Batteries

From

Introduction

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:

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.

Tools

Parts

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

Soldered 18650s, 1s120p configuration @ The Fledge

v1

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

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.


Battery v3 CAD

Playground

You can try out modifications of the source code right here.


Off the shelf

Cell testing

References