Search found 11012 matches

by spinningmagnets
Sep 25 2020 4:20pm
Forum: Battery Technology
Topic: MJ1 vs 30Q for my needs?
Replies: 9
Views: 162

Re: MJ1 vs 30Q for my needs?

$500 52V (5P, 10A X 5 = 50A) 17.5ah LG MJ1 $400 52V (5P, 15A X 5 = 75A) 15ah Samsung 30Q Both packs will easily supply the 30A max that the stock BBSHD draws. They are both the same physical size. Personally I would get the cheaper pack (30Q), because I am surprised there is that big of a difference...
by spinningmagnets
Sep 23 2020 10:14am
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 362
Views: 62461

Re: Spot Welding Copper Strips to 18650 Battery Cells

It's my understanding that Makita and others use nickel-plated copper so that the nickel provides corrosion protection, The nickel is thin, and does not help the welding. These manufacturers often use a laser-welding process, with a very expensive and fast machine.
by spinningmagnets
Sep 23 2020 10:12am
Forum: E-Vehicles General Discussion
Topic: Question for engineers and EV geeks: What are the advantages for a car being designed as a BEV only?
Replies: 19
Views: 2162

Re: Question for engineers and EV geeks: What are the advantages for a car being designed as a BEV only?

I was quite disappointed when GM discontinued the Chevy Volt. My son has one and we are both impressed by it. Most daily journeys for one member of the family are typically short. One example is that my spouse worked 8 miles from our home, so 16 miles each day, five days a week. Of course on week-en...
by spinningmagnets
Sep 23 2020 8:48am
Forum: Battery Technology
Topic: Tesla battery day announcement
Replies: 34
Views: 845

Re: Tesla battery day announcement

I currently have a 1991 Toyota 4-cyl truck, 170K miles (I am the second owner), and I have owned several older cars in my past. The tires, brakes, shocks, wheel bearings, and suspension joints will "wear out" the same on an EV compared to a gasoline car. When restoring an older classic car, the gas ...
by spinningmagnets
Sep 20 2020 2:23pm
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 362
Views: 62461

Re: Spot Welding Copper Strips to 18650 Battery Cells

I can only speculate as to why the copper/nickel sandwich works, but...for some reason it works.
by spinningmagnets
Sep 20 2020 7:50am
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 362
Views: 62461

Re: Spot Welding Copper Strips to 18650 Battery Cells

Easy to test, but...I sold my kWeld, and I don't need any more battery packs, I have three. To connect the two end collectors (2mm copper bar for this example) to the cells, I suggest you bond the 2mm bar to a strip of 0.20mm copper foil using a $50 DIY MOT-welder... https://www.electricbike.com/res...
by spinningmagnets
Sep 20 2020 7:31am
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 362
Views: 62461

Re: Spot Welding Copper Strips to 18650 Battery Cells

One example of infinite-slot. The copper in one strip is not touching the copper in the other strip. These would be flipped over so the copper is the only part actually touching the cell-tip. A dab of glue in the center of the strip holds it in place onto the nickel bus. Here, the copper handles the...
by spinningmagnets
Sep 20 2020 7:22am
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 362
Views: 62461

Re: Spot Welding Copper Strips to 18650 Battery Cells

1200 amps from the 38P You only need thick copper buses at the two pack ends, the positive and negative collectors. You are only drawing 31A per cell, so 0.20mm thick copper is all you need for the cell buses. Making those buses thicker will not help, and it would make welding more difficult. If yo...
by spinningmagnets
Sep 20 2020 6:51am
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 362
Views: 62461

Re: Spot Welding Copper Strips to 18650 Battery Cells

In the sandwich method, the copper melts onto the cell (you can Dremel across the center of a weld to see the cross-section). The cell end is nickel-plated steel, both have high resistance. When you place a probe on that material and send a pulse through it to something that is conductive on the oth...
by spinningmagnets
Sep 19 2020 1:29pm
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 362
Views: 62461

Re: Spot Welding Copper Strips to 18650 Battery Cells

If you've already ordered the kWeld, I would suggest that you simply try it out and see how it goes. You might be surprised. That being said, the 0.15mm copper and 0.15mm nickel have been welded with success onto 18650 cells with the kWeld, using the "copper/nickel sandwich" method... Since copper i...
by spinningmagnets
Sep 18 2020 4:29pm
Forum: Stand-up E-scooters and E-skateboards
Topic: Waterproofing electric scooter battery compartment.
Replies: 6
Views: 124

Re: Waterproofing electric scooter battery compartment.

Zero motorcycle batteries are fully potted, along with the Luna Wolf ebike pack. It's a bold risk. However, if you use quality components, and thoroughly test the pack before putting, it provides the absolute best water-proofing and shock-proofing possible.
by spinningmagnets
Sep 17 2020 4:39pm
Forum: Battery Technology
Topic: Pack Died From Standing 2 Month?
Replies: 18
Views: 586

Re: Pack Died From Standing 2 Month?

I'd bet it's a couple bad cells self-discharging, or...a BMS failure
by spinningmagnets
Sep 15 2020 2:58pm
Forum: E-Bike General Discussion
Topic: 52 volt batteries proceed with caution
Replies: 26
Views: 769

Re: 52 volt batteries proceed with caution

My first pack was 52V from EM3EV, at the time, their 14S packs were called 50V. No problems. I now have three packs from Luna, all 52V, all of them work fine, none have given me any problems. I'd still have the first pack, but a co-worker took a test-ride and made me an offer for much more than the ...
by spinningmagnets
Sep 15 2020 2:50pm
Forum: E-Bike General Discussion
Topic: Is DIY dying?
Replies: 33
Views: 831

Re: Is DIY dying?

