I just purchased a refurbed Phantom 4 Advanced with an extra battery.  I charged both batteries up this weekend (Friday night).   I believe hte LED indications showed that the batteries charged up fully.   But....   When I tried to fly the Phantom today (Monday), one battery seemed to work for about 3-4 minutes (the LEDs on the bottom of the P4A turned on, gimbal moved around, etc), then turned off.   I then tried the other battery and both will only turn on for a few seconds---when I hold the on button for several seconds then for a short time, each battery turns on as seen on LEDs then turns off in 3-5 seconds or so.   When I try to charge them now, I see no LED indications at all on either battery.    To check that the charger is still functional, I plugged in the RC unit; it is charging fine.   What should I try next??   Thanks very much in advance.   I am ready to do my first flight!!!

NEVER MIND.   I was doing the "ON" button incorrectly--was doing long then short--got that backward.   No issue.   Batteries are both good to go.   Sorry about that folks....

'---when I hold the on button for several seconds then for a short time, each battery turns on as seen on LEDs then turns off in 3-5 seconds or so.'

You have the switch on technique around the wrong way. You press the on button very briefly, release it, then immediately press the button again and hold it until all four LEDs come on, then release it.

A warning would be in place here, even it just is a few days you should be careful in regards to the charge level.
It is recommended to charge up no earlier than a day before flight and if possible check the state before leaving by powering up the batteries and connect them to the charger, only then you can be sure it would be fully charged.

Fly carefully

Hi. Thank you for the sharing. Just a reminder to power on and to power off the Drone all you need to do is press the power button once release then press and hold the power button again for 2 to 3 seconds and release.

DJI Stephen Posted at 2018-7-3 11:41
Hi. Thank you for the sharing. Just a reminder to power on and to power off the Drone all you need to do is press the power button once release then press and hold the power button again for 2 to 3 seconds and release.

Thanks very much for all the quick replies!!   I appreciate the info

Update--Did my first flights tonight.   P4A works fabulously.   Very intuitive to fly.   Both batteries worked great.   I forgot to keep track of time, but feel like I got pretty close to an hour total from the two batts.    Will do some more flying tomorrow.   What a great viewpoint waaay up in the air.   Now gotta learn more about how to move camera around, down, etc...

Good stuff ...fly safe