Search found 913 matches

by mvly
Jul 27 2014 12:48pm
Forum: EBike General Discussion
Topic: Overstating Specs?
Replies: 16
Views: 924

Re: Overstating Specs?

43mph is the unloaded speed I suspect. So loaded speed would be much closer to 35mph MAX on flat with no headwind for reasonable weight person.

Just know what you are buying. So I don't see any false advertising here. They just don't mention what those conditions are for the 43mph.
by mvly
Jul 27 2014 12:42pm
Forum: Battery Technology
Topic: Trusted and Reliable companies list for batteries
Replies: 57
Views: 15042

Re: Trusted and Reliable companies list for batteries

HobbyKing is NOT trusted and reliable at all. Avoid if possible. If you need toys from then go for it. Battery? I would stay away. Got their nanotech and after 2 years and around 300 cycles they are shit. I get like 1/2 capacity now. I am too cheap to toss them out. So I am using them in lower power...
by mvly
Jul 22 2014 12:56am
Forum: Battery Technology
Topic: Nissan Leaf Cells Test Data
Replies: 386
Views: 85994

Re: Nissan Leaf Cells Test Data

I just got a leaf, and I'm trying to figure out the economics of their 60,000 mile battery warranty (if pack goes below 70%, they will replace). Strangely, 60,000/65 (avg trip of 65) yields ~1000 cycles. Looking at other nmc like sony vtc4, if you project the cycle life data for ~4C you get 70% cap...
by mvly
Jul 18 2014 8:06pm
Forum: Items for Sale - New
Topic: Vector e-bike and Parts / WORLDWIDE
Replies: 2373
Views: 394360

Re: Vector. New 5.4 kW ebike from scratch.

Posting a comment as requested :P I agree with snellemin, the dual shock looks odd and isnt really necessary. You've saved weight elsewhere, it's silly to waste it on a second shock. I like the carbon bits and the little 'window' in some of the pics higher up looks good to break up the frame. I thi...
by mvly
Jul 18 2014 7:25pm
Forum: EBike Technical
Topic: Did I burn up my hs3540
Replies: 13
Views: 1381

Re: Did I burn up my hs3540

Not sure about your motor, but my TC-80 motor regularly goes over 100C. Sometime it hits 142C. But it cools off pretty quick. So far it is still fine. The hall sensors are rated for 150C max temperature if they are legit SS41 hall sensor. Maybe your motor have crappy or fake SS41 hall sensors and he...
by mvly
Jul 17 2014 9:49am
Forum: Battery Technology
Topic: Zippy Compact 35C cells overrated!
Replies: 60
Views: 6588

Re: Zippy Compact 35C cells overrated!

For comparison, I have the nanotech 25C 10s5Ah. IT has around 200 cycles before 2 packs started to die. The rest was ok but sagged a lot more than when new. Replaced the 2 bad packs and everything was good again. The new pack is keeping the old one from sagging too much. Now I am around 300 cycles n...
by mvly
Jul 15 2014 5:02pm
Forum: Battery Technology
Topic: Panasonic NCR18650B 2.7kWhr pack for my Stealth Bomber
Replies: 19
Views: 5891

Re: Panasonic NCR18650B 2.7kWhr pack for my Stealth Bomber

I thought that stealth bomber runs on 24s lifepo4. If so you would need 20s for the same voltage as the stealth bomber. I think the fighter is running on 48V pack.

So did you purposely run lower voltage on the bomber or do you have a stealth fighter?

BTW, nice battery build.
by mvly
Jul 15 2014 1:23pm
Forum: Battery Technology
Topic: Conductivity improving grease project
Replies: 109
Views: 15531

Re: Conductivity improving grease project

OK I went ahead and did some calculation and research in terms of conductivity of material. I think the consensus on the information I found is these SWCNT (Single-Walled Carbon Nano Tube) @ 75% purity are typically 1.5-2x more conductive compared to silver... maybe. Silver cost per gram today: $0.6...
by mvly
Jul 13 2014 1:15pm
Forum: EBike General Discussion
Topic: eBike Yellowstone National Park
Replies: 22
Views: 3038

Re: eBike Yellowstone National Park

Wow nice Yosemite vid on ebike.

I am assuming stealth bomber?

Now if you can get to Yosemite just on you ebike. : ) that is my goal. No need for truck or car or other vehicles. Just ebike it all the way there and back!
by mvly
Jul 13 2014 11:32am
Forum: Battery Technology
Topic: Conductivity improving grease project
Replies: 109
Views: 15531

Re: Conductivity improving grease project

I am going to practice wait and see approach. Too many news about break through these day. We will have to see what Luke can come up with and to see if it is reasonably priced. Usually with these break through the inventors want some price for it which is ultimately passed to the consumer. Heck if t...
by mvly
Jul 13 2014 10:18am
Forum: Battery Technology
Topic: Conductivity improving grease project
Replies: 109
Views: 15531

Re: Conductivity improving grease project

I have recent had a talk with some researcher (about a year ago) who was working on carbon nanotube as conductors and other uses. He said using a small strand, you can essentially replace a 12-14 gauge copper wire. I thought this is great, considering most hub motor have weaker axle and such caused ...
by mvly
Jul 10 2014 4:25pm
Forum: Items for Sale - New
Topic: Vector e-bike and Parts / WORLDWIDE
Replies: 2373
Views: 394360

Re: Vector. New 5.4 kW ebike from scratch.

I think those are all the comments I have for the ebike itself. The rest looks rock solid. EDIT: a few more: 1) Get Tekro E-Hydraulic ebrakes. Still Hydraulic, but have built in reed sensor to engage regen. I think the button is a pretty crappy solution because when you want to brake you don't press...
by mvly
Jul 05 2014 10:25pm
Forum: Items for Sale - New
Topic: Vector e-bike and Parts / WORLDWIDE
Replies: 2373
Views: 394360

Re: Vector. New 5.4 kW ebike from scratch.

