Swore off the Harbor Freight tenders too. The indicator light lights up when you hook them to the battery, so you can't tell if they are charging or not. On mine the connection from the wall wart went bad going into the box with the indicator light, so no charging, but the light stayed lit. Cost me a battery.
Menard's have a variety of tenders for around $20.00. I have a couple of those, and so far they've been reliable. As I mentioned elsewhere, unless the vehicle has a known drain while shut off, I don't tend to keep my batteries on tenders. Just hook them up once a month (during the winter). And be sure they are fully charged before the first start in the spring.
I don't have any complaints about the cheap multimeters, though. Have 3 or 4 of them around the house and garage. I doubt they are perfectly accurate, but they are good enough. On the 20V DC scale, they're usually within a tenth or two of each other. Cheap enough that I have no fears loaning them to people, in fact usually I tell them not to bring them back. I just pick up a new one. I've had better luck with them than with the $25.00 Radio Shack meters they replaced.Can usually get the HF meters for $5 or less on sale.