Since I don't spend long hours here, I decided to use 12 volts lamps. On the left is an ordinary 4WD 110 watt fog lamp. On the right is a 12 volts room lamp that came from my Toyota Hi-ace Van. The fog lamp drains the power quickly but the room lamp can survive until the next morning. I only use the big 100 volts lamp if I'm working on something small and complicated like meters and other small electronic devices. The batteries too can power up this 100 volts lamp but not for a long time so I use my engine powered generator to power it up and not the batteries.
photo taken on a cloudy day, notice the voltage reading... not bad ey!!!
Another cheap upgrade... 12 volts car CD/radio player and funky speakers. I salvaged two speakers from a Mercedes Benz and placed them inside a normal carton box, then I wrapped the box with aluminum tape for looks... It still looks ugly but it does produce quality sounds and the kids loved it.