I bought my husband the Phantom 3 as his final wish for Christmas in 2015. He passed in March 2016 and he never got to even use the drone.

It has been sitting my house, boxed up, ever since. My son decided to use it, but cannot get the battery to come out of hibernation mode.

2 questions:

1-Can I just purchase a replacement battery?

2-Is it even worth it or is the thing trash? It's brand new. My husband only opened the box, it never had any flight time, but it has been sitting. I'm prepared that it may just be a lost cause.

After 5 years, it's going to be a lost cause.   

Yes ....you can buy replacement batteries.
The battery in the controller might also be a problem.

Labroides Posted at 4-20 14:58
After 5 years, it's going to be a lost cause.   

Yes ....you can buy replacement batteries.

The controller seems to be charging just fine?

Hi there. Thank you for reaching out and we're deeply sorry for the trouble that this has caused. Can you please try to leave the said battery on the charger for approximately 2-3 hours and check if the issue still persists? You may try to access the link below for you to possibly purchase another battery for your Phantom 3. Please keep us posted. Thank you.

https://www.dji.com/where-to-buy/

DJI Paladin Posted at 4-20 17:11
Hi there. Thank you for reaching out and we're deeply sorry for the trouble that this has caused. Can you please try to leave the said battery on the charger for approximately 2-3 hours and check if the issue still persists? You may try to access the link below for you to possibly purchase another battery for your Phantom 3. Please keep us posted. Thank you.

https://www.dji.com/where-to-buy/

Yes, after leaving it on the charger for 4 hours, there is still no response from the battery.

jjmears Posted at 4-21 20:59
Yes, after leaving it on the charger for 4 hours, there is still no response from the battery.

Thank you for keeping us posted. In this case, we suggest you to purchase a new battery for you to use your unit. Thank you for your understanding and support.

DJI Paladin Posted at 4-26 04:03
Thank you for keeping us posted. In this case, we suggest you to purchase a new battery for you to use your unit. Thank you for your understanding and support.

Where can I purchase an authentic Phantom 3 Std battery? I am in the US.

These appear to be authentic.  If not, you can return them.

https://www.ebay.com/itm/1252604 ... :g:Ws0AAOSwv5liEaNZ

https://www.amazon.com/Original- ... %2Caps%2C65&sr=8-13

The Amazon return might be complicated since it's coming from China - it's against US postal regs to ship a lithium battery overseas.

You can also buy a used battery.  Ask the right questions before your purchase.  

OEM 15.2V 4480mAh DJI Phantom 3 Intelligent Flight Battery - Tested & Free-Ship | eBay

Good luck

jjmears Posted at 5-21 14:30
Where can I purchase an authentic Phantom 3 Std battery? I am in the US.

Hi there. Thank you for reaching out. Unfortunately, we don't have this available on our store website. You may want to check the link below for you to possibly purchase the said battery. Thank you for your valued support.

https://www.dji.com/where-to-buy/retail-stores

This video shows how to remove the PF flag with free software and a $5 2ic board
https://www.youtube.com/watch?v=_hqVS_H2Q8U