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by spinningmagnets
Oct 22 2018 7:03pm
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 187
Views: 25028

Re: Spot Welding Copper Strips to 18650 Battery Cells

The design that I am currently impressed by is a broad sheet of copper as a bus-plate, with round holes over the cell locations. The connection between the copper bus-plates and the cell could initially be nickel, and depending on how experiments progress, possibly nickel-plated copper..
by spinningmagnets
Oct 22 2018 4:01pm
Forum: Motor Technology
Topic: Switched Reluctance Motors
Replies: 49
Views: 3930

Re: Switched Reluctance - Ideal for DD Hubs?

"...their biggest drawback (IMO) is the slight loss of efficiency due to a lack of an intrinsic field..." I am still learning, but apparently some motor design engineers agree, since I found some hybrid designs which emphasized the Reluctance phenomenon, but also added some small PM's. Sometimes it ...
by spinningmagnets
Oct 21 2018 5:41pm
Forum: Items for Sale - Used
Topic: Luna Mighty Mini 52v battery - Sunnyvale, CA
Replies: 3
Views: 484

Re: Luna Mighty Mini 52v battery - Sunnyvale, CA

I am a big fan of 48V/52V packs, partially because they can run an inverter during an emergency power outage. The 30Q is rated for 15A, and the 2P mighty mini would be 30A. If we take that as its peak, and use half that as its continuous, it produces 1600W peak, and 800W continuous. I would be comfo...
by spinningmagnets
Oct 21 2018 5:09pm
Forum: Motor Technology
Topic: Switched Reluctance Motors
Replies: 49
Views: 3930

Re: Switched Reluctance - Ideal for DD Hubs?

Ha ha! I am at work, and I'll post the references and pics soon. I have limited options from my ancient smart phone, and the desktops at work are also very restricted as to what I can do on them. LFP mentioned in a thread a short while ago that Switched Reluctance (SR) is where the big players are p...
by spinningmagnets
Oct 21 2018 12:22pm
Forum: Motor Technology
Topic: Switched Reluctance Motors
Replies: 49
Views: 3930

Re: Switched Reluctance Motors

This seems to be the largest thread for "Switched Reluctance" on ES. So rather than start a new thread, I'd like to park some info I found on SR motors here...
by spinningmagnets
Oct 20 2018 9:39am
Forum: E-Bike Non-hub Motor Drives
Topic: Onemotor friction drive
Replies: 1
Views: 206

Re: Onemotor friction drive

This is the same company that was formerly known as "Share-Roller". This second version is the result of feedback from customers.

https://www.electricbike.com/sharerolle ... ion-drive/
by spinningmagnets
Oct 18 2018 9:45pm
Forum: Battery Technology
Topic: Battery Pack Questions (new to this stuff)
Replies: 5
Views: 221

Re: Battery Pack Questions (new to this stuff)

It's also quite easy to make two 4S packs, and then connect them in series. I feel that doing that can be much simpler.
by spinningmagnets
Oct 18 2018 5:16pm
Forum: E-Bike Technical
Topic: Hub motor selection guidance: 3kw unbranded vs 5kw QS
Replies: 29
Views: 1033

Re: Hub motor selection guidance: 3kw unbranded vs 5kw QS

Once you are committed to a 3-kW build, it will never be light. You will not toss it around onto a bike rack mounted to your car, or pull it up with ropes onto the ceiling of the garage. That being said...I have manipulated a 5-kW hubmotor bike, and the weight was astonishing. I would rather build a...
by spinningmagnets
Oct 18 2018 4:42pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: Alta Motors Redshift
Replies: 67
Views: 2422

Re: Alta Motors Redshift

The tires, brake pads, and chains/sprockets are general purpose items, so they will remain available from a third-party seller. I am curious about what parts are "Alta-specific", and might wear out.

Buy a spare of X, Y, and Z...if you own an Alta. They appear to be pretty wonderful.
by spinningmagnets
Oct 17 2018 11:26am
Forum: Battery Technology
Topic: Lithium ion EGO 56v pack vs LiFePo4 at 30 amps
Replies: 7
Views: 258

Re: Lithium ion EGO 56v pack vs LiFePo4 at 30 amps

If the pics are on a windows computer, they can be easily resized in the program "paint".

I sometimes size them to be 700 pixels across to gill the page, and 600x400 is a good general purpose size.
by spinningmagnets
Oct 14 2018 7:40pm
Forum: EV Business World
Topic: E-bike industry spokesperson?
Replies: 36
Views: 11926

Re: E-bike industry spokesperson?

Martha Stewart on her new Pedego
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by spinningmagnets
Oct 14 2018 7:10pm
Forum: E-Bike General Discussion
Topic: Are Torque Arms for Rear-Hub Motors necessary?
Replies: 15
Views: 523

Re: Are Torque Arms for Rear-Hub Motors necessary?

