I'm new to the LML and new to flying but I'm an old hat at boats (on my
16th).  We have used a 12" x 12" solar charger to keep the batteries charged
up where 120 volt power wasn't available.  Like for trailer boats in the
yard, just stick it out in the sun and walk away.  It only charges at a
trickle to keep them topped off and it won't overcharge.  That however, is
typically for marine deep cycle so the charging profile could be very
different.  But is there a reason why that wouldn't work?

Dan (still looking for a ES standard kit) Newland