Hello, I hope everyone is well and safe.   My wife bought me a phantom 3 and a spare battery a few years back, I got sick and never used it after a few months. The spare battery was never taken out of the box. I just opened the box and tried to charge it and nothing happened. I can not turn it on or check the battery level. No lights come on at all even when the charger is plugged in.  Is there any way to make it work?
Thank you for your time.

Hi Decoys

Try this link, hopefully it will help you out

https://phantompilots.com/thread ... ut-a-hammer.148222/

Fingers crossed

Hello there Decoys. I am sorry for the trouble this has caused and thank you for reaching out. Please try to leave the said battery on the charger for at least an hour to see if the said battery will take in charge. In addition I will post a link where in you can see the DJI Phantom 3 Intelligent Flight Battery Safety Guidelines ( http://dl.djicdn.com/downloads/p ... _Guidelines__en.pdf ). Thank you.

Unfortunately Decoys, LiPo's do not like being left alone and should never be allowed to fully discharge.
Have you a volt meter, can you measure the voltage across the two big terminals. If this is below about 4.5 volts, 1.5 volts/cell, it is possible that the battery is "asleep" and can be waken up with certain chargers.
Measure the voltage. Put on charge for an hour and check the voltage again. If it's going up you might be all right, continue charging. Do not leave the battery unattended while charging - put in fireproof bag if you have one but at least leave it on a non flammable surface.