Meloman, it sounds if you are new to Lipo batteries.
Real quick on some items that are a must to remember.
Lipo cells are 3.6v per cell, max voltage per cell is 4.2v and minimum voltage is 3.0v per cell.
DONOT forget this info. A good Lipo charger will hold you batteries to these limits when charging and a good Lipo Speed Control will shutoff at the lower voltage. Be sure it is set for the correct number of cells in the battery pack you are using. Trying to manage this your self is to difficult and risky.
If you get outside of these voltages it could result in a fire. The fire is like a flare, once it starts it will not stop until it is used up. And if one cell starts it will usually inginte another cell until all the cells are used up. The cells will usually show signs by swelling before a fire starts but in a plane at 200ft I don't think you will notice the battery swelling. You will notice the fire and if it is a war bird please get video of it. It may look realstic.
The newest Lipo cells are very good about being chemically structured to resist a fire but it cn happen.
Do not chage your batteries unattended and do it on concrete if possible.
Lipo's are great batteries, I will never go back to NiCads or others but they have limits to stay within.
Good Luck and have Fun ! ! !