Jim thanks for the tips. I bought a powerlet cable to attach to my (micro?) USB port, and it failed after about a year. It seemed to work better with a short cabled attached to a battery source. Then for FCR I did a Q&D mount job on my VFR with a cig lighter adapter plug, and plugged in a cig lighter USB socket, worked much better. I just know that port is not meant to supply power generally (my Nuvi cradle for the car uses a different plug and then has contacts for power) so when I had trouble I chalked it up to that. Sometimes I'd try bending the contacts on the GPS USB plug, but was afraid of damaging that. Kept losing power intermittenly which was driving me nuts. I also notice that the display is not as bright on that power as it is on the battery.
Oh well it was cheap and got me into the GPS era, still use it in the car when needed.