Two LiPos in Parallel on a drone? Please explain how to do safely!

ArduCopter
,
1

Hey! I have 1 tattu lipo battery, the 2300mAh 45C 11.1V one, works fine, discharged 50 times more or less now, copter flies 6 - 7 minutes on it until 15% of battery capacity is left. I want to expand the flight time by getting another battery. Here is the question: should I fly one battery, then land connect the other and fly again, or make a parallel connection to the batteries and fly them both at the same time (the batteries will be exactly the same, mAh, cell count, discharge rate, etc…)

Is it safe? I WILL be charging them separately though.
Got a little scared to connect them both on my drone after reading topics like this

Also, will the discharge rate stay the same, as from one battery and only the capacity will increase, or both?

Thanks!

2

You can generally parallel batteries as you describe w/o a problem but it adds more weight than one of double the capacity. The risk is if a cell goes bad on one battery, then there can be large current flow between them. That can be trouble.

3

How can a cell go bad? By overdischarge?