VoltVault

A DIY solar-charged portable power station built from recycled laptop batteries, housed inside a toolbox, complete with inverter, BMS, cooling system, and solar controller.

Overview

VoltVault is a portable power station I built in 2021 as my final high-school project (Gymnasiearbete). The idea was to create a fully functional solar-powered energy unit using reclaimed 18650 lithium-ion cells from old laptops that were going to be recycled.

Story & Background

The idea came after noticing one of my teachers collecting old laptops destined for recycling. As a tech enthusiast, I saw an opportunity — laptop battery packs contain high-quality 18650 cells that can be reused. After explaining my project idea, my teacher allowed me to take the battery packs.

I carefully opened the packs, removed the cells, charged them, and tested them over a week. Any cell whose voltage dropped below a certain threshold was discarded. After testing everything, I ended up with over 120 good cells.

Technical Build

I assembled the cells into a large custom battery pack and connected them to a Battery Management System (BMS) for safe charging and discharging. Everything was mounted inside a sturdy toolbox, making the entire system portable and rugged.

  • Battery Pack: 18650 cells from recycled laptops
  • BMS: For cell balancing & protection
  • Inverter: Converts DC → AC for normal outlets
  • Solar Charge Controller: Enables solar panel input
  • Cooling System: Two PC fans with temperature-activated circuit
  • Safety Switch: Master cutoff switch
  • Display: Shows voltage, temperature, status

Real-World Use

I mainly use VoltVault during the summer when I'm out with friends, to charge phones, speakers, or small devices. In the end, it's essentially a portable outlet — but one built entirely by me, powered by recycled batteries and solar energy.

Photos

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What I Learned

This project taught me about solar power systems, lithium-ion battery safety, electronics cooling, energy storage, and designing practical DIY hardware solutions.