Search found 159 matches

by cerewa
Jun 27 2008 10:38am
Forum: E-Bike Non-hub Motor Drives
Topic: Using RC motors on E-bikes [Archive]
Replies: 1244
Views: 168125

Re: Using RC motors on E-bikes

If efficiency is so important to you, address wind resistance first, and don't just blindly accept upright design and wind resistance as something you can do nothing about. Idunno about the rest of you, but I (who can't afford a good aerodynamic recumbent) put some cheap aerobars on my upright bike...
by cerewa
Jun 23 2008 8:03pm
Forum: E-Vehicles General Discussion
Topic: Amazing Air Car from India
Replies: 31
Views: 3297

Re: Amazing Air Car from India

Fill it up at home with a compressor powered directly by the wind? :D
by cerewa
Jun 23 2008 7:59am
Forum: Battery Technology
Topic: bypassing battery heat sensor - YESA LiFePO4
Replies: 2
Views: 454

Re: bypassing battery heat sensor - YESA LiFePO4

What I can't figure out for sure is whether the heat sensor is supposed to show almost-zero resistance when the temperature is below the cutoff (which is 65 degrees C). The sensor makes a little bit of a rattling noise if shaken, and the bike was cutting out at temperatures above 90 degrees earlier,...
by cerewa
Jun 22 2008 10:50pm
Forum: Battery Technology
Topic: bypassing battery heat sensor - YESA LiFePO4
Replies: 2
Views: 454

bypassing battery heat sensor - YESA LiFePO4

my LiFePO4 battery's BMS came with a heat sensor, which broke. This is a YESA pack I bought on Ebay. Here's the deal. My multimeter shows that the wires for the heat sensor are at about 5.8V when they're disconnected. The BMS seems to be cutting power off with the heat sensor disconnected, whether t...
by cerewa
Jun 22 2008 8:43pm
Forum: Battery Technology
Topic: Ping and yesa battery packs
Replies: 13
Views: 1289

Re: Ping and yesa battery packs

I don't think the YESA pack is two times as good. It is packaged better, though - plastic shrink-wrap is a pretty nice packaging method for these batteries. My YESA pack's BMS seems to have run in to a broken heat sensor problem though. EDIT - I WAS WRONG - the BMS is fine, the problem is with my mo...
by cerewa
Jun 22 2008 8:46am
Forum: Battery Technology
Topic: Saft 100C cont. lithium batts
Replies: 22
Views: 1419

Re: Saft 100C cont. lithium batts

I couldn't imagine shorting even one out; 1,600A pulse, and that's only what it's RATED for. What will the internal resistance allow? O.o I think the internal resistance will allow energy-discharge to occur at about the same rate as in dynamite. To the casual observer, the energy discharge will pro...
by cerewa
Jun 22 2008 8:45am
Forum: Battery Technology
Topic: Yesa Battery ,Is it possible to connect them in series?
Replies: 4
Views: 490

Re: Yesa Battery ,Is it possible to connect them in series?

They charge from 0% to full in less than 8 hours. When I received mine I think it was at 80% or 90% of full charge. I read on the YESA website that it's OK to connect their batteries in series but it's not recommended to connect them in parallel. To connect in series, you will want to understand wha...
by cerewa
Jun 20 2008 9:40pm
Forum: Battery Technology
Topic: 23,000 watt hour battery
Replies: 3
Views: 536

Re: 23,000 watt hour battery

It's a 23,000 watt hour rated lead-acid battery that has been "out of service" for 4 years. As a 48V setup it reads 50.5V on the person's meter. My understanding is that 12V-rated SLA batteries are at 13V when charged so that person's pack is substantially below that (or being measured inaccurately)...
by cerewa
Jun 14 2008 9:51pm
Forum: E-Bike Technical
Topic: I confirm... IRFB4110 Mosfet CAN BLOW !!!
Replies: 70
Views: 10321

Re: I confirm... IRFB4110 Mosfet CAN BLOW !!!

guys.. how could you have though that i could be able to blow a X5 !!!! :P it still impossible.. not me.. not anyone did that.. like i know...
I bet you could blow an X5 if you had a 50KW controller for it. :p
by cerewa
Jun 14 2008 9:41pm
Forum: E-Bike Technical
Topic: e-bike throttles
Replies: 2
Views: 562

e-bike throttles

It looks like my cyclone e-bike was put out of commission by a little bitty short circuit that was my own fault because I pushed the wires around a little when I plugged the hole to waterproof it. It's ready to go, except that in the mean time the throttle got broken while the bike was sitting under...
by cerewa
Jun 14 2008 6:29pm
Forum: E-Bike Technical
Topic: Aerodynamics thread?
Replies: 131
Views: 16824

Re: Aerodynamics thread?

And how do you weave through traffic when you are so low and can't see over the cars?
If you have to ask, you probably don't want a recumbent bike.

Low bikes are not so good for filtering-forward in traffic.
by cerewa
Jun 14 2008 7:44am
Forum: E-Bike General Discussion
Topic: power to weight ratio hub motor comparisons, any out there?
Replies: 8
Views: 856

Re: power to weight ratio hub motor comparisons, any out there?

I'm pretty sure power-to-weight ratio tends to be better on the geared hubmotors, but the big heavy gearless hubmotors can take a lot more power before overheating.
by cerewa
Jun 11 2008 12:59am
Forum: E-Bike Technical
Topic: "Wagon" steering on tadpole... bad idea?
Replies: 24
Views: 1247

Re: "Wagon" steering on tadpole... bad idea?

