not sure what you mean by the "amperage issues"?
I believe capacitors or better yet, super-caps would provide sufficient current for a second or so in a minimum of space. (i.e. better energy density). They also require some circuitry which is a diode and resistor.
while batteries could be used, I believe they would occupy more space and require an additional charging circuit.
I don't believe watch batteries can provide sufficient currrent and you would need several (8) to provide 12V and watch batteries are not rechargable.
greg - Philadelphia & Reading / Reading
ndbprr:
As Greg suggests, watch batteries have some limitations. Lithium batteries would work but I question why a manufacturer would spend the time designing a battery powered keep alive system when they could invest those resources designing dead rail systems instead. Perhaps, once dead rail has been sorted out, the technology could be used to design a keep alive but if I was a manufacturer I would be spending my money on dead rail first.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!