Project Recharge your LED Light Fixture (aka ReFIX). Many battery powered LED light fixtures are designed to run on NON-rechargable batteries. For some of these light fixtures this means one or two nights of light on a single set of batteries, then the batteries are thrown away and replaced with a new set of non-rechargeable batteries. Crazy, right?
These fixtures all use LED lighting technology due to their low energy requirements and long life. The task for you is to modify this light fixture so that it can run on rechargeable batteries, and can be charged using a solar (photovoltaic) source, thereby giving the light fixture many cycles on a single set of batteries and a daily dose of sunshine.
This light fixture is designed as a desklight and has a thermal dimmer switch to regulate brightness. The battery compartment is designed for AA sized batteries. Replacing the the AA alkaline non-rechargeable batteries with AA Nickel Metal Hydride (NiMH) is an easy swap. We’ve choosen to use a USB connector (5Volt power source) to charge the batteries. To protect the batteries from overcharging, several diodes are included to reduce the voltage seen by the batteries. The 5v USB plug can be matched with a Solar (PV) module with a 5v USB output (this is easily done using a USB Car Charger device that converts 6V-24V DC power sources down to compatible 5Volts for your light fixture.
The slides below show the modification process.
Instructions in PDF format (DRAFT)