You guys are right, that "wagon" steering eliminates the need for Ackermann steering correction. Instead, the wheels will handle as well as the rear wheels of a car do - no need for them to point in a non-parallel direction for turning. http://en.wikipedia.org/wiki/Ackermann_steering_geometry has a ...
by cerewa
Jun 09 2008 8:17pm
Forum: E-Bike General Discussion
Topic: neat trick to visualize your e-bike maximum distance
Replies: 7
Views: 1020

Re: neat trick to visualize your e-bike maximum distance

For the "visualize your max e-bike distance", what's the easiest way to find your own latitude&longitude? or do you not even need that?
by cerewa
Jun 09 2008 8:15pm
Forum: E-Bike General Discussion
Topic: What is your dream ebike?
Replies: 25
Views: 5235

Re: What is your dream ebike?

My dream e-bike is gonna be a fully enclosed, very light and aerodynamic (some BMW engineer biker guy said he had made a motor-less one from carbon&kevlar that was just 30 pounds) 2wheel recumbent bike. Good closeable air vents. :) An efficient, very low maintenance motor and range of at least 40 mi...
by cerewa
Jun 05 2008 10:49pm
Forum: E-Bike General Discussion
Topic: hubmotor efficiency
Replies: 10
Views: 825

hubmotor efficiency

Let's say you had two different non-geared hubmotors, one with more windings and one with fewer, like crystalyte 404 and 4011. You're attaching each hub to a 26" rim, and you want them to go the same speed - you find batteries with the right voltage to make both of them go about 18mph* on flat groun...
by cerewa
Jun 05 2008 10:35pm
Forum: E-Bike General Discussion
Topic: Arguement thread!!!
Replies: 58
Views: 4461

Re: Arguement thread!!!

If it has pedals it is street legal at any speed. I just looked it up! Ha! Take that you reprobate bastards! I taped pedals to the windshield of my car. I have decided to cancel the insurance and remove the license plate, because it is a "bicycle" now - it has pedals. And the electric motor is capa...
by cerewa
Jun 05 2008 7:03pm
Forum: E-Bike Technical
Topic: off subject question on watts
Replies: 11
Views: 820

Re: off subject question on watts

Thats Dirt cheap! (5 cents/kwh) My town runs its own power station, and we still pay 11 cents, and consider ourselves lucky! otherDoc At a rate of 5 to 7 cents per KWH, the electric company is probably losing more money, the more people use electricity. There's probably some government regulation k...
by cerewa
Jun 05 2008 6:51pm
Forum: E-Bike Non-hub Motor Drives
Topic: Using RC motors on E-bikes [Archive]
Replies: 1244
Views: 168125

Re: Using RC motors on E-bikes

Some of those big RC brushless motors have enough torque to work really well at moderate power (750W and down) with only one stage 1:8 gear reduction to a 20" or 26" bike wheel. The only thing stopping me from doing that is that I don't know how to put a suitable sprocket on an RC motor or on my bik...
by cerewa
Jun 05 2008 6:43pm
Forum: E-Bike General Discussion
Topic: Arguement thread!!!
Replies: 58
Views: 4461

Re: Arguement thread!!!

I've already tried raw oatmeal. It doesn't work for me.

Cooked oatmeal is great though, for real.
by cerewa
Jun 05 2008 6:42pm
Forum: E-Bike General Discussion
Topic: GPS Global Positioning System with maps of bike trails
Replies: 4
Views: 690

Re: GPS Global Positioning System with maps of bike trails

If you run a DC-DC converter for 12V, and you don't already have lights running off your main battery...

12V DC supply is a great possibility for headlights and taillights.
by cerewa
Jun 05 2008 6:24pm
Forum: E-Bike General Discussion
Topic: Arguement thread!!!
Replies: 58
Views: 4461

Re: Arguement thread!!!

How about oatmeal? I eat a bowl of raw oatmeal (uncooked) every day. Quick Quaker oats with cold milk and some honey (with banana of course). Gives tons of energy for about 3 to 4 hours before you need to "Recharge". Way better than slimey cooked oatmeal. Keeps my human engine running at its prime....
by cerewa
Jun 04 2008 7:47am
Forum: General Discussion
Topic: gas price thread
Replies: 774
Views: 71035

Re: gas price thread

This man is my hero BTW: "Muhammad Yunus of the Grameen Bank". +1, folks should read about all the stuff he suggests in terms of non-profit businesses that charge enough for services to cover their own costs (and no more) and about all the things you can do with a self-sustaining non profit organiz...
by cerewa
Jun 04 2008 7:06am
Forum: E-Vehicles General Discussion
Topic: 11,000 watt-hours equal about a gallon of gasoline
Replies: 45
Views: 5316

Re: 11,000 watt-hours equal about a gallon of gasoline

The real solution, for a BEV, is to employ batteries that can be charged at at least 10C (6 minutes from 0% to 100%) and use powering stations that can supply the massive power needed to recharge the battery pack in so short a time, probably using its own batteries to store that power until needed,...
by cerewa
Jun 01 2008 7:20pm
Forum: E-Bike General Discussion
Topic: what motor/system to buy?
Replies: 7
Views: 1011

Re: what motor/system to buy?

The reason I say the motor needs to be powerful is that the person who wants the bike is heavy and can't pedal a whole lot. I'm sure 500W would be fine, actually, if low speed uphill efficiency is ok. The hills I'm talking about are Philadelphia suburbs hills. These hills are not as steep as the wor...