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  1. patrick_mahoney

    Ping 48V 15Ah LiFePo battery after a year

    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...
  2. patrick_mahoney

    How Fast is your Ebike versus How Fast do you want it?

    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.
  3. patrick_mahoney

    Hymotion/a123Systems new Prius L5 pack available...

    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...
  4. patrick_mahoney

    Astroflight charger for D/C lithium

    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...
  5. patrick_mahoney

    Article from an engineering magazine about future batteries

    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
  6. patrick_mahoney

    News.com: China e-bikes drive lead metal demand

    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
  7. patrick_mahoney

    3.7V 50Ah Lithium Polymer cell at all-battery.com

    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.
  8. patrick_mahoney

    3.7V 50Ah Lithium Polymer cell at all-battery.com

    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...
  9. patrick_mahoney

    Headlights...

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

    My 406 Hubmotor is spinning backwards...

    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...
  11. patrick_mahoney

    Safety of Different Lithium Battery Types

    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...
  12. patrick_mahoney

    Energy density of gasoline vs. Lipo batteries

    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...
  13. patrick_mahoney

    Headlights...

    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...
  14. patrick_mahoney

    Ocean Cheer 36v15ah LiFe pack - DIscharge Graph

    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...
  15. patrick_mahoney

    Headlights...

    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...
  16. patrick_mahoney

    Headlights...

    I'm bit confused. I'm new to the world of optics and LED's but I've spent hours reading over the last two days. From what I've read , there's a wide range of spectral responses for white LED's. I thought this page was really good for listing many of the leading commercially shipping white...
  17. patrick_mahoney

    Headlights...

    Ok, I took the plunge. I bought a Cree Q5 from DealExtreme along with a reflector (which hopefully will fit) and a glass cover. I'll probably need more than just one Q5, but I'll see how this one goes. Thanks for the links, cad. It's not like I'm unhappy with my halogen setup, but...
  18. patrick_mahoney

    Headlights...

    Thanks. Those are very impressive numbers. Still a bit out of my price range... but not by much. LED's have certainly made a lot of progress very quickly. Thanks again for the link.
  19. patrick_mahoney

    Headlights...

    I hunted a bit and I wasn't able to find a white 80Lm/W LED in a ~5W size that I could buy. Do you have any links of where to buy a ~5W ~400lumen white LED? The best that I could find was that Cree lamp that you linked to above at ~62Lm/W (@3.7W). Thanks
  20. patrick_mahoney

    Hyperion LBA10 question

    Sorry for the delay. Your diagram looks right, Dr.Bass. The datasheet from Aircraft-world.com ( http://www.aircraft-world.com/shopexd.asp?id=4913 ) is attached below. There's also a screenshot from the manual as well showing the hookup and it looks just like yours. Make sure you flip the...
  21. patrick_mahoney

    LiFe 18650 cells !!!

    Xyster beat me to it - while I was typing up pretty much the same thing.. he posted it. Still, this is interesting stuff. I'd like to see datasheets, Ypedal, when you get them. And I'd like to hear more about them as you learn more. Call me paranoid, but those look like burn marks on the...
  22. patrick_mahoney

    Lithium polymer battery shut-off in rocket

    :) I'm disappointed he named his company Armadillo Aerospace - rather than United Aerospace Corp. (UAC)
  23. patrick_mahoney

    Lithium polymer battery shut-off in rocket

    I was reading on Slashdot.org about John Carmack's Armadillo Aerospace's rocket crash. Reposted over at Slashdot: http://hardware.slashdot.org/comments.pl?sid=276831&threshold=-1&commentsort=3&mode=thread&cid=20322177 In a post to the forum, John Carmack mentioned: It wasn't the cause of the...
  24. patrick_mahoney

    Rant: Stop bothering with "energy/distance at a given s

    While I agree with CGame and everyone else who agreed, I don't think that it matters. I think people should collect data in whichever format they want. If they, for example, want to do Temperature-hours/per hour then I personally don't mind that time is a factor on the nominator and the...
  25. patrick_mahoney

    Lithium vs anything else, from a laymans point of view

    The Peukert effect (the capacity of a battery is reduced by higher current draw) is extremely pronounced on Alkaline batteries. A standard AA size alkaline battery (like AA from Energizer, or Duracell) has a capacity of approximately 2850 mAh when discharged at a rate of 5mA. But when run at...
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