Search found 194 matches

by patrick_mahoney
Oct 07 2010 12:32pm
Forum: Battery Technology
Topic: Ping 48V 15Ah LiFePo battery after a year
Replies: 2
Views: 786

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 6 mile...
by patrick_mahoney
Sep 08 2008 12:24am
Forum: E-Vehicles General Discussion
Topic: How Fast is your Ebike versus How Fast do you want it?
Replies: 42
Views: 3732

Re: 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.
by patrick_mahoney
May 02 2008 11:17pm
Forum: Battery Technology
Topic: Hymotion/a123Systems new Prius L5 pack available...
Replies: 19
Views: 2554

Re: 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 goes abov...
by patrick_mahoney
Apr 17 2008 6:58pm
Forum: Battery Technology
Topic: Astroflight charger for D/C lithium
Replies: 5
Views: 848

Re: 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 find th...
by patrick_mahoney
Nov 05 2007 12:05am
Forum: Battery Technology
Topic: Article from an engineering magazine about future batteries
Replies: 6
Views: 1021

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 In 1995, a small fleet of in...
by patrick_mahoney
Oct 05 2007 9:42pm
Forum: Battery Technology
Topic: 3.7V 50Ah Lithium Polymer cell at all-battery.com
Replies: 2
Views: 1061

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.
by patrick_mahoney
Oct 05 2007 8:01pm
Forum: Battery Technology
Topic: 3.7V 50Ah Lithium Polymer cell at all-battery.com
Replies: 2
Views: 1061

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 the non-LiFe...
by patrick_mahoney
Oct 04 2007 11:55pm
Forum: E-Bike Technical
Topic: Headlights...
Replies: 105
Views: 14816

Dealextreme never did ship my Cree Q5 that I ordered - they mailed all the other parts to make the headlight, but not the Cree. :(
by patrick_mahoney
Sep 19 2007 9:41pm
Forum: E-Bike Technical
Topic: My 406 Hubmotor is spinning backwards...
Replies: 18
Views: 2529

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 in a p...
by patrick_mahoney
Sep 14 2007 10:54am
Forum: Battery Technology
Topic: Safety of Different Lithium Battery Types
Replies: 2
Views: 1744

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 careful...
by patrick_mahoney
Sep 10 2007 1:03am
Forum: Battery Technology
Topic: Energy density of gasoline vs. Lipo batteries
Replies: 17
Views: 2868

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 downside to ...
by patrick_mahoney
Sep 07 2007 9:07pm
Forum: E-Bike Technical
Topic: Headlights...
Replies: 105
Views: 14816

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 taking...
by patrick_mahoney
Sep 07 2007 4:18pm
Forum: Battery Technology
Topic: Ocean Cheer 36v15ah LiFe pack - DIscharge Graph
Replies: 19
Views: 4517

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 of a 110V ...
by patrick_mahoney
Sep 07 2007 2:51pm
Forum: E-Bike Technical
Topic: Headlights...
Replies: 105
Views: 14816

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 strongl...
by patrick_mahoney
Sep 07 2007 12:38pm
Forum: E-Bike Technical
Topic: Headlights...
Replies: 105
Views: 14816

all of the white leds use a blue led to excite a phosphor which peaks at close to 580 nm. they do this on purpose because they are meant to produce illumination for the human eye. 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 wh...
by patrick_mahoney
Sep 05 2007 6:47pm
Forum: E-Bike Technical
Topic: Headlights...
Replies: 105
Views: 14816

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 there's something ...
by patrick_mahoney
Sep 04 2007 8:58pm
Forum: E-Bike Technical
Topic: Headlights...
Replies: 105
Views: 14816

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.
by patrick_mahoney
Sep 04 2007 6:23pm
Forum: E-Bike Technical
Topic: Headlights...
Replies: 105
Views: 14816

Actually LEDs are regularly at 80Lm/W these days and it is pretty easy to put together an 80% efficinecy switcher. Dan 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 f...
by patrick_mahoney
Aug 30 2007 9:33pm
Forum: Battery Technology
Topic: Hyperion LBA10 question
Replies: 10
Views: 2398

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 master/slav...
by patrick_mahoney
Aug 23 2007 12:02pm
Forum: Battery Technology
Topic: LiFe 18650 cells !!!
Replies: 21
Views: 3267

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 solder join...
by patrick_mahoney
Aug 22 2007 10:42pm
Forum: Battery Technology
Topic: Lithium polymer battery shut-off in rocket
Replies: 5
Views: 893

:)

I'm disappointed he named his company Armadillo Aerospace - rather than United Aerospace Corp. (UAC)
by patrick_mahoney
Aug 22 2007 9:53pm
Forum: Battery Technology
Topic: Lithium polymer battery shut-off in rocket
Replies: 5
Views: 893

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: We started out with a normal 90 se...
by patrick_mahoney
Aug 19 2007 11:35am
Forum: E-Vehicles General Discussion
Topic: Rant: Stop bothering with "energy/distance at a given s
Replies: 9
Views: 1460

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 denominator,...
by patrick_mahoney
Aug 10 2007 2:57pm
Forum: Battery Technology
Topic: Lithium vs anything else, from a laymans point of view
Replies: 4
Views: 1421

Re: Lithium vs anything else, from a laymans point of view

So, a couple of weeks ago I put two AA lithium batteries in it. It's now gone five rounds and the battery gauge shows full! If they do the same thing in my bike they will be more than worth the money over SLA. We'll see. The Peukert effect (the capacity of a battery is reduced by higher current dra...