I bought one of those battery saver solar panels that puts out 1/4 amp in
full sunlight.  I put it in my car that was sitting outside for several
weeks without being started.  The battery was "not saved".  It was quite
near death when I went to start the car.  Is there some reverse current
leakage when the sun goes down?  Does it need to be un-plugged at night?
If so, this is a real pain.  I saw an add for a similar, but larger panel,
that had some kind of circuitry to prevent reverse flow.  I was planning on
using this for my '85 Westy, but not if I have to disconnect every night
and re-connect the next morning.
                                                        Jay