Cheap and it filled out its use, allowing to know what my rechargeable batteries stocks still retains the energy, and to verify if a particular device does not work if the battery is empty, or if it is just a defective unit or very demanding battery. And it sometimes surprises. Two small caveats: I found battery types that we can not test it. And all my rechargeable batteries, recharged same background, are never marked as full. But I am happy with my purchase and I test every sensible battery henceforth be empty or full, and I was able to isolate defective batteries.
