Search found 583 matches

by pdf
Sep 17 2013 1:50pm
Forum: Battery Technology
Topic: NMC vs LiPo charging
Replies: 39
Views: 4941

Re: NMC vs LiPo charging

You can always do a shitty job with any cell any chemistry. There are LiFePO4 cells that are junk after 50cycles, and there are LiFePO4 cells that are still at >100% original capacity at 500cycles. Cycling decay depends on many factors, the cathode material type and structure is only one of those f...
by pdf
Sep 17 2013 8:57am
Forum: E-Bike Build Threads / Photos & Video
Topic: Monster (build thread, Lots of pics, Bike Porn included)
Replies: 252
Views: 76302

Re: Monster (build thread, Lots of pics, Bike Porn included)

Just read this thread. Awesome bike. Great story all the way around. Very funny part about the dishwasher. Would be funny to have your first reaction to the smoke on film.

Anyway, really cool bike. Love the frame.
by pdf
Sep 13 2013 11:40am
Forum: E-Bike General Discussion
Topic: Anyone build up a Jekyll 3?
Replies: 11
Views: 756

Re: Anyone build up a Jekyll 3?

Nice bike. One other thing to think of is where you plan to put the batteries. The forward triangle on the bike in the picture (assuming this is the same as yours) is on the small side. You mention not wanting the batteries over the rear wheel, so you might want to look at some layouts and think abo...
by pdf
Sep 13 2013 10:35am
Forum: Battery Technology
Topic: RC smoke filter
Replies: 23
Views: 1769

Re: RC smoke filter

For now I charge outside in the barbecue, but I plan to charge in the fireplace w/smoke alarm relay triggered to start a fan poised high in the chimney to suck all the fumes straight out the chimney. I will test this periodically to make sure it works, and I will use 2 smoke alarms for redundancy. ...
by pdf
Sep 13 2013 9:25am
Forum: Battery Technology
Topic: RC smoke filter
Replies: 23
Views: 1769

Re: RC smoke filter

lipo bags anyone? http://www.hobbyking.com/hobbyking/store/RC_PRODUCT_SEARCH.asp?strSearch=lipo+bag they contain the fire from charging and failures. i think lithium and water is not good i think it is better to let it burn it's self out. \ I am not sure how effective the bags are on large packs. S...
by pdf
Sep 12 2013 2:46pm
Forum: Battery Technology
Topic: RC smoke filter
Replies: 23
Views: 1769

Re: RC smoke filter

Any filter that could make gases safe for inside the house would be ridiculously expensive. It would have to have a particulate filter (probably several in layers) and appropriate adsorbents for removing gases. Activated carbon is relatively cheap but will only remove some compounds and probably not...
by pdf
Sep 11 2013 8:20pm
Forum: E-Bike General Discussion
Topic: My favorite toy was stolen
Replies: 8
Views: 627

Re: My favorite toy was stolen

Bill Nye the science guy wrote:I have nightmares about this, maybe the b*stard will have a lipo fire and burn his crappy house down.
HA! Hopefully no one inside though. Hope you see your bike again. That sucks on many levels.
by pdf
Sep 11 2013 8:18pm
Forum: E-Bike General Discussion
Topic: Near fail experience, Dropouts
Replies: 8
Views: 553

Re: Near fail experience, Dropouts

Torque arms, for sure. You can't get the axle nuts tight enough. I have found that axles that fit tightly in the dropouts (that is, larger axles) tend to spin out less easily than smaller diameter axles, but when the dropouts are spread a little, you are sure to spin the axle if you don't add a torq...
by pdf
Sep 10 2013 9:51pm
Forum: Battery Technology
Topic: Yet another Lipo Fire
Replies: 43
Views: 2299

Re: Yet another Lipo Fire

I found a post listing the 5 likely causes of lipo fire, and an explanation of each on another forum: http://www.rctech.net/forum/electric-road/182219-understanding-lipo-fires-101-a.html A bms should sort out 3 of them. Hard case batteries a 4th. Leaving internal shorts out of our control. Nice met...
by pdf
Sep 10 2013 5:27pm
Forum: Battery Technology
Topic: Yet another Lipo Fire
Replies: 43
Views: 2299

Re: Yet another Lipo Fire

bulk charging puffed LiPO is hazardous If bulk charging is another way of saying over charging then I'm fully with you on that. The problem with puffed cells remains in any charging scenario though. Not just highly questionable one's. Puffed=Damaged. It also means there is movement within the cell....
by pdf
Sep 10 2013 8:36am
Forum: Battery Technology
Topic: Yet another Lipo Fire
Replies: 43
Views: 2299

Re: Yet another Lipo Fire

I'm sure what this thread needs is another opinion (NOT) but based on my very similar experience, bulk charging a puffed (i.e., probably internally failing) pack is a fire waiting to happen. I personally can't tell what caused that fire based on what is left. Could have been a short, could have been...
by pdf
Sep 05 2013 12:02pm
Forum: Battery Technology
Topic: Bestech power BMS review
Replies: 15
Views: 1346

Re: Bestech power BMS review

What are the two white wires at the top of the first diagram, with adhesive on them? Is this a sensor (temp?) of some sort?
by pdf
Sep 04 2013 7:03pm
Forum: E-Vehicles General Discussion
Topic: CNN story of e-cargo bike
Replies: 10
Views: 1365

Re: CNN story of e-cargo bike

I own an Xtracycle and while this is the first time I've seen a Boda Boda, I do like the shorter wheel base. The wheel base on the Xtracycle is both its strength and weakness. Great when riding, but a biatch to transport anywhere. If you can't ride it there, you are SOL. Not completely sold but it d...
by pdf
Sep 04 2013 10:06am
Forum: E-Vehicles General Discussion
Topic: CNN story of e-cargo bike
Replies: 10
Views: 1365

CNN story of e-cargo bike

From today's CNN.com http://whatsnext.blogs.cnn.com/2013/09/04/new-electric-bike-can-haul-100-pounds-of-cargo/?hpt=hp_c3 Guy who designed it, Neal Saiki, is said to be founder of Zero. I assume that is true, but not familiar with details of Zero. A couple of quotes: "The cargo bikes on the market ar...
by pdf
Sep 03 2013 10:12am
Forum: E-Bike General Discussion
Topic: Best methods to secure ebikes in public?
Replies: 60
Views: 2889

Re: Best methods to secure ebikes in public?

