AOK Digital Battery Meter

These simple but sophisticated volt meters allow a quick check of your battery pack charge state. A quick check prevented me from putting a half charged battery in my plane. I bought several so I can pass them out to my friends. Handiest tool in my flight box.

AOK Digital Battery Meter

Cheap piece of insurance to be able to test before running a lipo battery irreversibly dead. Highly recommend these for a quick check.

very nice

Too soon to comment on reliability but this is a great example of a simple product which does the job it was designed for. No need to worry about static discharge damage either: the meter is encased in a thin, transparent soft plastic shell. In fact, I just talked myself into adding a second one to my order. :)