Power in Flux

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cmcnall replied to the thread The Juiced Drag bike progress post.
" Based on my experience with my 96V gen 2 Chevy volt packs, you may top out at around 500-515 amps without going parallel. They don't overheat, just that's about max current draw that I have been able to eek out.
If you end up getting more let me know, in either case I have been super impressed with the volt cells and construction in general.

Quote Originally Posted by EVcycle View Post
We finally got to go test. Had a great time, the bike ran flawlessly.

We were running 475 of the 660 available amps..
"

2 Hours Ago

cmcnall replied to the thread Should you have a mechanical, manual pack disconnect?.
" I have an estop with a overcurrent magnetic blowout on the negative side and an LEV200 on the positive side. I will say that when I have accidentally had the bike go into uncontrolled acceleration when messing with settings that e-stop sure is more handy then turning the key to off. Second it is easier to store the bike for the winter. Hit the estop and disconnect the balance connectors and I'm done. "

2 Hours Ago

Stevo clicked Likes for this post: KwSAKI Mk1 (Ex 500) by aggrc

4 Hours Ago

Stevo replied to the thread Should you have a mechanical, manual pack disconnect?.
" I'm glad you saw that because I have used them in the past and I do use one on my fishing kayak! I actually use a Jackson plug, a Gigavac switch, a tethered kill switch controlling an LEV200 contactor, AND an Eaton waterproof circuit breaker for extra redundancy due to salt water being such a great conductor.

I will also add that I am by no means an expert here. I was just joining the discussion/debate and adding my opinion. I do have several years of engineering education under my belt, mostly metallurgical, and completed a TV repair course. I know about degaussing old crt tubes.... the capacitance of which will surely shock the shit right of you, even after being unplugged and turned off for some time. I'm a Rad Tech for career... I chose a different life path way back that coincided more with my life's values of helping others and making life easier for other people. I still have lots to learn but I'm pretty confident in my latest build and the technology that is available to us today. We live in truly exciting times, and changes and advances are coming upon us faster than ever before at any point in history. I am an optimist and prefer to be. My choice!
Sent from my Pixel 2 using Tapatalk "

4 Hours Ago

Ted Dillard replied to the thread Should you have a mechanical, manual pack disconnect?.
" Attachment 8056

I'd rather hear you say, "GEE TED, YOU MAY BE RIGHT!" but like I said, I have a 24 year old son. I have realistic expectations. You did however say "maybe" so I'll take it. "

5 Hours Ago

Stevo replied to the thread Should you have a mechanical, manual pack disconnect?.
" Lol...
I'll tell ya what Ted, if you read in my obituary that I was electrocuted by my diy emc , you can be the first to say "I told ya so!"

Sent from my Pixel 2 using Tapatalk "

5 Hours Ago

Mandres clicked Likes for this post: KwSAKI Mk1 (Ex 500) by aggrc

6 Hours Ago

Ted Dillard replied to the thread Should you have a mechanical, manual pack disconnect?.
" mmmm. Chicken Curry. I'll be right over.

Funny you should mention petcocks. I have never, ever, had a manual petcock leak, and I've ridden for almost as long as Richard. I can't say the same thing about the vacuum shutoffs.

Ultimately it comes down to your trust the technology, your trust of your own design and build skills, the risk, and the price (in all senses of the word) of eliminating that risk. That's where your petcock example breaks down.

Also, as an aside, what's the deal with the sanctimony of build threads these days? In the past, a build thread was to look at what someone was putting together, give them a chance to ask questions about what they needed help with, some constructive critique, stuff like that. You know... discussion. It's not like we spun off into talking about the Red Sox or anything -it is all pertinent to your build... and a fine build it is. "

6 Hours Ago

Stevo replied to the thread Should you have a mechanical, manual pack disconnect?.
" I've got my chicken curry simmering in it's coconut milk now, so I finally have time to add my 2 cents worth.
I'm going to be the forward thinking, lone dissenter here and disagree with all of you!
I say MAYBE, depending on system design and components used. We've come a looooooong way in 10 years! Yes,
I've used the mechanical cutoffs in the past, but.....
The affordability, quality, and availability of today's components are truly amazing.
If you want to compare a shutoff switch to a pitcock valve on an ice motorcycle, that's a good start. My 1996 Honda VFR has a mechanical shutoff on the bottom of the fuel tank, like most ICE motorcycles, but you can't get to it! Its only there for removing the fuel tank. There is, however, a diaphragm on-off valve that is controlled by a vacuum line. Hmmmmm....a lot like a contactor switch!
Did I say "Switch"? Yes! A contactor is a switch. And today's contactors are way more robust of a switch than any mechanical switch available.
Tesla uses 2 contactors to disconnect the battery packs on their mass produced cars. No mechanical switch.

Thanks for the hijacking of my build thread! And thanks for starting this thread here, where it belongs!! "

6 Hours Ago

Stevo clicked Likes for this post: Should you have a mechanical, manual pack disconnect? by Ted Dillard

8 Hours Ago

Functional Artist replied to the thread Should you have a mechanical, manual pack disconnect?.
" Yup!

