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by spinningmagnets
May 31 2020 6:54am
Forum: Battery Technology
Topic: how many amps should i plan for a Diy battery and which nickel strips?
Replies: 14
Views: 409

Re: how many amps should i plan for a Diy battery and which nickel strips?

maybe 4mm wide instead of 7mm wide 0.15 nickel strips? That's fine for the parallel strips. When it comes to the parallel connections, just about any material will work, and any common thickness (0.15mm/0.20mm). I would select the material that is easiest to weld, with whatever welder you are using...
by spinningmagnets
May 30 2020 6:48am
Forum: E-Bike Non-hub Motor Drives
Topic: Ansbern ebikes thread
Replies: 10
Views: 285

Ansbern bicycles thread

This thread was split-off from the Frey Bafang Ultra thread.
by spinningmagnets
May 29 2020 10:53pm
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 251
Views: 54097

Re: Spot Welding Copper Strips to 18650 Battery Cells

A quick reminder for the casual readers, if the cost of the magnets is a concern, only the negative ends of the cells are extra sensitive to heat. Of course, if you like the magnet method, it works as well on the positive end as it does on the negative. For the positive end, I think flattening the t...
by spinningmagnets
May 28 2020 8:20pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: New builder, some quick questions for the experienced
Replies: 7
Views: 143

Re: New builder, some quick questions for the experienced

#2 E-brakes mean that when the brake lever is pulled, an embedded switch also cuts off the power to the motor so you cannot accidentally have the brakes and power on at the same time. High and low brakes "sounds like" it is for regenerative braking. This is when the motor acts as a magnetic brake. I...
by spinningmagnets
May 27 2020 2:25pm
Forum: Battery Technology
Topic: looking for the simplest balancing circuit
Replies: 42
Views: 1083

Re: looking for the simplest balancing circuit

Theres a new style of balancer I've been seeing on youtube, and I think they are called active balancers. When the bulk charge is complete to 4.1V per cell (give or take), the circuit then feeds the highest cell voltage to the lowest cell voltage. If all the cells are within 0.02V (or whatever the p...
by spinningmagnets
May 27 2020 2:15pm
Forum: Battery Technology
Topic: DIY Li-ion battery: first connect cells in series, then in parallel
Replies: 12
Views: 265

Re: DIY Li-ion battery: first connect cells in series, then in parallel

It seems obvious that it is easier to assemble a pack in paralleled groups first. However, if you are using a roll of nickel ribbon, and then stacking them on top of each other to achieve both series and parallel connections, that might add another layer of nickel for the current to pass through. If...
by spinningmagnets
May 24 2020 7:56am
Forum: Battery Technology
Topic: how many amps should i plan for a Diy battery and which nickel strips?
Replies: 14
Views: 409

Re: how many amps should i plan for a Diy battery and wich nickel strips?

Be aware that the series strips carry the current, and the parallel strips only keep the cells in that P-group equalized. This means the parallel strips carry very little current, less than 1A, even on an ebike that is using 60A peaks. Resistance in the P-strips is a good thing, it limits the cells ...
by spinningmagnets
May 23 2020 10:20pm
Forum: Battery Technology
Topic: Understanding and Using EGO Power+ Batteries
Replies: 100
Views: 30998

Re: Understanding and Using EGO Power+ Batteries

EGO is about to start selling a 10-Ah pack. Previously, the largest they made in the "56V" (14S) format is 7.5-Ah. I suspect it uses the 21700 cells, but it remains to be seen. It may not fit in the 2019 and earlier model mowers. As many of you know, the weed wacker, leaf-blower, chainsaw, etc usual...
by spinningmagnets
May 22 2020 12:58pm
Forum: E-Bike Non-hub Motor Drives
Topic: Bafang Ultra full suspension fat bike frame?
Replies: 8
Views: 411

Re: Bafang Ultra full suspension fat bike frame?

There are at least a half-dozen brands, but it seems that after the community has done some research concerning performance vs price, the Frey brand seems to be popular...
by spinningmagnets
May 21 2020 12:42pm
Forum: Battery Technology
Topic: 18650 battery contact
Replies: 3
Views: 113

Re: 18650 battery contact

There are many different discussions about this, too many to link to. All I would most like to recommend is do not use the spring as the electrical conductor. Slip a nickel, brass, or copper ribbon under the spring, so the spring is not even touching the cell. I would prefer a steel leaf spring (pos...
by spinningmagnets
May 21 2020 12:37pm
Forum: E-Bike Technical
Topic: Converting front Hub motor to a rear hub motor?
Replies: 3
Views: 152

Re: Converting front Hub motor to a rear hub motor?

