I've had only one that would consistently go dead on the shelf but that was due to the decoder being bad. It was one of the cheap Lenz knockoffs from Bachmann. It finally got to where it wouldn't work at all so I changed it out with a Digitrax DZ125.
Dr. Frankendiesel aka Scott Running BearSpace Mouse for president!15 year veteran fire fighterCollector of Apple //e'sRunning Bear EnterprisesHistory Channel Club life member.beatus homo qui invenit sapientiam
i have several locos mostly athearn that i installed decoders in that i haven't run regularly. some for over a year and when i fired them up they still had their 4 digit address and speed settings. i have had some other locos drop back to factory default settings or gone dead when i picked them up and placed them back on the track reversed while cleaning their wheels but these were sound equiped. no damage there though. just a quick readdressing or reseting with the magnetic wand.
This is one of those questions the answer to which is, "it depends."
Anywhere from one to ten years, depending on which flash memory chip is in the decoder.
There is no definite answer to this question. Some lose their memory overnight and others may last forever.
If in doubt, reprogram it.
I don't remember seeing but probably did and don't remember.My question is I bought some engines off ebay and was wondering how long the engine could set and not be on the layout before the memory goes out or disappears.Hope you understand what I would like to know.Thank you for your time .
slow train Ed