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by spinningmagnets
May 17 2021 12:08pm
Forum: Battery Technology
Topic: New battery cells for robot vacuum cleaner Rowenta
Replies: 10
Views: 126

Re: New battery cells for robot vacuum cleaner Rowenta

I'd recommend that you try MJ1 cells from LG for this. Hard to find authentic MJ1's, though...
by spinningmagnets
May 17 2021 12:02pm
Forum: EBike Build Threads
Topic: $600 cad walmart build
Replies: 5
Views: 145

Re: $600 cad walmart build

Amps produce the majority of motor heat, and these motors have run well at 36V. You would have to buy a brushed controller to convert to 36V, along with a 36V battery. You may notice that the SLA batteries will start losing range at a noticeable rate. I would begin saving up for a 36V controller and...
by spinningmagnets
May 17 2021 11:51am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1346
Views: 207356

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

Excellent result. Imho, the 0.10mm copper is adequate for the high-amp 18650's, but there are 21700's that can do bigger amps, so for me, the science says that 0.15mm copper can do it all. Could you please test 0.15mm nickel-plated-steel over 0.15mm copper? Its cheaper, easier to cut, and more readi...
by spinningmagnets
May 17 2021 1:26am
Forum: Battery Technology
Topic: Building a large capacity battery for bicycle trailer
Replies: 29
Views: 288

Re: Building a large capacity battery for bicycle trailer

I don't know about most inexpensive, but...for 100-Ah, I'd use Nissan Leaf cells.
by spinningmagnets
May 16 2021 7:40pm
Forum: Alternative Energy
Topic: Looking into small DIY wind turbines.
Replies: 29
Views: 2543

Re: Looking into small DIY wind turbines.

I recall finding a lot of useful info on DIY wind-gens at otherpower.com, and their chat-forum fieldlines.com The way I remember it, it is useful to buy/rent a data-logging "weather station" that will log wind-speed, direction, and frequency. Build a tall pole, and attach the weather stati...
by spinningmagnets
May 16 2021 7:30pm
Forum: Motor Technology
Topic: .......................
Replies: 24
Views: 618

Re: .......................

Hubsinks do not seem to help much in a standard hubmotor as it is shipped to he customer. However, if you add 10ml of ferrofluid, there is a huge benefit to heat-shedding, and once FF is added, hubsinks boost that effect significantly.
by spinningmagnets
May 16 2021 5:31pm
Forum: Large EV General Discussion
Topic: whats the best/easist type of car to convert to electric?
Replies: 2
Views: 55

Re: whats the best/easist type of car to convert to electric?

Rear wheel drive seems the easiest to me. I've been researching it for a long time, but be aware I haven't done it yet. https://www.electricbike.com/rich-benoit-converts-an-old-skool-rat-rod-to-electric/ A small Chevy S10 pickup truck was converted, and for years it was my go-to conversion to compar...
by spinningmagnets
May 16 2021 5:04pm
Forum: Battery Technology
Topic: Compression of pouch cells, info/data
Replies: 39
Views: 314

Re: Compression of pouch cells, info/data

Awesome info. I stand corrected.

serious_sam, you were correct.
by spinningmagnets
May 16 2021 1:02pm
Forum: Battery Technology
Topic: Compression of pouch cells, info/data
Replies: 39
Views: 314

Re: Compression of pouch cells, info/data

Side note: Here is a graphic that shows my understanding of what a "prismatic" cell is (I referred earlier to prismatic as a "folded pouch cell"). Its relevant to this thread because I don't like that the folded edges would likely have uneven compression, compared to flat pouch c...
by spinningmagnets
May 16 2021 12:40pm
Forum: Battery Technology
Topic: Compression of pouch cells, info/data
Replies: 39
Views: 314

Re: Compression of pouch cells, info/data

https://iopscience.iop.org/article/10.1149/2.1121915jes#f1 Here's a PDF on pouch-cell compression. The cells were tested at "Mega Pascals", which is a pressure comparison to atmospheric pressure. If you add 0.10 MPa to anything that is at sea level, you have doubled the pressure it is und...
by spinningmagnets
May 16 2021 11:57am
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 534
Views: 88512

