Search found 11265 matches

by spinningmagnets
May 12 2021 7:54am
Forum: Bike Mechanical & Structural
Topic: Aluminium Triangle Case build, minimal tools?
Replies: 14
Views: 438

Re: Aluminium Triangle Case build, minimal tools?

Many oysters here, but a few pearls if you look...

"Show us your homemade battery box"
viewtopic.php?f=3&t=12847
by spinningmagnets
May 11 2021 11:47am
Forum: Battery Technology
Topic: Index of flat pouch cell connection methods
Replies: 12
Views: 304

Re: Index of flat pouch cell connection methods

Thanks for posting all of that, DogDipstick. I have heard of spot-welding pouch-tabs together, but I have not tried this myself yet. The reason I havent gone out of my way to try it first hand, is because it would make it more difficult to swap-out a bad cell, which is a major benefit of clamped-tab...
by spinningmagnets
May 11 2021 11:27am
Forum: Battery Technology
Topic: kobalt 24V tool packs (2ah and 4ah)
Replies: 9
Views: 2095

Re: kobalt 24V tool packs (2ah and 4ah)

Bump. Lowes has not been able to get as much adoption of their 24V / 7S line of tools, as they had hoped. I'm hearing reports that their suitcase tool "bundles" are aggressively priced to get weekender handymen to buy into the system. I'm told Milwaukee has a patent on using five lithium c...
by spinningmagnets
May 11 2021 11:14am
Forum: EScooter/EMotorcycle Build Threads
Topic: Golf E-Caddy
Replies: 4
Views: 140

Re: Golf E-Caddy

Just for general information, Kobalt at Lowes uses 24V tool packs, and I think Bosch has 36V packs available for their heavy duty contractor tools.
by spinningmagnets
May 11 2021 7:17am
Forum: EScooter/EMotorcycle Build Threads
Topic: Golf E-Caddy
Replies: 4
Views: 140

Re: Golf E-Caddy

Nicely done! If you try a similar project in the future, consider the option of EGO yard tool batteries. They are marketed as "56V", but they've been disassembled and thoroughly examined, and they are 14S, or what we might call 52V. As such they will operate equipment that labeled 48V, and...
by spinningmagnets
May 10 2021 11:35am
Forum: Battery Technology
Topic: Index of flat pouch cell connection methods
Replies: 12
Views: 304

Re: Index of flat pouch cell connection methods

That sounds like useful info, would you please post some pics?
by spinningmagnets
May 09 2021 9:03am
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 538
Views: 88103

Re: Spot Welding Copper Strips to 18650 Battery Cells

The shells of 18650/21700 cells are typically a steel core with nickel-plating for corrosion resistance.
by spinningmagnets
May 09 2021 8:20am
Forum: Battery Technology
Topic: Index of flat pouch cell connection methods
Replies: 12
Views: 304

Re: Index of flat pouch cell connection methods

Reserved for future data and pics
by spinningmagnets
May 09 2021 7:17am
Forum: Battery Technology
Topic: Index of flat pouch cell connection methods
Replies: 12
Views: 304

Re: Index of flat pouch cell connection methods

A closer look at the Jonescg method A hole-punch jig for tabs that are too thick for a paper hole-puncher https://endless-sphere.com/forums/viewtopic.php?f=31&t=38252&start=375#p1198715 https://endless-sphere.com/forums/download/file.php?id=196558 https://endless-sphere.com/forums/download/f...
by spinningmagnets
May 09 2021 7:17am
Forum: Battery Technology
Topic: Index of flat pouch cell connection methods
Replies: 12
Views: 304

Re: Index of flat pouch cell connection methods

Zappy used a common method of having the tabs touch each other with nothing in-between them, then he folded a thick copper sheet section over the tabs and used three bolts and nuts to clamp the assembly. I'll look for a better pic, but here is an example: https://endless-sphere.com/forums/viewtopic....
by spinningmagnets
May 09 2021 7:16am
Forum: Battery Technology
Topic: Index of flat pouch cell connection methods
Replies: 12
Views: 304

Index of flat pouch cell connection methods

There doesn't seem to be a definitive DIY solution to connecting the tabs on pouch cells, but quite a few ideas. I come across variations when I read about a pack build, so I'd like to collect the types here as a reference and a place of discussion. Today I just found out about the "Termifoil&q...
by spinningmagnets
May 08 2021 9:46am
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 538
Views: 88103

