ZUFECY Battery Tester Checker, Small Universal Battery Checker Tester for AA AAA C D 9V 1.5V, Button Cell Batteries Checker - Small Volt Checker for All Batteries - 4 Pack

I love these things. It's annoying when you have to change out 4 batteries, when it might be that only 1 battery is dead. I use this all the time. I keep one in my car to use at client homes (I'm a personal assistant) and have given several as gifts or ordered for clients to keep onsite.

It was only a few extra dollars to buy 4 instead of 1 so I bought 4 and gave 3 away to the neighbors. Every time a battery goes bad people throw away 4 or 5 at a time. These save you so much money because you can test each battery. Very easy to use and works well.

Great tester!! No internal battery needed to make it work.

very user friendly

I now have one for multiple locations.

Works really well.

Am giving five stars because these testers do exactly what I needed from them, which is to tell me if a given battery was good or not. No, it's not going to give you precise voltages and so on, but for me (a working musician with lots of battery powered gadgets) they're perfect. I bought the four pack (much better bargain than the dual pack) so I can keep one in every guitar case and also in my accessory bag (many guitars have a built-in preamp, and need a battery. If it fails, the instrument is dead). This tester allows me to do a quick check before going onstage, without breaking the bank if it gets broken or lost.

Works great and great value. Purchased 4 and all tested batteries equally well. Grandson likes his. Would buy again. Easy to use.