Battery Testing - Good or bad

I have a Ring Doorbell 2 gifted from a friend.

I have fully charged the battery until only the “Green” light shown and “Red” light out. But after I plugged it in, there is no respond from the doorbell. Not sure if the device itself is bad or if the battery is bad.

The Model is Ring “Video Doorbell 2”, the battery Model is V4.

Noticed that there are 5 outlets (+ C+ D C -), using Volt-meter I measured the voltages on the battery outlets as following:

between - and +: 4.05V

between - and C+: 0V

between - and D: 0V

between - and C: 0V

between + and C+: 0.17V

What are the 5 outlets should have in voltage? is the battery no good, or is the Ring device may be broken?

Hey @hongli79. If you have a fully charged battery in like you have described it, then you should have the Doorbell boot back up. With the battery in, if the Doorbell isn’t showing any signs of life, please press and hold down the setup button for 20 seconds, and see if the Doorbell lights up then. In the event you still get no lights from the device, please give our support team a call at one of the numbers available here. We’re taking additional steps to protect our team and help reduce the spread of COVID-19. This has resulted in longer than normal wait times. If you are outside of the US, please read our response to COVID-19 here to see how to contact support.