What a great resource this site is. Anyway, I wonder if anyone can shed some light on my Xantrex C35 charge controller. I actually have three of them on three different systems on my off grid property, so I'm no stranger to them (though I'm certainly no expert). Without going into the specifics of the small system, it's been operating perfectly for years until recently--even outlasted several banks of golf cart batteries. As of several weeks, it doesn't seem to be accurately monitoring the charge nor cutting down the 12 volt input. The green light still blinks, but only one blink as if the system is not near a full charge. However the batteries are obviously being over charged--according to the ambient charge at night showing on my voltmeter and the electrolyte boiling away. The ampmeter shows the charge to be coming in even when I know they're fully charged. I've tried manually cutting off the panels and running down the batteries somewhat to no effect; when I open up the circuit again they just come back up and overcharge again. I can trigger the equalization and it blinks green/red as usual. I wonder if there's a way to reset the controller or if it's just lived out it's useful life.