Ice storms frequently come through our area, so I wanted affordable emergency lighting in case of a power outage. I settled on a 3-watt LED light bulb, wired to a 12-volt, 8-amp-hour lead-acid battery. The light was $32 and the battery was $20. The battery will run for about 32 hours before needing to be recharged. I keep it plugged in so it’s ready to go. A good charger costs about $25.
I liked the backup lighting system so much that I bought a second battery and two more lights. In case of longer power outages, I added a 15-watt monocrystalline solar panel and a high-quality charge controller for about $100 total. The three lights completely illuminate our safe room, and the solar panel charges the battery in less than a day.
For another DIY, solar-powered lighting plan, have a look at