When i charge my phantom 2 vision battery, 1st light starts blinking then 2nd light and then its full charge with charger light turning green. I didnt see 3rd and 4th light blinking as it was in the past. Battery round button on pressing shows all four lights as solid green. Now the flight time is only 7-8 minutes, what is going on with this? Charger must be fine as battery shows 4 lights as all charged but in actual its not.

If you could, please post a screenshot of the battery status page from the Phantom/Vision Assistant.  That would be of help in getting assistance or advice.

How old is the battery?
How many charges/discharges?
Has the battery ever been dropped or involved in a hard crash?

I am reluctant to use assistant software as it requires firmware update. I am using default firmware when purchased vision back in Dec-2013. If it is really required I can do this and then check battery status. The reason I never update was what I heard it will limit phantom distance, now i can fly away from me up to 5000 ft.
Battery is 4-5 months old, purchased from flying-hobby and had very few flights, 15 with it.
The problem started after flying in dense fog one day.

abrarrafique@ho Posted at 2015-4-4 12:15
I am reluctant to use assistant software as it requires firmware update. I am using default firmware ...

check it out on assistant without live internet if worried about updates

When I open assistance software, internet is off, default tab is upgrade and a message saying "Main controller firmware mismatch, please upgrade your firmware." I cannot browse in assistance software to any other tab.