I'm sure that there are some niches that are not yet being served, but...the last few years it seems like the low-hanging fruit has been picked. Mid-drives that are installed by the bike owner is booming, and turn-key ebikes are booming. Not much left to develop that would have a broad enough market...
by spinningmagnets
Sep 13 2020 1:50pm
Forum: E-Bike Technical
Topic: Is regenerative braking really worth anything?
Replies: 95
Views: 1962

Re: Is regenerative braking really worth anything?

If you live where your commute takes you across a big and long downhill, regen will make your brake pads last much longer, and also it will keep the pads cool so that if you ever need them, they are not in an overheated condition where they would fail just when you need them most. As far as how many...
by spinningmagnets
Sep 11 2020 1:17pm
Forum: Battery Technology
Topic: Avoiding spot welding - Using magnets?
Replies: 11
Views: 956

Re: Avoiding spot welding - Using magnets?

I agree with air circulation around cells. It doesnt seem to be a huge concern in the ebike community, based on how many still build with hot-glue. If you use high-amp cells, and a large enough P-group, then pulling average amps will result in a cool-running pack. Sadly, many still pull high amps fr...
by spinningmagnets
Sep 11 2020 11:35am
Forum: Large EV General Discussion
Topic: EKartGo Project
Replies: 18
Views: 800

Re: EKartGo Project

The kWeld is perfect for welding the nickel onto the cell-ends, but...To weld the nickel onto a thick copper bus-plate, I would recommend a 1500W RSU as a spot-welder. Surprisingly affordable and easy to make. Timing is not critical, so a simple foot-switch works well. I can mail you a 1500W transfo...
by spinningmagnets
Sep 11 2020 11:17am
Forum: Battery Technology
Topic: Avoiding spot welding - Using magnets?
Replies: 11
Views: 956

Re: Avoiding spot welding - Using magnets?

This is one of the options I drew in the magnet thread. The common plastic cell-holders have slots that would hold the strips inline, but between the two cells in series, I suppose you could add a "crinkle" to act as an expansion joint. "Magnets holding copper bus onto cell, no-weld no-solder" https...
by spinningmagnets
Sep 11 2020 9:29am
Forum: Battery Technology
Topic: Avoiding spot welding - Using magnets?
Replies: 11
Views: 956

Re: Avoiding spot welding - Using magnets?

The expansion of circumference is negligible and it can be taken up my stretch in the materials of the framework. Meaning, it wont cause cracks in the framework, or cause issues with contact between the cells and the magnet/copper-buses. I don't know how much the length would expand, maybe only one ...
by spinningmagnets
Sep 10 2020 9:05pm
Forum: Battery Technology
Topic: Avoiding spot welding - Using magnets?
Replies: 11
Views: 956

Re: Avoiding spot welding - Using magnets?

You can use any method you want on the positive tip. Spot-welding buses wont hurt it at all. You can solder to it also, and if heat makes you nervous, you can solder just a thin fuse-wire onto the positive tip, which can be done so fast and so easily that there is no concern about heat. You can even...
by spinningmagnets
Sep 09 2020 4:02pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1193
Views: 170174

Re: kWeld - "Next level" DIY battery spot welder

If you are connecting copper to nickel, and there is no cell involved , you might want to consider a microwave-oven-transformer / MOT...I found several 1500W units for free, and if you pay shipping I will send you one. "Making a Resistance Soldering Unit, and maybe a spot-welder too" https://www.ele...
by spinningmagnets
Sep 07 2020 5:45am
Forum: Battery Technology
Topic: DIY spot-welder, transformers from microwave ovens?
Replies: 69
Views: 14894

Re: DIY spot-welder, transformers from microwave ovens?

There's a lot of innovation going on, and a MOT-based welder is very adjustable. If using a single large MOT, a garage-builder can get 1500W of power from a common wall socket. I have a kWeld, and it is very useful for a specific job. Its a precision timer that uses a battery for the current (a car ...
by spinningmagnets
Sep 05 2020 12:41pm
Forum: E-Bike Technical
Topic: Where To Buy 5AWG Silicone Wire?
Replies: 5
Views: 182

Re: Where To Buy 5AWG Silicone Wire?

Please post if you find a source. Perhaps until then, maybe run paired 8AWG to equal the same cross section?
by spinningmagnets
Sep 04 2020 8:40pm
Forum: E-Bike General Discussion
Topic: Middrive vs hub acceleration
Replies: 28
Views: 578

Re: Middrive vs hub acceleration

On flat ground, I'd use a hubmotor to get hard acceleration. I have a mid drive and a hub. I plan to keep them both, each has its benefits and drawbacks. If I was building a bike for an acceleration contest, I'd use 2WD and fat tires on smaller rims. Rear hubmotor and a front geared hub. If I was ru...
by spinningmagnets
Sep 02 2020 8:34pm
Forum: E-Vehicles General Discussion
Topic: ES member "Farfle", RIP at 27
Replies: 4
Views: 657

ES member "Farfle", RIP at 27

It is with great sadness that we announce the death of our friend, Jackson Edwards. https://www.electricbike.com/ev-pioneer-jackson-farfle-edwards-rip/ Here is his electric bike, that he posted in Aug of 2010, when he was just 17 https://endless-sphere.com/forums/viewtopic.php?f=6&t=20497 Here is hi...