:twisted: Wow if you can get it to $5-6K USD that would put Stealth out of business! That is how much it cost me to build my 5KW ebike. Though it probably have a lot more battery capacity than this ebike. Good luck and looking forward to the kick starter campaign! Here is my recommendations: 1) can ...
by mvly
Jul 05 2014 10:17pm
Forum: Battery Technology
Topic: Nissan Leaf Cells Test Data
Replies: 386
Views: 85994

Re: Nissan Leaf Cells Test Data

Yikes! The more I see these open-can packs the more I'm glad I left mine inside the cans. Not only do you get a bit of safety by the cells and their connectors being sheilded from physical damage, but you also get the original bolt holes to apply compressive force. http://i.imgur.com/Qu26sDj.jpg I ...
by mvly
Jul 03 2014 8:37pm
Forum: Battery Technology
Topic: Nissan Leaf Cells Test Data
Replies: 386
Views: 85994

Re: Nissan Leaf Cells Test Data

Well you can't fault USPS. Technically these guys shouldn't even be shipping them USPS.

But yeah that battery looked like it was poorly put together.

I say from now on just get those still in its case. Less chance of short and damage.
by mvly
Jul 03 2014 12:06am
Forum: EBike General Discussion
Topic: Brizzly leaning e-trike
Replies: 5
Views: 879

Re: Brizzly leaning e-trike

Need to go 50mph+ before I consider getting this. All kidding aside. This looks like a good design and a good way to hit up the local market for grocery and such. Pair it with a shitty looking bike and it should deter the thieves making this very useful for everything. Also why not just make it dual...
by mvly
Jul 02 2014 2:59pm
Forum: Battery Technology
Topic: Nissan Leaf Cells Test Data
Replies: 386
Views: 85994

Re: Nissan Leaf Cells Test Data

Hi, yopappamon scored a Volt pack: http://endless-sphere.com/forums/viewtopic.php?f=34&t=60460&p=915109#p914753 I'm not sure how he found it originally, but it ended up on ebay before we had a chance to close a deal. $1,400 plus $360 freight. Still over a grand cheaper than new lead. Wonder...
by mvly
Jul 01 2014 1:58pm
Forum: EBike General Discussion
Topic: Why do I keep blowing tire tubes @ 30mph...
Replies: 23
Views: 2119

Re: Why do I keep blowing tire tubes @ 30mph...

I use double layer cloth rim tape. Never had a problem after that. I also run a tufty lining and thick thorn resistance tube with slim inside it.
by mvly
Jul 01 2014 10:31am
Forum: EBike Technical
Topic: "Portable" charger for Leaf batteries?
Replies: 17
Views: 1678

Re: "Portable" charger for Leaf batteries?

I think you should look carefully at how to proceed in building this 14s1p. Lets start from what you are given: 1) You want 14s1p. --- The only way you can get this is to separate the cells into individual cells and then wire it up to 14s1p. 2) You want 2 packs of 14s1p. --- The only way you can get...
by mvly
Jun 30 2014 5:00pm
Forum: EBike Technical
Topic: "Portable" charger for Leaf batteries?
Replies: 17
Views: 1678

Re: "Portable" charger for Leaf batteries?

Is there a BMS that would allow me to bulk charge the whole 14s2p pack at once? One charger, one plug? Just search eBay. They are not the best, but you can get a a14s BMS for reasonable price. Here is one. http://m.ebay.com/itm/161348820310?nav=SEARCH Though I never have experience with these selle...
by mvly
Jun 30 2014 11:28am
Forum: EBike Technical
Topic: "Portable" charger for Leaf batteries?
Replies: 17
Views: 1678

Re: "Portable" charger for Leaf batteries?

Forget 15s, since 16s means you won't have to fool with the modules at all, just connect them in series. You mean connect the entire pack in series? For 125v or so? I've actually considered dialing back to 14s2p and leaving the remaining packs in storage as backups. That way I could get the Grin Cy...
by mvly
Jun 30 2014 2:14am
Forum: Battery Technology
Topic: Battery Care
Replies: 13
Views: 1310

Re: Battery Care

Assuming you have legit lifepo4 cells they can be charge and discharged fully many times. Leaving them fully charged doesn't seem to degrade them. I think this only applies to li-co or li-mn. The reason being is lifepo4 bleeds off the upper 0.3V fairly quickly from 3.65V. Most of the time even when ...
by mvly
Jun 30 2014 1:05am
Forum: Battery Technology
Topic: Nissan Leaf Cells Test Data
Replies: 386
Views: 85994

Re: Nissan Leaf Cells Test Data

mvly, do you keep your cells under compression, and if so how are you applying the compression force? I am not applying any force at all. I do keepisode the pack together though. Expect a relatively short life then. Nissan goes to a lot of trouble applying an even force of compression across the fa...
by mvly
Jun 29 2014 4:46pm
Forum: Battery Technology
Topic: Nissan Leaf Cells Test Data
Replies: 386
Views: 85994

Re: Nissan Leaf Cells Test Data

John in CR wrote:mvly, do you keep your cells under compression, and if so how are you applying the compression force?
I am not applying any force at all. I do keepisode the pack together though.
by mvly
Jun 29 2014 1:56am
Forum: Battery Technology
Topic: Nissan Leaf Cells Test Data
Replies: 386
Views: 85994

Re: Nissan Leaf Cells Test Data

Mvly, When you say storage temperature, do you have a degree range in mind?? I have a refrigerator downstairs that could be purpose set to the ideal temp.... I am in no way an expert on this, but the consciences on this subject is to keep it below room temperature (25 degree Celsius) but higher tha...