You may have noticed that your home runs on either 120V or 240V instead of the 12, 24, or 48 volts a battery supplies. Off-grid homes, small holiday cottages, boats and recreational vehicles used to use 12V direct current systems but such low voltages (and DC) are only useful in very small installations. There are relatively few low-voltage appliances and wiring a low-voltage direct current system is often difficult and unviable for a typical home in full-time occupation. 

Many people still believe that we are naturally entitled to cheap energy, regardless of increasing gasoline costs or the high subsidies for the rising cost of imported heating oil. Every gallon of gasoline offsets the cost of American military guarding the Middle East, trickling subsidies, cheap government land with heavy investment in drilling and developments in exploration technologies. But these costs do not include the damage to health or the environment that come from fossil fuel consumption.  

A lot more people are choosing self-employment from a home office after the last round of unfavorable corporate downsizing. A home office (or telecommuting) refers to working at home using computers and other related appliances; the office often doubles as entertainment thanks to the equipment’s flexibility to play games, socialize online and so on.

A typical flashlight holds two or three cells (batteries). When these cells are placed in series or a stack, the voltage increases. For instance, a 1.5V battery flashlight: when two cells are placed in series, the voltage increases to 3V (1.5V + 1.5V).