If it's a geared hubmotor (which is likely) then you might consider keeping it on the front. You could add a second motor to the rear, such as a common 1000W direct drive hubmotor, and doing that would also provide the option of regen braking your make your rim brakes last longer. Can a front hubmot...
by spinningmagnets
May 21 2020 12:30pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1146
Views: 158294

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

That's impressive for an AGM. From what I have learned about the internal configuration of batteries that allows high pulse-amps, there was no reason that one like this couldn't have been made a long time ago. There only needed to be a company that thought there was a market for a physically small b...
by spinningmagnets
May 20 2020 12:07pm
Forum: E-Bike General Discussion
Topic: eZee vs MAC? Your thoughts?
Replies: 18
Views: 396

Re: eZee vs MAC? Your thoughts?

MAC hall replacement, many pics of the internals...

viewtopic.php?f=2&t=63771
by spinningmagnets
May 19 2020 8:23pm
Forum: Battery Technology
Topic: 40T, neodymium magnets, plasti dip cycle test
Replies: 88
Views: 1587

Re: 40T, neodymium magnets, plasti dip cycle test

I like pure soft copper foil as the bus contact to the cell-end. This way it can conform to the shape of the cell-end. They appear to be flat (and most are very flat), but there may be irregularities that are not obvious on every cell. A discussion about using copper contacts to allow for high amps ...
by spinningmagnets
May 18 2020 7:13am
Forum: E-Bike General Discussion
Topic: eZee vs MAC? Your thoughts?
Replies: 18
Views: 396

Re: eZee vs MAC? Your thoughts?

You can get the battery and charger from any vendor on your shortlist. If the battery-to-controller connector is different from the kit you would like to get, the plug-and-socket is easy to swap out. When it comes to the kit, get the motor, controller, and throttle from the same vendor. I also recom...
by spinningmagnets
May 17 2020 6:43am
Forum: E-Bike Non-hub Motor Drives
Topic: The "Giant Bucket of Motors" Question
Replies: 4
Views: 211

Re: The "Giant Bucket of Motors" Question

Large office copy machines have a stepper motor the size of a coffee cup. They make excellent generators. Of course they might only be able to charge your laptop or phone, but in a disaster, that might be better than nothing. Just add a bridge-rectifier, very cheap and easy to make four diodes. It c...
by spinningmagnets
May 16 2020 5:26pm
Forum: E-Bike General Discussion
Topic: Is It OK To Leave The Bike Outside In Winter?
Replies: 17
Views: 323

Re: Is It OK To Leave The Bike Outside In Winter?

I'm sure it will be fine in an unheated garage. You are right, the battery pack is the part that needs to stay warm (room temp, or more).
by spinningmagnets
May 16 2020 5:23pm
Forum: E-Bike General Discussion
Topic: eZee vs MAC? Your thoughts?
Replies: 18
Views: 396

Re: eZee vs MAC? Your thoughts?

The MAC is bigger. MAC stator is 22mm wide (135mm diameter).

eZee is 17mm wide stator (130mm diameter)

Both can benefit from ATF cooling, if you don't mind the occasional oil spot.

viewtopic.php?f=3&t=4892
by spinningmagnets
May 15 2020 10:40am
Forum: E-Bike General Discussion
Topic: Can't Get #@!!@ Tire On Rim
Replies: 48
Views: 759

Re: Can't Get #@!!@ Tire On Rim

The part where the tire bead seats on the rim, and the part where the spoke nipple seats...they are two separate and completely different measurements. Here is an image of a deep "aero" rim for a road bike: https://ars.els-cdn.com/content/image/1-s2.0-S0167610519305884-gr4.jpg I posted that to infor...
by spinningmagnets
May 13 2020 11:01am
Forum: General Discussion
Topic: Windows Gaming PC hardware, building, troubleshooting, & benchmarking
Replies: 104
Views: 1021

Re: When Windows 7 is dead in 2020 what OS will you migrate to??

What a spam fest. I will sort this out when I get off work...
by spinningmagnets
May 12 2020 11:13am
Forum: General Discussion
Topic: Hole Rivets for Two Thin Metal Plates?
Replies: 18
Views: 397

Re: Hole Rivets for Two Thin Metal Plates?

Best to not drink all 6 bottles of beer in one day
Oh no...NOW you tell me (*burp)
by spinningmagnets
May 10 2020 9:58pm
Forum: E-Bike Non-hub Motor Drives
Topic: BBSHD: I'm skeptical
Replies: 24
Views: 3387

Re: BBSHD: I'm skeptical

A while back, Luna was selling 50A ludicrous controllers, which allowed me to keep the 52V battery packs that I like very much.