I have one of those Black & Decker smart chargers, photo in the 3rd post. Glad to hear it is a good one! I bought it on a close out sale in a woodworking tool store. That night we stayed with friends who had a car with a very dead battery. I charged it and used the equalize and desulphate features. It seemed fine after that.
I find it works pretty well, though the voltage display reads several tenths high, and it does seem to quit before fully charging. Thanks for the tip about the fan! I'll keep my ears open for sounds of failure.
I have this little gem waiting in my Christmas stocking to replace the one I made in 1975 for playing around with electronics.
eBay linkI chose the ten amp version so I can manually top up batteries. No timer but I could easily plug it into an AC timer if doing something risky. It seems to work perfectly except the current meter reads two tenths low and therefore indicates zero for any current below 250 mA. It is smaller than it looks in the picture.