Re: Spot Welding Copper Strips to 18650 Battery Cells

Discussion of compressing flat pouch cells has been moved to its own thread, found here:

"Compression of pouch cells, info/data"
Spot Welding Copper Strips to 18650 Battery Cells
by spinningmagnets
May 16 2021 11:24am
Forum: Battery Technology
Topic: Compression of pouch cells, info/data
Replies: 39
Views: 314

Compression of pouch cells, info/data

I'm starting this thread to create a reference concerning compression of pouch cells, and moving that existing discussion to here. The benefits and drawbacks of various methods, and the results of various levels of compression. It is generally agreed upon that some compression is "good", b...
by spinningmagnets
May 16 2021 10:20am
Forum: Motor Technology
Topic: Hub motor rewinding, what thickness of enamelled copper wire?
Replies: 67
Views: 1833

Re: ....................................

This thread is temporarily locked for review
by spinningmagnets
May 15 2021 2:38pm
Forum: Battery Technology
Topic: Compression of pouch cells, info/data
Replies: 39
Views: 314

Re: Spot Welding Copper Strips to 18650 Battery Cells

The Battery engineer I spoke to also said, "anything is better than nothing" so apply a sturdy housing as protection, with a modest amount of compression on the flat sides and you are miles ahead of anyone who is just using duct tape to wrap a pack, with no compression at all... Start with...
by spinningmagnets
May 15 2021 10:20am
Forum: EBike General Discussion
Topic: Disaster today, almost set two fires with BBSHD and 52v batteries
Replies: 61
Views: 770

Re: Disaster today, almost set two fires with BBSHD and 52v batteries

I suspect the BMS is damaged, and even if it still "seems to work", I would not trust it.

I still trust XT90 connectors. A shorted bent pin on the other connector is not an indictment against the other connectors. Nothing wrong with Andersons, if they work well for you.
by spinningmagnets
May 15 2021 8:37am
Forum: EScooters/EMotorcycles
Topic: INDEX, motorcycle and scooter E-Conversions
Replies: 36
Views: 1905

Re: INDEX, motorcycle and scooter E-Conversions

I have contacted the builder, Dain Sires, to find the motor, battery, and controller info. I will post it when he responds...

https://m.facebook.com/SSESiresSystemsEngineering/

https://www.youtube.com/watch?v=5ajHx18AqYU

https://www.youtube.com/channel/UCo-oje ... 7EFKpUFNBQ
Emoto30.jpg
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by spinningmagnets
May 15 2021 8:04am
Forum: Health and Food
Topic: Can melatonin stop midnight hunger? But it can raise fasting glucose -post 3
Replies: 6
Views: 58

Re: Can melatonin stop midnight hunger?

I occasionally take some melatonin when I need a good night's sleep for an important event the next day, or if hard work will be required (*once every two weeks?). Concerning any supplement, I'd recommend starting with a low dose and slowly raise it to find the minimum dose to get the desired effect...
by spinningmagnets
May 15 2021 7:57am
Forum: Battery Technology
Topic: Compression of pouch cells, info/data
Replies: 39
Views: 314

Re: Spot Welding Copper Strips to 18650 Battery Cells

EDIT: 3-8 psi This is the correct number. xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Are there any published or derived specs on the compression pressure - too much is probably as bad as none I communicated to a battery engineer from Zero motorcycles and and XXX-PSI is a helpful goal. They used flat...
by spinningmagnets
May 14 2021 8:33pm
Forum: Battery Technology
Topic: "Copper/nickel sandwich" buses for series connections
Replies: 61
Views: 4541

Re: "Copper/nickel sandwich" buses for series connections

The tabs on pouch cells are typically aluminum for the positive, or sometimes nickel-plated aluminum. The negative tabs are copper core with nickel-plating. The nickel is to reduce oxidation, but I think if you put an additional nickel strip along both sides, and pinch them with the spot-welding pro...
by spinningmagnets
May 12 2021 7:54am
Forum: Bike Mechanical & Structural
Topic: Aluminium Triangle Case build, minimal tools?
Replies: 14
Views: 485

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: 13
Views: 375

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: 2108

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: 180

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.