Recent content by busted_bike

OK Go - This Too Shall Pass http://www.youtube.com/watch?v=qybUFnY7Y8w

And yet a vehicle powered only by the ground goes nowhere... :wink: Perhaps you're oversimplifying?

Unfortunately, I neglected to look at the date when I read this post - I didn't realize I was complicit in thread necromancy. Nevertheless, I missed it the first time around and it is something interesting to ponder. But I agree with John - pitch-adjustable blades on the prop may be helpful...

I haven't read the whole thread, but I think I get it - maybe - so I'll try my own twist on an explanation. Forgive me if someone has already taken the same tact on an explanation. First, it seems obvious that a tailwind turning a prop geared to the wheels would make the thing move forward, at...

LFP is pretty much spot on - I uploaded a simulation image that I created previously to explain why it's necessary to use the rebound voltage delta for calculating Ri, rather than droop. If you use droop rather than rebound, there is some voltage sag due to normal discharge effects that muddles...

How many Coulombs is your battery? ;)

Just a suggestion - I suspect a lot of the material for an ES wiki has already been written, here and in other places. Basic electronics units, math, and theory is all over the web. Some of it is even well written. If someone can find this site, they can probably find another with...

Pick up some nice aftermarket whale penis leather seats and park wherever the hell you want to. The collateral damage (gaping holes in local parking garages, crushed cars in your wake) can be classified as externalities. :wink:

I get it - externalities aren't your problem. I also suspect you've read one too many "Freakonomics" books. :wink: Also, since your reasoning seems to be something along the lines of "I have plenty of money, cost isn't a factor", I'm curious as to why you didn't chose to go with a Peterbilt.

I understand that you have an idea in mind that you're running with, but I'm going to reiterate what others in this thread have already stated: regen on a bike is useless in practice. Here's a link that does a reasonable job of explaining why. http://www.ecospeed.com/regenbraking.pdf Now - if...

How does it deal with the fact that my laptop wants 19.5V, my router wants 12V, and my cell phone wants 5V? Goodness knows what else I have laying around that wants 18V / 24V / 48V...

Good question. As I recall, it was a fresh cell that would have had only a 33% charge on it. I certainly wouldn't rule out the possibility that your cells behave differently. When you get down to the details, different chemistry cells do seem to behave quite differently. As for the...

As I recall, about 2/3 of the energy released for virtually any lithium chemistry cell on ignition is due to combustion of the electrolyte. So even a completely drained LiFeP04 cell represents a potential fire hazard under the right circumstances. So I'm with Jeremy on this one.

I've measured the tempco of a LiFeP04 cell at 50uV/degC (single cell, from 23C-40C). I don't know what your pack consists of, so lets assume a hypothetical 22 cell series connection and a 20C temperature rise. 50uV/degC * 22 cells * 20C = 22mV Your pack Voltage rose by an order of magnitude...

Now that's a rule of thumb!