I'm not sure I could explain the engineering reason a mid drive doesn't affect the drop-outs the same way. However, I have been hitting 1500W on my mid drive and the aluminum drop-outs don't have a torque-arm, and show no signs of cracks developing. Steel drop-outs are stronger than aluminum, and I ...
by spinningmagnets
Oct 13 2018 8:18pm
Forum: Battery Technology
Topic: Salvaged EV cells index: Leaf, Volt, Tesla, Zero, etc
Replies: 45
Views: 8092

Re: Salvaged EV cells index: Leaf, Volt, Tesla, Zero, etc

There is a model of Fiat that uses 5S sub-packs that are about the size of a normal 12V car starter battery. I am waiting for a response from the original poster for exact dimensions, and also the model name. 5S nominal is 3.6V X 5S = 18.0V If fully-charged to my recommended 4.1V, then 5S X 4.1V = 2...
by spinningmagnets
Oct 13 2018 4:20pm
Forum: E-Bike General Discussion
Topic: Are Torque Arms for Rear-Hub Motors necessary?
Replies: 15
Views: 523

Re: Are Torque Arms for Rear-Hub Motors necessary?

If it was a 250W rear hubmotor and a stout steel frame, I'd say it's OK. Steel would usually start to bend, and possibly give you some warning. Aluminum is more likely to develop a crack, and then suddenly snap off. You may nor fear a crash at low speed. However, besides the crash there is the repai...
by spinningmagnets
Oct 13 2018 1:32pm
Forum: Large EV General Discussion
Topic: Large ESC 500A search
Replies: 9
Views: 580

Re: Large ESC 500A search

Zero is 28S, frequently listed as 102V.
by spinningmagnets
Oct 13 2018 11:24am
Forum: Motor Technology
Topic: Motenergy ME1304 motor with SEVCON size 6 on Dyno
Replies: 47
Views: 3011

Re: Motenergy ME1304 motor with SEVCON size 6 on Dyno

Spoke to John at Motenergy, the 1304 number means it was designed in 20"13", and it is the 4th unique configuration of a product that they designed that year.
by spinningmagnets
Oct 12 2018 4:36pm
Forum: Battery Technology
Topic: DIY ajustable current source : test cell fuse wire
Replies: 18
Views: 570

Re: DIY ajustable current source : test cell fuse wire

I apologize if it sounded as if I felt a 40A "blow" spec is ideal, I really don't know what is ideal, but I do strongly feel this is a very timely subject to discuss. The 30Q cell has become very popular over the last year, and the higher-spec HG2 is rare due to a higher price, and also because it i...
by spinningmagnets
Oct 12 2018 4:04pm
Forum: General Discussion
Topic: What's the best treatment for KFF?
Replies: 60
Views: 8410

Re: What's the best treatment for KFF?

Andrew Jenkins, ES facebook
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by spinningmagnets
Oct 12 2018 4:01pm
Forum: General Discussion
Topic: What's the best treatment for KFF?
Replies: 60
Views: 8410

Re: What's the best treatment for KFF?

ES member izeman

viewtopic.php?f=1&t=96806
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by spinningmagnets
Oct 12 2018 11:12am
Forum: Motor Technology
Topic: Motenergy ME1304 motor with SEVCON size 6 on Dyno
Replies: 47
Views: 3011

Re: Motenergy ME1304 motor with SEVCON size 6 on Dyno

Speaking of Motenergy, is there a pattern to their names? 1304 = xxxx?
by spinningmagnets
Oct 11 2018 5:56pm
Forum: Battery Technology
Topic: Consequences when I don't declare batteries in shipment
Replies: 3
Views: 217

Re: Consequences when I don't declare batteries in shipment

Yeah, I wouldn't ship it as a "book" and hope it doesn't " go off". You could buy a house for the cost of the fine. Although...I hear they have a convenient payment plan...
by spinningmagnets
Oct 11 2018 11:24am
Forum: Battery Technology
Topic: DIY ajustable current source : test cell fuse wire
Replies: 18
Views: 570

Re: DIY ajustable current source : test cell fuse wire

Thanks for posting that. ES (*or somebody else) needs to become the reliable reference for DIY fuses
by spinningmagnets
Oct 11 2018 9:59am
Forum: Battery Technology
Topic: DIY ajustable current source : test cell fuse wire
Replies: 18
Views: 570

Re: DIY ajustable current source : test cell fuse wire

Bare fuse wire has a composition that is similar to lead-free solder, tin/zinc. When it blows, there will be a small amount of conductive splatter. At the lower amperages, the fuse wire is very thin, and the splatter is small. When amperages get high, the fuse-wire becomes thick, and the volume of s...
by spinningmagnets
Oct 11 2018 9:42am
Forum: Battery Technology
Topic: DIY ajustable current source : test cell fuse wire
Replies: 18
Views: 570

Re: DIY ajustable current source : test cell fuse wire

When fusing individual cells that are high current, but are assembled into a small pack...the fuse melt amperage and separation time are a critical decision. When using 10A cells in a very large pack, the acceptable performance criteria are much broader and easier to meet. An internally shorted cell...