Phantom 2 v.1 - how to increase flight time?

Question

Iron

Good afternoon! It is necessary to increase the flight time of the Phantom 2 v.1 quadrocopter by lightening the weight, reducing consumption, and finished drinking various things.
Quadcopter configuration:
Boscam FPV TS832 TX 600mw
iOSD mini
zenmuse h3-3d
gopro hero 4 black
clover antenna immersion rc fat shark
Standard propellers
Software versions:
main controller ver. 3.14
Battery ver. 2.0.0.0
h3-3d imu ver. 1.0.0.12
P330CB ver. 1.0.2.10
Receiver-Phantom2 ver. 1.0.0.0
GPS ver. 6.0.1.4
Thoughts from myself:
I do not use red LEDs - I think I can turn them off? What is the best way to do this and is it worth it?
I also read about version 3.06 of the controller, that there you can still set a % limit for landing or returning home. Is it worth bothering with a downgrade?
I don’t need long-distance flights (no more than 100-150 meters) and it might be worth replacing the transmitter with a less powerful 400mw
.
Or change propellers?
Total
This is my first copter of this level - I bought it from a used one. 2 batteries 1 is swollen and flies for a maximum of 4 minutes, the second is no more than 10 minutes. What do you advise? (buying a new copter is not an option)

Answer 1

buy a battery, what is there to invent ?!

Answer 2

does it run fine on a new battery? is there any way to check this?