Battery life

[Rustydiver]

Now I know this subject has been flagged to death. 
But I thought I would get longer flight times my on my dji f550 hex with  4s 5000mah turnigy batteries they ar 20-30c, out in the warm today and I';m only getting 5/6 minutes did a bit off a experiment today one batter I flew like I stole it and another just went up and hovered minimal stick imput and they both lasted 5/6 minutes.
The gimbal and light are ran off a separate small battery.

So what batteries would give me longer flight times.

[Hands0n]

Hmm, its not quite as simple as that, although it isn';t rocket science either.  First we need to know a little bit about your specific configuration.

What size propellers and pitch?
What Motors (particularly KV)?
You';ve said it is a F550 so that makes it a hex
What is the weight of the hex without primary battery? (but including the secondary battery you use to power the gimbal and light)
What is the weight of the hex with primary battery (and secondary)?

I would have to think that your flight time is rather low - I fly a clone of the 550, and with a 5000mAh my flight time is nearer 13 minutes before the alarms start going off.  That is with 8045 props and 1000KV motors. 

My thoughts are that either your 550';s overall weight is the cause of the lower flight time, or prop size for the motors you are running, or even the KV of the motors!

[Rustydiver]

It';s running the standard e300 propulsion system. It';s got the self tightening 9 1/2 inch grey props.
Motors are dji 2212/920kv
In total with fight battery and secondary battery it weighs 2.7kg.
Without flight battery it is 2.2kg

Didn';t know if it was the battery';s with a low c rating draining down quick.