i have a brand new phantom 2+v3.0 and have flown it already.  Flew great.  However , I only used one of the batteries, which I left at around 30% until I fly again . The other was fully charged and it'll b a total of 3 days between when I charged it and when I use it. Is this safe for the battery or too long?

Opinions would be appreciated.

No problem with the batteries.

If you're running the latest battery firmware, your batteries will auto discharge to a safe level if you leave them charged for 10+ days. That said, it's perfectly safe to keep them fully charged.

Yes, o.k as per Gerry, if you do a search in your manual you will find the new batteries are designed to dis-charge themselves if sitting for more than 10 days so they do not swell!
In any event, always good to make sure your batteries are fully charged before take off.
Note: there is als a statement in the instructions on cycling the batteries, ie. After every "x" number of charges to drain them to a certain point and then recharge,

PhantomHelp Posted at 2015-1-28 11:35
If you're running the latest battery firmware, your batteries will auto discharge to a safe level if ...

Thank you. And yes, I have tried to make sure all my firmware is up to date.  So as far as I know, it is.  

20 times i think so