DIY lithium powerbanks

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5chn3ll
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DIY lithium powerbanks

Post by 5chn3ll » Mon Jan 14, 2019 8:15 am

My journey down the LIPO rabbit hole continues.

This is a 2-cell version of the single 18650 "power rod" powerbanks sold in vending machines in airports everywhere. In this case, the two cells are wired in parallel so if one cell dies, the bank will still work. Since I'm giving these to family, I'm only using top-shelf old-stock new cells that I test beforehand (old-stock new cells are harvested from laptop batteries that never get sold - eventually, that stock has to be liquidated or recycled). The circuit board limits total current to 3.1 amps; it also steps up the voltage from the ~3.6 volt range produced by the 18650 and handles (via the micro USB port between the two USB charging ports) recharging the cells.

Materials costs:
Controller circuit board: $4
Samsung/LG/other "premium" reclaimed 18650 cells: $2
Miscellaneous (3D printer filament, screws, flux, solder, wire, wire connectors): $1

I'm never going to save my way to wealth and fame by making these myself, but the few I've given away have been very well received - it seems like the combination of "handmade" and "reasonably useful" works.
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Understeer: You will hit the wall with the front end.
Oversteer: You will hit the wall with the rear end.
Horsepower: How hard you will hit the wall.
Torque: How far you will move the wall.

Gone hunting with Alec Baldwin and Dick Cheney. Back soon.

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5chn3ll
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Joined: Fri Jan 05, 2018 4:35 pm

Re: DIY lithium powerbanks

Post by 5chn3ll » Mon Jan 14, 2019 8:17 am

Another photo of the finished gadget...
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Understeer: You will hit the wall with the front end.
Oversteer: You will hit the wall with the rear end.
Horsepower: How hard you will hit the wall.
Torque: How far you will move the wall.

Gone hunting with Alec Baldwin and Dick Cheney. Back soon.

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FRUNKenstein
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Re: DIY lithium powerbanks

Post by FRUNKenstein » Mon Jan 14, 2019 8:42 am

I would like one mounted in one of gnat's Power Ranger heads, please.

(for free, of course)

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www.kansascityautomuseum.com
Current:
2002 996TT X50, Guards Red
1987 928S4, Guards Red
1987 951, Guards Red
1973 914 2.0 Bahia Red

2006 955S, Lapis Blue
Other toys:
1988 BMW 325i Cabriolet, Alpin Weiss
1987 Bertone X1/9, Verde Chiaro
Gone but not forgotten: 1975 914 2.0, Laguna Blue; 1999 996 C4 Aerokit Black; 1990 964 C2 Guards Red; 2006 955S Arctic Silver

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5chn3ll
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Joined: Fri Jan 05, 2018 4:35 pm

Re: DIY lithium powerbanks

Post by 5chn3ll » Thu Jan 31, 2019 10:22 am

Some additional 3d-printed 18650 battery holders. The three-cell pack is wired in parallel; the four-cell pack is set up to use three cells in series (for 12ish volts).
20190131_102137.jpg

Understeer: You will hit the wall with the front end.
Oversteer: You will hit the wall with the rear end.
Horsepower: How hard you will hit the wall.
Torque: How far you will move the wall.

Gone hunting with Alec Baldwin and Dick Cheney. Back soon.

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32wildbilly
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Re: DIY lithium powerbanks

Post by 32wildbilly » Thu Jan 31, 2019 5:59 pm

5chn3ll wrote: Thu Jan 31, 2019 10:22 am Some additional 3d-printed 18650 battery holders. The three-cell pack is wired in parallel; the four-cell pack is set up to use three cells in series (for 12ish volts).

20190131_102137.jpg
1yk1ez.jpg
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Never gonna make you cry...

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5chn3ll
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Re: DIY lithium powerbanks

Post by 5chn3ll » Fri Feb 01, 2019 8:55 am

That looks more like electronic squalor. Looks like he's building retro game units (or emulator cases for raspberry pi or Arduino, maybe). I see a 4x16 character LCD I could use, but that junk is a bit too solid state for my tastes.

Understeer: You will hit the wall with the front end.
Oversteer: You will hit the wall with the rear end.
Horsepower: How hard you will hit the wall.
Torque: How far you will move the wall.

Gone hunting with Alec Baldwin and Dick Cheney. Back soon.

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32wildbilly
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Re: DIY lithium powerbanks

Post by 32wildbilly » Fri Feb 01, 2019 9:26 am

5chn3ll wrote: Fri Feb 01, 2019 8:55 am That looks more like electronic squalor. Looks like he's building retro game units (or emulator cases for raspberry pi or Arduino, maybe). I see a 4x16 character LCD I could use, but that junk is a bit too solid state for my tastes.
You really are this guy...aren't you!?
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Never gonna make you cry...

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5chn3ll
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Re: DIY lithium powerbanks

Post by 5chn3ll » Fri Feb 01, 2019 9:46 am

More like this guy:

Image

Although this guy is pretty damn awesome:

Image

Understeer: You will hit the wall with the front end.
Oversteer: You will hit the wall with the rear end.
Horsepower: How hard you will hit the wall.
Torque: How far you will move the wall.

Gone hunting with Alec Baldwin and Dick Cheney. Back soon.

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32wildbilly
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Posts: 5758
Joined: Sat Jan 06, 2018 2:46 pm
Location: Kneebraska

Re: DIY lithium powerbanks

Post by 32wildbilly » Fri Feb 01, 2019 11:17 am

5chn3ll wrote: Fri Feb 01, 2019 9:46 am More like this guy:

Image

Although this guy is pretty damn awesome:

Image
Speaking of the Darwin Awards...those are a couple of prospective future candidates!
Never gonna make you cry...

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5chn3ll
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Posts: 4640
Joined: Fri Jan 05, 2018 4:35 pm

Re: DIY lithium powerbanks

Post by 5chn3ll » Fri Feb 01, 2019 11:30 am

The first guy, definitely. The second guy is Jörg Sprave, the German madman who runs The Slingshot Channel on Youtube.

Here's one of my favorite Jörg creations: a circular-saw-blade-shooting "trebuchet:"

Image

Understeer: You will hit the wall with the front end.
Oversteer: You will hit the wall with the rear end.
Horsepower: How hard you will hit the wall.
Torque: How far you will move the wall.

Gone hunting with Alec Baldwin and Dick Cheney. Back soon.

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