This is such a geography dependent question. Where I live, bike theft is so rare, if you lock your bike at all, you are probably OK. Plenty of bikes are locked by the FRONT tire and that is with quick-releases. In NYC, I don't think you can have enough lock. I use a u-bolt with a short throat so it ...
by pdf
Sep 03 2013 8:19am
Forum: E-Bike Build Threads / Photos & Video
Topic: Monzilla - BURNED IN LIPO FIRE AUGUST 11
Replies: 136
Views: 18954

Re: Monzilla - BURNED IN LIPO FIRE AUGUST 11

Posting since this thread has a fair bit of lipo fearing / endorsing traffic. I charge / discharge my HK lipos in a liposack - http://www.liposack.com/products.htm Products like this shouldn't make you complacent about keeping an eye on things, but seem to contain a mishap pretty well if you take a...
by pdf
Sep 02 2013 11:09pm
Forum: E-Bike Technical
Topic: "LiPO", another "be careful" warning...
Replies: 54
Views: 4100

Re: "LiPO", another "be careful" warning...

RoadWrinkle wrote:I am guessing LIPO chemistry has the best power :?: output to weight ratio and that is why they are so popular despite the fire risks? Is this true?
I'd say that is a fair statement, based on my experience. You get a lot of C rating for your money also. Just be careful.
by pdf
Sep 01 2013 1:28pm
Forum: Battery Technology
Topic: BMS for LiPo: yes or no? what is it?
Replies: 14
Views: 7863

Re: BMS for LiPo: yes or no? what is it?

The cells need to stay balanced no matter how you do it. Plenty of opinions about what balanced means. Also, if a cell goes under 2.7v, replace it. Printed on all the LiPo I've ever used, it says to charge with flammables at least 10 feet away. That is pretty good advice. For me, I'd use a BMS but I...
by pdf
Aug 30 2013 9:27am
Forum: E-Bike Technical
Topic: best parts to build a e bike with
Replies: 23
Views: 1458

Re: best parts to build a e bike with

999zip999 wrote:I would paint the bike with solar paint so it will always have a full charge.
You could, but pedaling will keep it charged up and ready to go.
by pdf
Aug 30 2013 9:16am
Forum: E-Bike General Discussion
Topic: Whats normal performance wise?
Replies: 31
Views: 1808

Re: Whats normal performance wise?

pdf, I think you need to refamiliarise yourself with the power capabilities of recent geared hubs. A lot has change. And the very first sentence you posted in this thread led the OP to think you knew precisely about that system. Try to imagine your ezee (I run them also) at twice the power. If you ...
by pdf
Aug 29 2013 3:41pm
Forum: E-Bike General Discussion
Topic: Whats normal performance wise?
Replies: 31
Views: 1808

Re: Whats normal performance wise?

After shorting the black & green wires on the 3 speed switch connector, the speed on the flat has increased to 19 - 20 mph. That was it then - the controller was set to mid speed. All sorted then. From the codes on your motor (1307 = code 13) that means you have a slow(ish) wind motor and 19/20mph ...
by pdf
Aug 29 2013 11:10am
Forum: E-Bike General Discussion
Topic: Whats normal performance wise?
Replies: 31
Views: 1808

Re: Whats normal performance wise?

Yes, that is the motor & controller I have though the main picture is wrong (shows smaller motor). The motor is larger than a geared hub, its about 18cm in diameter, see here: http://www.szbaf.com/product.asp?id=2 if the motor is not the geared hub, then forget comments. The system is clearly diffe...
by pdf
Aug 29 2013 8:36am
Forum: E-Bike General Discussion
Topic: Whats normal performance wise?
Replies: 31
Views: 1808

Re: Whats normal performance wise?

Yes, normal for that power system. Doesn't sound right to me at all, even if the CST is a mid wind speed. Very timid. On a regular code 10 BPM with a KU123 (not shunted) at 36V30 amps you'd expect precisely 34kph in a 700C. And the myth about the BPM being a small hub motor, and KU123 about heat sh...
by pdf
Aug 28 2013 4:27pm
Forum: E-Bike Non-hub Motor Drives
Topic: more efficient hub or mid drive
Replies: 80
Views: 7883

Re: more efficient hub or mid drive

My experience is similar to others. Both my mid-drive and hub setups get about the same average efficiency for day to day driving, around 18 Wh/mile. The mid-drive can be a Wh/mile lower sometimes. Speed is the biggest thing that effects the efficiency I see. If I spend a lot of time over 20 mph (es...
by pdf
Aug 28 2013 4:19pm
Forum: E-Bike General Discussion
Topic: Whats normal performance wise?
Replies: 31
Views: 1808

Re: Whats normal performance wise?

Yes, normal for that power system. In this speed range, the speed is proportional to the voltage. For more help up a hill, you are going to need more power. If your equipment is flaccid, power up! More volts to go faster, more power to go up a hill. Your power can be limited by: 1) the current your ...