Search found 583 matches

by pdf
Oct 30 2013 12:52pm
Forum: Battery Technology
Topic: GE Battery 48V 20AH $370 - is it any good?
Replies: 9
Views: 1440

Re: GE Battery 48V 20AH $370 - is it any good?

Thanks, everyone, for the cautionary advice. Any suggestions for a better vendor for a 48v 10-15 AH battery that I can use with the bafang 750W mid-mount conversion kit? I'm looking for a battery that comes in a box for easy mounting on a rack of some kind rather than a raw, shrink-wrapped or duct-...
by pdf
Oct 30 2013 12:17pm
Forum: Battery Technology
Topic: 20 AH LiMnO2 "overheating" drawing 20 amps??
Replies: 58
Views: 4390

Re: 20 AH LiMnO2 "overheating" drawing 20 amps??

When you say the battery is in a plastic case, do you mean a case in addition to the plastic shrink that the cells are in? I originally assumed when you mentioned it was in a plastic case, you were talking about the shrink, but I think you are talking about another (maybe a hard) case to physically ...
by pdf
Oct 29 2013 2:29pm
Forum: E-Bike General Discussion
Topic: Do i trust this website?
Replies: 30
Views: 2824

Re: Do i trust this website?

Because i don't have a lot of experience, it's difficult to trust cheape sit's Would you trust them? Or do you know better sits? it's not that i am looking for something very special. Im looking for acommuter to drive to work (35Km) Speed 45KM/h. flat roads So my idee whas 1000W 15Ah LIFEPO4 bat. b...
by pdf
Oct 29 2013 1:35pm
Forum: E-Bike General Discussion
Topic: Do i trust this website?
Replies: 30
Views: 2824

Re: Do i trust this website?

The integration of the battery bag into the frame looks great. Other sellers could take note. I agree with the posting that all the parts of hi power cycles bikes (the other one in the US) likely come from China, regardless of where they are assembled. They are over-selling the battery and motor wit...
by pdf
Oct 29 2013 11:30am
Forum: Battery Technology
Topic: 20 AH LiMnO2 "overheating" drawing 20 amps??
Replies: 58
Views: 4390

Re: 20 AH LiMnO2 "overheating" drawing 20 amps??

Well, my two cents: I think if you want to run at that power level with that battery at that voltage, you need a bigger (more Ahr) battery. 24v is going to need a lot of current for a given power level. A 24V, 20 Ahr battery is the size of a 10 Ahr 48v battery, which is what I have and the same chem...
by pdf
Oct 28 2013 9:43am
Forum: Battery Technology
Topic: 20 AH LiMnO2 "overheating" drawing 20 amps??
Replies: 58
Views: 4390

Re: 20 AH LiMnO2 "overheating" drawing 20 amps??

Entirely possible you have multiple problems. Hot bms getting hotter when the cells themselves get pretty warm pulling hard up that hill. But it's no solution to say, "just ride in the winter". I find it hard to believe your pack loves a 5c discharge. Doing it in tests is one thing, loving doing it...
by pdf
Oct 28 2013 9:36am
Forum: E-Bike Technical
Topic: I Think I Screwed Up My Battery - Please Help
Replies: 8
Views: 788

Re: I Think I Screwed Up My Battery - Please Help

If they are actually zero, they are toast. Know from personal experience. It is possible you can force a charge, but the capacity will be GREATLY diminished and the chance of a battery failure, possibly resulting in a battery fire, is very real. Chuck them out.
by pdf
Oct 28 2013 9:32am
Forum: E-Vehicles General Discussion
Topic: Hemp powered, Hemp made
Replies: 38
Views: 5226

Re: Hemp powered, Hemp made

Living in Iowa forces commercial growing in your face and even non-farmers pick up on a few facts. There's only so much cultivation any given plot of land can sustain, unassisted. Farming has gone from relying on biological processes in the soil to now using soil as a substrate for fertilizer, simi...
by pdf
Oct 24 2013 11:28am
Forum: Battery Technology
Topic: Ba neh neh neh......My Charger Blew up :(
Replies: 20
Views: 2309

