Batteries

Challenges

Solar PV panels are inexpensive and durable. As are the power conditioning electronics. Batteries, however, are expensive, prone to failure, and often discarded as trash. Can we reduce trash output while solving our expensive battery problem?

Approaches

Recycle batteries from the trash stream to build new, high capacity, long lasting battery packs.

Battery (Recycled 18650 lipo cells)

Rationale:

Single battery system from tools -> teslas. I'll be bringing these tools in with me, to work with:

• https://www.amazon.com/Weller-WES51-Analog-Soldering-Station/dp/B000BRC2XU/
• https://www.amazon.com/CHEERSON-Original-Version-Discharger-Temperature/dp/B00ZGZZ40K/
• https://www.amazon.com/uxcell-Black-Pointed-Batteries-Holder/dp/B00FGX8NVO/
• https://www.amazon.com/Tzou-Charger-18650-Rechargeable-Battery/dp/B005DCOQ8W/

And here's what I've purchased to build my battery - note they're all available with prime shipping, except for the BMS, which probably won't arrive in time for the first build day. The battery I'm building is 48v, or 13S (13 cells in Series). For other voltages, you might find a BMS available with faster shipping.

• https://www.amazon.com/Farmunion-Battery-Radiating-Plastic-Bracket/dp/B01HQB085C/
• https://www.amazon.com/orlov-Solder-14500-Rechargeable-Battery/dp/B01L89QEIS/
• https://www.amazon.com/LHI-Female-Bullet-Connectors-Battery/dp/B00XBLLG5S/
• https://www.amazon.com/Li-ion-Lithium-Battery-Protection-Balance/dp/B01M1M984L/

Parts

• https://www.amazon.com/gp/product/B00ND7J38C/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1
• https://www.amazon.com/gp/product/B00FGX8NVO/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
• https://www.amazon.com/gp/product/B00S7G4A14/ref=oh_aui_detailpage_o00_s01?ie=UTF8&psc=1

Development targets

Battery charging for the universal controller Brass / Steel Battery - ​ http://pubs.acs.org/doi/ipdf/10.1021/acsenergylett.6b00295

• Coroplast box cell container
• Frame / caster racking system
• Charge controller?

Printed 18650 battery container block - spring-loaded (printed springs?) contacts + locking door. Serviceable fuses and diodes

Development History

v0

• 

  Battery v0

• 

  Battery v0

Soldered 18650s, 1s120p configuration @ The Fledge

v1

• 

  Battery management system

• 

  Battery assembly

• 

  Battery v1

• 

  Battery v1

Soldered 18650s, 7s20p configuration w/ 20A BMS.

v2

• 

  Battery v2 Assembly

• 

  Battery v2

• 

  Battery v2

Based on 18650 NESE Modules. 7s7p configuration w/ 20A BMS x2, MPPT-7201A solar charge controller and DC-DC buck-boost converter, 500W motor controller, modular frame + quick disconnect pins.

v3

Purpose modeled replimat printed part w/ printed springs, zinc plated steel 5x1 plates as electrodes, lock-nutted electrode studs, USB power, 20p5s.

• 925W BMS
• 6-32v USB QC3 converter
• MakerFocus 5pcs Mini Digital Voltmeter DC 0.28 Inch Three-Line DC 0-100V Mini Digital Voltmeter Gauge Tester LED Display Reverse Polarity Protection and Accurate Pressure Measurement 5 Colours

Battery v3 CAD

Playground

You can try out modifications of the source code right here. // Here we define the user editable parameters: function getParameterDefinitions() { return [ { type: 'float', name: 'nozzle_width', caption: 'Nozzle width', default: 0.4 }, { type: 'float', name: 'walls', caption: 'Walls', default: 2 }, ]; } function shell(params){ return CSG.cylinder({ start: [0, 0, 0], end: [0, 0, 65], radius: (19+wall_thickness*2)/2, resolution: params.cylresolution }); } function batteryyyyyyy(params){ return CSG.cylinder({ start: [0, 0, -1], end: [0, 0, 66], radius: 19/2, resolution: params.cylresolution }); } function battery() { var cube = CSG.cube({ center: [beam_width/2, beam_width/2, (length*beam_width)/2], radius: [beam_width/2, beam_width/2, (length*beam_width)/2] }); var holes = []; for (var i = 0; i < length; i++) { holes.push(xHole(i)); holes.push(yHole(i)); } var beam = cube.subtract(holes); beam.properties.myConnector = new CSG.Connector([10, 0, 0], [1, 0, 0], [0, 0, 1]); return beam; } function zBeam(length) { var cube = CSG.cube({ center: [beam_width/2, beam_width/2, (length*beam_width)/2], radius: [beam_width/2, beam_width/2, (length*beam_width)/2] }); var holes = []; for (var i = 0; i < length; i++) { holes.push(xHole(i)); holes.push(yHole(i)); } var beam = cube.subtract(holes); beam.properties.myConnector = new CSG.Connector([10, 0, 0], [1, 0, 0], [0, 0, 1]); return beam; } function main(params) { params.cylresolution=(params.quality == "1")? 64:16; var nozzle_width=params.nozzle_width; var walls=params.walls; var wall_thickness=nozzle_width*walls*2; //for (var j = 0; j < 4; j++){ //return CSG.cylinder({r: 19/2, h: 69}).rotateX(90); return CSG.cylinder({r: 9.5, h: 65}).rotateX(90); }

Off the shelf

• LiFePo4 battery deals

Cell testing

• Opus BT-C3100
• Tenergy 5-in-1 Intelligent Battery Cell Meter
• https://megacellcharger.com/
• LTC®6804 3rd generation multicell battery stack monitor
• Attiny84 has 8x 10bit ADC, 640, 1280, 2560 have 16x 10bit ADC

References

• https://www.electricbike.com/diy-battery-pack-kits-four-options-2017/
• http://rc-monster.com/forum/showthread.php?t=28834
• OSE Open Source Battery Pack
• Arduino BMS Shield, more detail
• JLCPCB
• https://github.com/stuartpittaway/diyBMS
• https://github.com/chickey/diyBMS
• http://hmsemi.com/downfile/DW01A.PDF
• https://datasheet.lcsc.com/szlcsc/HYCON-Tech-HY2213-BB3A_C113632.pdf
• DIY or Buy
• Power tool battery adapter