Search found 728 matches

by zzoing
Mar 13 2020 1:11am
Forum: E-Bike Technical
Topic: eBike Battery range efficiency question 48v vs. 72v?
Replies: 20
Views: 1920

Re: eBike Battery range efficiency question 48v vs. 72v?

That's weird! I thought that the 72V went straight to the motor, else it wouldn't make sense to use 72v otherwise? The motor gets hot while climbing, so driving it with 72V would reduce the amp rating for the same power output, the hub would get hot slower at 72v. Why would the controller change a 7...
by zzoing
Mar 05 2020 9:20am
Forum: Battery Technology
Topic: Just found 2000 LiFePo 18650 cells in the recycler
Replies: 9
Views: 669

Re: Just found 2000 LiFePo 18650 cells in the recycler

Hey thanks, I just checked all the safety videos for LiFe battery short circuits and nailgun tests, The short triggered the safety, and the nailgun made the pack warm and smokey, although there weren't flames. I went to get another 35 kilos of them, and in the end my arm was not long enough to reach...
by zzoing
Mar 04 2020 10:35am
Forum: Battery Technology
Topic: Just found 2000 LiFePo 18650 cells in the recycler
Replies: 9
Views: 669

Re: Just found 2000 LiFePo 18650 cells in the recycler

Yes, good idea. I think i'll go round and get another 2000 this evening if they are still there... The first test was a 1600mAh battery, it came in at 1634 on accucell, only from 3.6 to 2.8 at 1C ... cool!
by zzoing
Mar 04 2020 6:08am
Forum: Battery Technology
Topic: Just found 2000 LiFePo 18650 cells in the recycler
Replies: 9
Views: 669

Re: Just found 2000 LiFePo 18650 cells in the recycler

Hey cool advice! thanks for the directions. I'm just checking one of the 2018 cells at 0.7 amps / 0.5C charge, If they have more than 80% of their original value it would be worth going up to get 4000 of them to give/sell to people doing their camper vans and things. I have two bags with about 1000 ...
by zzoing
Mar 03 2020 10:11pm
Forum: E-Bike Technical
Topic: 9C Continents Fat Bike Axle mod 175mm + shop press?
Replies: 2
Views: 532

Re: 9C Continents Fat Bike Axle mod 175mm + shop press?

Sounds cool. Can you please provide some hyperlinks?
by zzoing
Mar 03 2020 9:50am
Forum: Battery Technology
Topic: Just found 2000 LiFePo 18650 cells in the recycler
Replies: 9
Views: 669

Just found 2000 LiFePo 18650 cells in the recycler

I went to the recycler place to throw out a hifi and I found that there is half a bin full of brand new looking lithium batteries unwelded dated 2015 to 2019 1500 to 1800mA... It's from a company that does a bunch of lithium outfitting near where I live. I'd feel like an idiot if I let 2000 batterie...
by zzoing
Feb 18 2020 5:33am
Forum: E-Bike Technical
Topic: 9C Continents Fat Bike Axle mod 175mm + shop press?
Replies: 2
Views: 532

9C Continents Fat Bike Axle mod 175mm + shop press?

Can I re-fit a 9C hub with a 175mm rear axle for a fatbike?

Where can I find the right 175mm axle?

What about derailleur and cog alignment?

Is there a way to offset the freewheel and the disk threads?
by zzoing
Jan 28 2020 10:23pm
Forum: E-Bike General Discussion
Topic: Suspension Wheel with pneumatic-spokes!!! Checkit!!!
Replies: 6
Views: 717

Suspension Wheel with pneumatic-spokes!!! Checkit!!!

Very awesome!!! 10 inch of travel is cooler, although it's good to think in other ways! https://i.imgur.com/744mJVW.gifv
by zzoing
Dec 26 2019 4:31pm
Forum: Battery Technology
Topic: potting compound for batteries
Replies: 34
Views: 2226

Re: potting compound for batteries

You can find boron nitride fairly easily online, I think it's the thermal conductor they mostly use for commercial potting mix. Also recipes online probably. https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313.TR3.TRC0.A0.H0.Xboron+nitride.TRS0&_nkw=boron+nitride&_sacat=0 here's a ...
by zzoing
Nov 08 2019 11:44pm
Forum: E-Bike General Discussion
Topic: New hubs with magnet orientations like Tesla Raven powertrain?
Replies: 3
Views: 387

Re: New hubs with magnet orientations like Tesla Raven powertrain?

Ah that's very interesting. The model 3 technology does also bring in a major efficiency advantage, i've heard figures of 96-97%. The raven edition of the model S using the hallbach technology has 10% higher range. Especially on highways at speeds higher than 80-100mph, the previous motor was strugg...
by zzoing
Nov 08 2019 12:32pm
Forum: E-Bike General Discussion
Topic: New hubs with magnet orientations like Tesla Raven powertrain?
Replies: 3
Views: 387

New hubs with magnet orientations like Tesla Raven powertrain?

The new motor from Tesla's Model 3, called the raven, uses complex magnet orientation to raise motor efficiency from 92 to 96-97%, allegedly.