Re: Spot Welding Copper Strips to 18650 Battery Cells

The area of concern is the negative end of the cell. As far as performance, 0.15mm thick copper has the same current-carrying capacity as 0.60mm thick nickel, with a much lower voltage-drop. (4:1 conductivity ratio between copper and nickel) The copper also acts as a heat-sink for the cell. The heat...
by spinningmagnets
May 08 2021 8:04am
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 538
Views: 88103

Re: Spot Welding Copper Strips to 18650 Battery Cells

This is an awesome result! This is a new standard for high amp packs.
by spinningmagnets
May 07 2021 12:50pm
Forum: EBike General Discussion
Topic: DIY candidates
Replies: 11
Views: 287

Re: DIY candidates

I agree.
by spinningmagnets
May 06 2021 6:37pm
Forum: Battery Technology
Topic: Nickel welding strips - current capability ??
Replies: 17
Views: 7125

Re: Nickel welding strips - current capability ??

Current flows in series in a battery pack. A strip that connects one cell to the other might only be one inch long, but...there are 15 of them in a 14S 52V pack. If the controller and motor are drawing 30A, then pass 30A at 52V through 15 inches of nickel strip to see if there is any voltage drop. N...
by spinningmagnets
May 06 2021 6:22pm
Forum: E-Vehicles General Discussion
Topic: Circumference and speed ?
Replies: 5
Views: 139

Re: Circumference and speed ?

180 ___ "X" 215 x 100 = For the two fractions to be equal, you can multiply the cross-located numbers and they will both equal the same number. Therefore...180 x 100 = 18,000 Then, 215 x "X" must equal 18,000 "X" equals 18,000 divided by 215 = 83.7 The smaller tire cir...
by spinningmagnets
May 06 2021 1:42pm
Forum: E-Vehicles General Discussion
Topic: Circumference and speed ?
Replies: 5
Views: 139

Re: Circumference and speed ?

After some thought, I agree.
by spinningmagnets
May 06 2021 6:44am
Forum: E-Vehicles General Discussion
Topic: Circumference and speed ?
Replies: 5
Views: 139

Re: Circumference and speed ?

Convert the tire circumference difference into a percentage, and that percentage will also be the change in speed, with RPM's being the same.
by spinningmagnets
May 05 2021 7:26pm
Forum: General Discussion
Topic: Historic "Deathbike" stolen in Oregon, $1500 reward
Replies: 7
Views: 514

Historic "Deathbike" stolen in Oregon, $1500 reward

Luke Workman, known as Live for Physics / LFP, was storing the "deathbike" in a new facility owned by Luna Cycle in Bend, Oregon.

$1500 reward for it's return.

Image
by spinningmagnets
May 05 2021 10:47am
Forum: EBike General Discussion
Topic: E-bike mid-drive motors hardly outperforms hub motors
Replies: 37
Views: 870

Re: E-bike mid-drive motors hardly outperforms hub motors

After some thought. I realized I dint actually have any experience with 250W hubs or mid-drives, so...please disregard anything I wrote previously.
by spinningmagnets
May 05 2021 10:41am
Forum: EBike Technical
Topic: Same kits, different results. Why?
Replies: 7
Views: 199

Re: Same kits, different results. Why?

Here is a link to the QS 205/50H hubmotor. The website page lists their three most popular kV's, the 3T, 4T, and 5T. The turn-count refers to the copper windings inside, so...they all look the same from the outside. https://www.qsmotor.com/product/3000w-bicycle-motor/ If you contact them, they actua...
by spinningmagnets
May 05 2021 10:13am
Forum: EBike Technical
Topic: Same kits, different results. Why?
Replies: 7
Views: 199

Re: Same kits, different results. Why?

If the battery voltage and tire diameter are the same, then the most likely reason is that he is using a high kV motor (low turn count), on a flat road. The air space around each stator tooth is a fixed size. The could can be made from many turns of thin wire, or a few turns of thick wire. This affe...
by spinningmagnets
May 04 2021 1:30pm
Forum: EBike General Discussion
Topic: building chopper e-bike
Replies: 7
Views: 231

Re: building chopper e-bike

A 16 inch moped rim will seat 20-inch bicycle tires. You might consider chrome spokes and a fat 20-inch tire for a chopper look.

Also contact dr chopper moser on Facebook. He may have the info you want.