The 12-volt battery provided DC to my inverter causing its cooling fan to hum nicely as it converted DC to AC for the DVD player running a recent movie. Watching the player operate, I began to wonder how long my charged battery would continue providing power like this. Soon I was deep in research on battery run times and visited a number of fascinating and interesting websites. Along the way I found Peukert’s Law, Ragone and the reality of battery backup.
With my creative and inquisitive juices active and eager, I shut down the system and replaced the 12 volt 35Ah battery with two 6-volt 3.5Ah batteries connected in series to supply 12Vdc. Then I energized the 400W inverter and smiled as its internal fan immediately started up. Plugging in the portable DVD player into one of the inverter’s AC output sockets I was pleased to see the DVD player energize and begin playing a test sample DVD movie.
Then I sat back and monitored the operation of (continue reading)