Do you know if an motorbike and ebike motor companies will copy the idea, to have ebike motors that are twice as efficient as previous versions?
by zzoing
Sep 27 2019 3:51am
Forum: E-Bike General Discussion
Topic: Carbon-Fiber Torque Arm
Replies: 0
Views: 395

Carbon-Fiber Torque Arm

Hey folks, I have figured out how to make a carbon fiber torque arm. Some of you have probably previously welded one of these and think "duh that's obvious I already did that"... it took me ages to figure out that this is the best way. Advantage : Micron accuracy, efficient with time, can be glued s...
by zzoing
Aug 03 2019 7:47pm
Forum: Battery Technology
Topic: Need Charger Recommendation
Replies: 14
Views: 557

Re: Need Charger Recommendation

Tumich has cells on this forum. Bms is recommended for low voltage detect also by the way. They are cheap vheck alixpress.
by zzoing
Aug 03 2019 7:43pm
Forum: Battery Technology
Topic: How to brake using electric motor?
Replies: 5
Views: 459

Re: How to brake using electric motor?

You need a specific controller for the brushed motor which has regen. The regen resistance may be variable. A high level can stop a vehicle on a medium slope say 7%. Its a complement for standard brakes.
by zzoing
Aug 03 2019 2:40am
Forum: Battery Technology
Topic: Need Charger Recommendation
Replies: 14
Views: 557

Re: Need Charger Recommendation

You can buy bms which have an led for every group but they draw current at idle. You can use a spare bms 15pin molex and wired soldered to the cells and check the pins if you are worried. You can find/ make 14 volt cubes for 14 usd and place them on a 15pin molex .Everyone, even noobs, uses a bms. U...
by zzoing
Aug 03 2019 2:35am
Forum: Battery Technology
Topic: 52V battery dropped to 3.3v output, what to check?
Replies: 11
Views: 612

Re: 52V battery dropped to 3.3v output, what to check?

Just take care not to short the metals and measure all the bits you can see... you will get an idea. If you can find the first group with battery negatives, on the end, thats -, andcsearchbyour way up from there with the meter, it shout go 3.5-7-10-13 multiples of 52/13 or whatever.
by zzoing
Jul 31 2019 1:52pm
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1649
Views: 236454

Re: Thread for new battery breakthrough PR releases

It's faster to dig lithium reserves than build battery factories so the price of raw lithium has dropped recently because mining activity is high.
by zzoing
Jul 30 2019 3:18am
Forum: Battery Technology
Topic: 18650 flammability by a shell vaporizing test
Replies: 4
Views: 318

18650 flammability by a shell vaporizing test

I set fire to a a Sanyo cell from 2018 in a controlled environment, I melted through the steel using a 100A current, by placing some battery terminals on either side of the negative terminal. The battery flashed as the steel and copper vaporized, and then it started burning the lithium inside. It wa...
by zzoing
Jul 29 2019 9:59pm
Forum: Battery Technology
Topic: best fireproof case/ system or DIY to store/charge lipo liion safest way
Replies: 42
Views: 2121

Re: best fireproof case/ system or DIY to store/charge lipo liion safest way

those are interesting links thx for that . correct me if i im wrong but adding cement is just so that the metal do not turn red right or( transfer heat to adjescent battery right if multiple pack)? the amout of flames that would go out in the end woud be the same as if put in the amo bow without ce...
by zzoing
Jul 29 2019 9:29pm
Forum: Battery Technology
Topic: best fireproof case/ system or DIY to store/charge lipo liion safest way
Replies: 42
Views: 2121

Re: best fireproof case/ system or DIY to store/charge lipo liion safest way

those are interesting links thx for that . correct me if i im wrong but adding cement is just so that the metal do not turn red right or( transfer heat to adjescent battery right if multiple pack)? the amout of flames that would go out in the end woud be the same as if put in the amo bow without ce...
by zzoing
Jul 29 2019 9:17am
Forum: Battery Technology
Topic: best fireproof case/ system or DIY to store/charge lipo liion safest way
Replies: 42
Views: 2121

Re: best fireproof case/ system or DIY to store/charge lipo liion safest way

is this the exact title or just words of searching that came to your mind cause i see alot of vid but none with fireplaceinsulator in the list it gives me. Sorry I thought that they were easier to find. maybe it was "battery bunker" ... steel box lined with thermal plasterboard, pyrocrete, refracti...
by zzoing
Jul 28 2019 7:03am
Forum: Battery Technology
Topic: best fireproof case/ system or DIY to store/charge lipo liion safest way
Replies: 42
Views: 2121

Re: best fireproof case/ system or DIY to store/charge lipo liion safest way

check youtube for "make a lithium charging box" fireproof... Steel box with high temperature fireplace insulator bricks, vents, and a smoke alarm on top. total budget - 35.
by zzoing
Jul 14 2019 8:23pm
Forum: Battery Technology
Topic: Best cheap spotwelder?
Replies: 19
Views: 2080

Re: Best cheap spotwelder?

Have just found this funny welder from China. Looks pretty crazy. https://www.aliexpress.com/item/3282464 ... 55b7YiGTF2
by zzoing
Jun 26 2019 2:29am
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1649
Views: 236454

Re: Thread for new battery breakthrough PR releases

Cool concept! Perhaps they have flown it for a minute, that would be cool too. BMW has signed something with them, although i am skeptical. It has to fly and land precisely with 5 motors, and have same energy as 5 roadsters to fly for just 2 hours, 420kwh, so every fuel cell is at least a 75kwh fuel...