Battery Tester Checker - Universal Battery Tester Monitor for AA AAA C D 9V 1.5V Button Cell Batteries - Household Battery Life Level Testers Power Meter Black B07VB4NTK8

Easy to use and accurate

I am so glad I got this! 100% worth it! I went through my 'good' battery drawer and another box full batteries I thought were dead I was planning to take to recycling. I went through the 'good' box and was surprised to find several batteries were bad. Then I went through the 'take to recycling' box and I was shocked to find about 30 batteries that were still good! The batteries were bad when I threw them in there, so how the heck did they have power again? Well I googled this question "Why do batteries come back to life?".. and found and amazing answer on howstuffworks. If you want a technical explanation google that question. Here's my short non-technical summary: There are two reasons batteries that are still good may appear to be dead: 1. If you are using several batteries in a device, only one of the batteries might go dead, but the device will stop working, when actually the other batteries are still fine. Without testing the batteries, you might assume they are all bad and throw them away. Which is part of the reason I found so many good batteries in my recycling bin! 2. The second reason is pretty technical to describe. In simple terms, basically when batteries are powering a device, due to the reaction going on, the polarities can become 'blocked' and they appear to loose power. If you let them rest for a while, the internal reaction will dissipate and the batteries will work again. In other words batteries need to rest and they can often regain their charge on their own! Of course this doesn't always work, but it often can. I have never heard of that before, but am glad I know now. This is the second reason I found so many batteries I thought were dead, were actually still good! So next time your flash light goes dead, hold on to the batteries that test as bad. Check them again in a week and you might be surprised to find some of them are good again! I figure I'm not the only person who didn't know these things and hope this is helpful to someone else. So glad I can now test my batteries and actually know if they are really good or dead instead of guessing. This thing has already paid for itself several times over in one use by all the batteries I saved! Don't hesitate! I will be getting more of these and giving them to people who will appreciate geeky but useful gifts :)

Funciona bem e evita descartar baterias e pilhas ainda com carga. Comprei o segundo para ter em casa e no escritório.

Fantastic -- almost a toy for the family - saves guessing

Atende a necessidade de teste de pilhas.