Re: Ba neh neh neh......My Charger Blew up :(

it should not cause it to blow up, but it is harder on them. since you discussed the history, you are likely looking at damage caused by carrying the charger on the bike or if you dropped it. they have electronic components inside that are attached to a thin pcb and when the pcb vibrates or is flex...
by pdf
Oct 23 2013 7:13pm
Forum: E-Bike General Discussion
Topic: Compressed air propulsion
Replies: 14
Views: 1160

Re: Compressed air propulsion

I did some searching on paintball tanks, looks like 90in^3 (1.47L) is the largest volume I could find. At 4,500psi, that tank is packing ~228kJ of energy, or 228,000watt-seconds of energy. In watt hours, that's just 63Wh. Roughly the same energy in a standard 6-cell laptop battery, or a bit less en...
by pdf
Oct 23 2013 12:45pm
Forum: Battery Technology
Topic: Ways to re-charge a lipo battery after it drops below 2.7v
Replies: 64
Views: 5534

Re: Ways to re-charge a lipo battery after it drops below 2.

See, what confuses me here is that you guys are giving contradictory info. Over. and over. and over. ...rest deleted for space +1. The guy has a point. Practically speaking though, in terms of a low voltage cutoff, the difference between, say 3.6 and 2.7 is about 10 feet of road. At some point your...
by pdf
Oct 23 2013 11:48am
Forum: Battery Technology
Topic: Ways to re-charge a lipo battery after it drops below 2.7v
Replies: 64
Views: 5534

Re: Ways to re-charge a lipo battery after it drops below 2.

You need to look at this graph again: http://neptronix.org/forumpics/lipotutorial/24_dischargingmechanics.gif Lipo is different from other battery chemistries you might be familiar with. The discharge curve has a VERY pronounced drop off at a relatively high value. Only around the middle of the disc...
by pdf
Oct 21 2013 9:14am
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1611
Views: 187118

Li ion battery article

The October issue of Chemical Engineering Progress has a nice multi-article section on many secondary lithium (lithium ion) chemistry batteries. It is a good overview of current and possible future battery technologies. It discusses some of the theoretical limits to battery technology as well and ad...
by pdf
Oct 17 2013 8:10pm
Forum: Battery Technology
Topic: 48 v 35.2ah li-ion battery pack
Replies: 104
Views: 8569

Re: 48 v 35.2ah li-ion battery pack

You can do it two ways, but you don't mention what capacity you are shooting for. Let's assume for the sake of illustration, that you are building a 16 Ahr 16s pack from 8 Ahr cells. You can either: 1) Make two sets of 16 cells in series and then put the two units of 16s in parallel with each other,...
by pdf
Oct 17 2013 12:18pm
Forum: Battery Technology
Topic: 48 v 35.2ah li-ion battery pack
Replies: 104
Views: 8569

Re: 48 v 35.2ah li-ion battery pack

To get to 48v (nominal), this is usually a 15 or 16 cells-in-series (shorthand is 15s or 16s) pack with LiFePO4. Let's assume 16. That will be like 58V right off the charger. Then, to get to your desired capacity, you will just multiply the single cell capacity (since they are in series, the capacit...
by pdf
Oct 17 2013 9:11am
Forum: E-Bike General Discussion
Topic: Flykly, Roola, Electron, Zehus, Copenhagen all in 1 ewheels
Replies: 55
Views: 17634

Re: Flykly Smart wheel on kickstarter

20Wh/mile isn't unreasonable at 36v speeds, 10 with assist (which is it's only mode) is possible. 20mph @250 watts sounds right, 325wh should do more than an hour of riding. I'd say 25 mile range is probably reasonable. I disagree. I have a 15 Ahr 48V battery that weighs 18 lbs. Assuming half the w...
by pdf
Oct 15 2013 11:18am
Forum: E-Bike Technical
Topic: Motor starts and stops
Replies: 16
Views: 1622

