Over this weekend, ham radio operators (who aren't at the World Cup) are participating in an annual emergency communications preparations exercise known as Field Day (http://en.wikipedia.org/wiki/Field_day).  It emphasizes the use of emergency and alternative power sources.  In the spirit of this exercise I'm running on backup power today to determine how long my setup will last and work out the bugs.

It has not been going smoothly today, but that's the point of the exercise I suppose.

How long can your critical systems operate without grid power?