I even go "dual purpose" & use resettable circuit breakers for the fuse & main cut-off switch for all of the go karts that I design/make.

I also use a circuit breaker as a fuse & main cut-off switch, mounted right on the battery pack, on my bike.

But, mine is a low powered (48V) art bike. (I was originally offended by "low powered art bike" but, it's kinda true & I seem like it now) "

9 Hours Ago

frodus replied to the thread Should you have a mechanical, manual pack disconnect?.
" I say Sure. Brammo had a battery plug that could be disconnected while working on the bike.

For my Kart, I'm using SB350's for the disconnect between pack and the contactor. PLEASE, PLEASE fuse before this if you possibly can.

I won't be using a manual switch or e-stop that passes current. I'll have a BRB (Big red button) that interrupts the KSI on the controller I use, to disengage the contactor and stop the controller from electrically commutating. "

10 Hours Ago

Ted Dillard clicked Likes for this post: KwSAKI Mk1 (Ex 500) by aggrc

10 Hours Ago

Ted Dillard replied to the thread Your "OTHER" projects.
" OK, this is kind of off-the-wall for ElMoto, but I'm super exited about it. It's an idea I had about 10 years ago:

Attachment 8055

Many artists use photographs for source material. Many years ago, we worked on an idea to use a computer monitor to display photos for the artist, eliminating the inevitable transposition of a paper print. Finally, the technology has reached a point where it’s feasible and workable.

We used a Samsung Q6F television, and simply prepped the image with our layout and positioning in Photoshop. We loaded the image using a USB drive. Though color profiling the display, and driving it through a computer would result in a higher fidelity image, the on-screen adjustments seem to work fine, and allow the artist to adjust the display to taste.

The image appears entirely life-like, giving the artist the ability to paint as if the subject was sitting in the room. "

10 Hours Ago

aggrc replied to the thread KwSAKI Mk1 (Ex 500).
" UPDATE 2: I got the motor turning last night! Super close to a test ride. "

10 Hours Ago

Ted Dillard replied to the thread VOR.WORX.EMC.v3.0.
"
Quote Originally Posted by Stevo View Post
Any number of things? Any specific examples?

Sent from my Pixel 2 using Tapatalk
Sorry, I completely missed this.

Mostly things right off the pack. The thing that comes to mind first is wear/rubbing on the cable before the fuse. It depends on where you locate your pack, and how the leads are configured, of course. Dropping your bike in a puddle, stream or whatever. Malfunctions/leaks of devices in the low-voltage circuit. Dumping the bike - being able to shut off power if the throttle is stuck on (happened to me more times on gas bikes than I care to remember). I've even had my pack overheating for no apparent reason, and simply reached down and cut power so I could coast to a stop and figure out WTF was going on. I had a friend jokingly grab and twist my throttle while I was sitting on the bike, with it turned on. It was fairly exciting. I destroyed a pack by leaving the switch on, due to the Alltrax sapping the power - I actually put a "Power On" LED on the bars to make sure I'd never do that again. Kidproofing the bike - I've done several shows where kids are all over the thing, and did my best to keep them from killing themselves, but had the pack disconnected via the switch as well.

I could keep going. Unexpected things tend to happen the longer you build and ride these things.

Your call, of course, but you asked for reasons for the switch, and I'm givin' em to you. "

12 Hours Ago

Ted Dillard replied to the thread Should you have a mechanical, manual pack disconnect?.
" Pro:

- Easy, fast disconnect for working on the bike. (Depending on where your battery terminals are, it's not often too convenient to disconnect the pack using them. Also, if your terminals are sealed or whatever, disconnect there gives you wear and tear.

- Redundant safety. Sure, your contactor is supposed to take care of this for you, as well as fuses, and even two contactors, but then again, I'm supposed to be rich and good lookin'.

- Cheap, takes up no space, is really easy to wire in. $40. Game over.


Con:

I'm not seeing one. "

12 Hours Ago

Functional Artist replied to the thread VOR.WORX.EMC.v3.0.
" I am not trying to give you a hart time, but IMO Your "playin' with fire".

If (1) police officer, fireman, paramedic or even an average citizen gets hurt "fried"' while trying to help in a crash, it'll negatively affect the entire EV industry, community & movement.

I have heard of situations where first responders were reluctant (scared) to help someone in a wrecked vehicle because they saw it was an "electric conversion".

If it got around that there are "rogue" unswitchable DIY electric conversions around...

But, mainly it's for "your safety", your house has a "main" cut-off switch & industrial machines have "main" cut-off switches to allow (no to dictate) that the system is completely off (dead) & therefor safe(er) to touch/work on. "

12 Hours Ago

Ted Dillard created the thread Should you have a mechanical, manual pack disconnect?.
" Yes.

"

12 Hours Ago

Ted Dillard clicked Likes for this post: VOR.WORX.EMC.v3.0 by Stevo

12 Hours Ago