Recent content by patrick_mahoney

First off, I have no affiliation with anyone in the E-bike business.. I'm just a guy who likes electric motors and bicycles. I bought a 48V 15Ah Lithium Iron Phosphate battery from Ping via his website last year in May 2009. Since then I've ridden something around 120 commuting trips along my...

Mine tops out at ~50kph (47-52kph depending on how much I'm pedalling and how topped out the batteries are). To be honest, this feels just about right to me. Most of the time I go a bit slower than this - usually around 35kphh - but it's nice to have speed when I need it.

According to the graph on this page, http://www.a123systems.com/hymotion/technology/performance_data It looks like the Prius goes to 35mph on battery power alone and then requires the engine to go faster - at least that's how I interpret the stair-step on the blue fuel line when the engine...

I've used my Astroflight 109 in discharge mode to discharge my 12s8p lithium ion pack by reconfiguring it as a 6s16p pack and then discharging it down to 3V/cell. I've only done it twice, but both times it worked fine - it took a really long time, but it worked fine. And it was a good way to...

There's an article in the Nov. 2007 issue of the IEEE Spectrum (IEEE => Institute of Electrical and Electronic Engineers) about the future of batteries and sees a growing synergy between batteries and ultracapacitors in the future. http://www.spectrum.ieee.org/nov07/5636 and later

Chinese e-bikes are increasing prices for lead: http://www.news.com/China-e-bikes-silently-drive-lead-demand/2100-11392_3-6212734.html?tag=nefd.top

You know, I did look through the recent posts here. But I didn't see it. I should have searched on the keyword "scary". ;) I thought it was new, I didn't realize it had come out a while ago.

http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=1967 Approx 1.4Kg Length：225mm Max Width：212mm Max Thickness：13.5mm Max And now, of course, the bad news: Cycle Life : ≥ 300 Times (80% of capacity discharged/charged) Max. Discharge Current: 1.0C (50A) Price: $239 And it's...

Dealextreme never did ship my Cree Q5 that I ordered - they mailed all the other parts to make the headlight, but not the Cree. :(

If you have the option to be able to change the motor wires, then swap any two of the three wires going to the motor. So if it's yellow=yellow, green=green, red=red, then make it yellow=red, green=green, red=yellow. But this only works if you can change the wires around.. on some they are all...

That chart also matches with my experience. Lithium cobalt batteries are relatively cheap (there's a nice all-battery.com 20% off coupon right now), they have much higher energy/weight compared to other chemistries (my 44V 18Ah pack weighs about 10lbs with it's case), but you want to be very...

Definitely the whole problem with electric vehicles is the difference in energy density between batteries and gasoline. If this weren't the case... we'd all be driving around in electrics. They are quieter, cleaner, require less maintenance and generally are more reliable... clearly the...

Thanks for the explanation, BobMcCree. It was very informative. You lost me a bit in the middle, I will admit, when you were talking about slits and measurement accuracy... but I mostly followed what you wrote. Very interesting reading. It still seems to me that LED's are well on their way...

To get 220V... You could rewire a circuit in your house... Most in the houses in the US actually get 220V (110V in two phases, 180 out of phase) in from the street and then the breaker boxes split this into two 110V sets. If you want 220V, you can just tap off of both inbound 110V instead...

Right. I agree that's how they work. But there's a clear emission - at least on the spectral intensity graphs - in the 460nm (blue) range. So it's like not all the light is being absorbed/converted by the phosphor and some is passing through. So on nearly all of the lights, they are emitting...