Bests & Worsts Reviews from Amazon

I bought both the Amprobe BAT-200 and D-Fantix BT-168D. If I had to buy only one, it'd be the Amprobe. I'd also recommend it if you're not the sort of person who eats Volts and Amps for breakfast. But each has its virtues. Details follow: The two testers are nearly identical physically, but the Amprobe has a more solid feel to it. The Amprobe uses an analog meter movement, whereas the D-Fantix is digital. There is a helpful table on the back of each meter that gives advice on when to replace a battery. The key functional difference is that the Amprobe meter places a simulated load on the battery when testing it, whereas the D-Fantix does not. I believe a modest load is a good idea when testing most batteries because it's more realistic for most applications. It's this idea of loading that explains why some reviewers are bound to be unhappy with any battery tester. A battery you've taken out of a flashlight as dead might still run a wall clock for months. That's because the job of powering the flashlight is more like a sprint and powering the wall clock is more like a marathon. Not a perfect analogy, but the point is that you'll find reviewers of battery testers who say that the tester is defective because it said a battery was no good even when it would still run their clock just fine for months. Or they'll say that a tester is defective because it said a battery was fine, yet it wouldn't run their flashlight. The point here is that with any tester, there will be a questionable zone where your battery may do fine in some uses yet completely fail in others. A tester like the Amprobe that places a simulated load on the battery is more likely to say that a battery is no good when it'll run your clock just fine. A tester with no load like the D-Fantix is more likely to say that a battery is good, even when it won't run your flashlight. So the right way to use all testers is to check them with batteries that have just died. When the clock stops, test the battery and note what it reads. Same for your flashlight. That'll tell you how to mentally adjust the tester's reading for the particular devices where you use your batteries. Which leads to one final comment on button batteries, watch batteries, coin cells, etc. You can just tell by how little they weigh compared a big honking D cell that they don't have a much oomph. The Amprobe meter has an appropriate load for 9 V batteries and for 1.5 V batteries down to AAA. But I found that the load was too strenuous for the smallest of the button batteries, especially when they were used in low-demand applications like watches or heart-rate monitors. If you'll be testing a lot of these smaller batteries, you may be better off with the D-Fantix.