Posted for "George Shattuck" <kloop@plantationcable.net>:

 I installed a Concorde RG-35A in November, 1999.  It is still in there lo
these many years and about 640 flight hours.  But, I had changed out the same
battery two times over three years previous.  In 1999 I started putting a
trickle charger (about $30.00 item) on it when the airplane sat for several
days, especially in the winter.  Seems to do the job.
 
 George Shattuck
 N320GS, LNC2