Bests & Worsts Reviews from Amazon

Edited 12/10/15 to fix some typos. Thanks for kind comments! Edited 12/12/20 as some reviewers claimed this doesn't test under load. It does! Turns out they posted to the wrong device! I also added a small information bit to help some readers better understand a few electrical terms I use. REVIEW This is a very nice analog tester. It has a quality feel, and test leads that appear likely to hold up to long use. I've bought 7 so far, 3 for me and the others as little gifts. (I dont accept payments for reviews). It handles a very wide range of batteries. I am very pleased with mine, especially at its low price. There are incredibly cheap testers available on Amazon, but they lack the ability to appropriately load the battery being tested. Here's what I mean. A battery tester works by putting a load on a battery and measuring the voltage at the battery terminals. The reason is that this voltage, measured with a good voltmeter that draws almost no current, changes little as the battery wears out. What does change is that the battery's internal resistance increases, which wastes energy, and the amount of chemicals available to generate current decreases. By putting a load on the battery, the meter can see whether the battery is still able to do its job. This tester has 9 switch positions which set it to select a reasonable load and voltage range for a battery type, giving you a much more reliable test than a plain voltmeter can. See the table below. Notice that there are 3 different current drain settings for 1.5 V batteries. These are chosen to roughly match their normal use; 1 mA for tiny button cells used for watches, 50 mA for AAA batteries, used for remote controls, and 150 mA for AA or bigger C and D batteries used for flashlights, etc. If a tester draws too much current, it can deplete the battery just by testing it, and a battery tested at too little load may test Good yet not work in your device. Understanding this, this tester is still very useful in sorting through batteries, even if your device uses an unusually high or low amount of current. Digital cameras, for example, draw a lot of current for a few seconds when they are recharging their flashes; the internal resistance of ordinary batteries wastes power, giving them short useful lives. Yet they can last for years in a low-drain steady application like a clock. So you need to use your judgement. If you find that batteries test good but only move the tester needle a little above the bottom of the green range will not work in your device, yet you might be able to use them in something else for a while. SPECIFICATIONS (from supplied manual) Range..............................Load Current.........Minimum Voltage for ......................................Drain...................GOOD Indication Button Cell 1.5V.................1 mA...................1.125V +/- 0.0W AAA-N-1.5V.......................50 mA.................1.125V +/- 0.09V AA-C-D-1.5V.....................150 mA................1.125V +/- 0.09V Lithium 3V..........................1 mA..................2.25V +/- 0.18V 6V...................................10 mA.................4.50V +/- 0.36V 9V...................................10 mA.................6.75V +/- 0.54V 12V.................................10 mA..................9.00V +/-0.72V 15V.................................10 mA..................11.25V +/- 0.90V 22.5V...............................10 mA.................16.875V +/- 1.35V Sorry about the formatting. Some Amazon doofus decided it would be nice to strip out all my tabs and extra spaces. Try landscape view if you can. On second thought, maybe I should not have called her a doofus. I am told Amazons are pretty tough ladies! Maybe they just wanted me to use up all my punctuation marks so I'd have to order a new box of periods! :-)