Re: Motor starts and stops

I have never seen one of the analyzers you have used so I can't comment intelligently on the signals you are getting. However, I looked up a youtube video someone posted of its use with a hub motor. Only two of the LEDs for the Halls are lighting so something is different there. Do you get a signal ...
by pdf
Oct 14 2013 2:51pm
Forum: Battery Technology
Topic: 48 v 35.2ah li-ion battery pack
Replies: 104
Views: 8569

Re: 48 v 35.2ah li-ion battery pack

Each of your groups has 3.7V and 8.8Ah. You have 16 groups like this. If you put these in series, you will have roughly 60V nominal with 8.8Ah capacity. If you want 35.2Ah, that means you have to configure 4 groups (16 cells) in parallel, which leaves you with only 4 such clusters in series = 15V p...
by pdf
Oct 14 2013 1:32pm
Forum: E-Bike Technical
Topic: Motor starts and stops
Replies: 16
Views: 1622

Re: Motor starts and stops

Since the motor was previously running and everything was normal, I don't see how the Halls or phase wires could be out of order. Given that the motor got very hot for some reason, it is a good idea to check the Halls at this point. If the motor is put together, you can rotate it slowly so that the ...
by pdf
Oct 11 2013 4:22pm
Forum: E-Bike Technical
Topic: Motor starts and stops
Replies: 16
Views: 1622

Re: Motor starts and stops

That motor did not look like I thought it would and then I read your signature and see that it is a mid-drive Eco-Speed. Cool! I am not familiar with that motor but I have heard they use a BMS motor. Can you take a photograph of the other side of the motor? I actually do not know if it is an in-runn...
by pdf
Oct 10 2013 8:04pm
Forum: E-Bike Technical
Topic: Motor starts and stops
Replies: 16
Views: 1622

Re: Motor starts and stops

Shrink should work, but the little plastic tubes are very resistant to abrasion. But shrink should work. The Halls should give a signal when a magnet passes by them. If one is not giving a changing signal at the harness when the motor is turned, it is probably bad, or the wiring may be bad. Mine tes...
by pdf
Oct 09 2013 10:16am
Forum: E-Bike Technical
Topic: Motor starts and stops
Replies: 16
Views: 1622

Re: Motor starts and stops

is it repairable, how can i know for sure? where can i get new halls? will this do? http://www.ebike.ca/store/photos/HallSensor.jpg i've run the motor for weeks, and the combo i used does not use over to 2 amps in no load, so it can't be that. right? I just did a Halls replacement. Don't know if th...
by pdf
Oct 06 2013 6:39pm
Forum: E-Bike Build Threads / Photos & Video
Topic: Monzilla - BURNED IN LIPO FIRE AUGUST 11
Replies: 136
Views: 18283

Re: Monzilla - BURNED IN LIPO FIRE AUGUST 11

There is nothing that can make your family totally safe. I have a gas water heater in the basement. Last year, a home in my town was blown to bits by a gas leak. No survivors. I have two cars in my garage, tanks full of gasoline. I have a set of shelves with propane, ethanol, toluene, you name it. I...
by pdf
Oct 06 2013 5:54pm
Forum: E-Bike General Discussion
Topic: Ebike down.
Replies: 19
Views: 1366

Re: Ebike down.

You mention you bought the kit a while ago. Have you used the kit before when it worked or is this the first time you have tried it?
by pdf
Oct 06 2013 5:48pm
Forum: E-Bike Technical
Topic: Did I get ripped off?
Replies: 30
Views: 2126

Re: Did I get ripped off?

+1 for Rassy's advice. On the bright side, lead acid batteries are the least expensive kind so even if they are wrecked, it could be much worse! Do as Rassy suggests and welcome to the game! If the controller had the right low voltage cutoff for your battery, then it was cutting off to keep you from...