as hell! Like one of these: http://m.c.lnkd.licdn.com/mpr/mpr/p/6/005/059/0ac/12a77e1.jpg They would be a nice option because the pins could be manufactured proud of the dropou...
by kd8cgo
Jul 15, 2015 3:00 am
Forum: Large EV General Discussion
Topic: Miles ZX40ST refurb project
Replies: 71
Views: 7772

Re: Miles ZX40ST refurb project

Complex systems are... complex! I guess that's why they have teams for this kind of thing normally, since there are tons, and tons, and tons of things to consider in unison. I've known a few guys to catch the stuff on the other side of a vehicle weld on fire - interior panels, insulation, oil in the...
by kd8cgo
Jul 15, 2015 1:59 am
Forum: E-Bike Technical
Topic: Definitive Tests on the Heating and Cooling of Hub Motors
Replies: 1964
Views: 249082

Re: Definitive Tests on the Heating and Cooling of Hub Motor

I've always thought large diameter bearing on one side was a huge potential for cooling options. The problem is the solution is straight forward on the front motor, and needs a little more thought for a rear. I know they make scooter and atv rotors in the 160-200mm range that have larger ID's than b...