Sirs,

 

We purchased an SB3048 last year from Direct Power in Albuquerque for use with custom PV panels on high altitude balloons.  We have thoroughly tested the unit at 120k ft. altitude pressures and from -40 to +60 degrees C.  We have subjected the input to over 110 volts input, which our panels could output during the -90 degree temperatures encountered during ascent.  The unit performed flawlessly.  We have been using AGM type sealed lead acid batteries for the application where the payload is in the sun continually for several weeks while flying over Antarctica and are preparing for a test flight.