One of the projects with which I have been tasked needs to run on solar power. The average power draw would be negligible. However, it would infrequently see brief periods (1-5 seconds) of high-current draw, between 1-4 amps.
The first thing that popped into my mind was 4 AA nicads, hooked (with a diode) to a panel which would provide about 1/30th to 1/50th of the "C" rating of the battery - just enough to make up for the brief power bursts and self-discharge, and not enough to damage the battery.
Now, my question: Will trickle-charging on that sort of level - day in, day out - degrade the batteries noticeably over the normal degredation from time and cycling? A battery replacement schedule of once per year would be acceptable - but that should be a preventative measure, not due to failure.
If that is, indeed, sufficiently kind to the cells, then I will jump with it and run due to low cost and component count. But if not, then I guess I'll have to add some charge-control circuitry.