I have a electric plane and after i charged the batts I did a test run. It ran good at full for a while than it just shut off. I could go all the way off than back on but only to 3/4 power than the same thing but this time i could only go to half power. finaly it would pertty much stop all the way.Is this how it should be?? I also noticed that the batt for the motor also ran the reciver even after the motor stoped . It is not a gluider do i even need the battery pack for the receiver in the plane?? Or is this how it should be. Thanks Green thumbs

The batteries probably just ran down. The ESC will shut the motor off when that happens. Don't keep rearming it to keep flying longer (unless you get in a bad spot and you have to), that's not good for the batteries.
Most ESCs have a BEC (battery eliminator circuit) that provides power to the receiver and servos. That helps save weight; the motor battery has more than enough extra capacity to power the electronics. Don't hook up the receiver battery and the ESC at the same time (not sure what would happen but I doubt it would be good!)

What kind of plane and what kind of battery? I own a slow stick that gets a measly 2 minutes with a 270 mah battery and then the same thing happens that you described. I upgraded to a Nickel metal hydride battery that gave me 700 mah ( milli amp hours ) and increased my flight time to just under 5 minutes. A bit better. The weight of the battery remained exactly the same at 78 grams or 2.6 ounces. I am experimenting on a lithium ion battery that will give me 15 minute flight times with 2040 mah and of course very important, same weight so that the center of gravity does not change. There is a formula for figuring out how long you can fly for. You need to know the amp draw of your motor. Mine is 7.8 amps. You take the mah of your battery, for this example i will use my first battery which is 270. Put a decimal point in front of the mah .270, times that by 60, and then divide by the motor amp draw, 7.8. This will give you an answer of 2.0 and than a whole bunch of numbers that you dont have to worry about.
My other battery:

.700 x 60 = 42

42 divided by 7.8 = 5.3

And there you go, Good luck, I hope I didn't confuse you more, try this site Balsapr.com Good battery info.

I use a GWS 6cell, 400 mAh battery in my Slow Stick and it will run at full power (static) for 7 minutes if properly charged. In the air it's good for about 10 minutes or more at about 1/2 throttle. Wasn't too good at first until I switched to a Hitec charger that peaked the battery fully.

the batts are 500 mah 6 cell I checked your formula and I come up with 4 min. Dose the prop make a diff? I had a 9/6 untill my second test when it took off into the table leg and broke it! I whent and bought a 9/4 thats all they had I havent tested yet but the waight is 5 grams more. Is the pitch diff enought to off set the weight?? also I have a 8 cell 500 mah dose that work in the formula?? Pertty sure motor is 8 amp draw thanks alot this really helps

Don't try to fly with the 9x4! It probably won't have enough power.
The 8 cell battery won't last as long because the motor will draw more current. This may wear out the motor faster.

just checked it out got exatly 4 min
. 8min plus at half. The 8 cell ran the same time but seemed stronger I guess mah is mah

As much as I would love to take the credit for that formula, I can not. I read it in an awesome book by Bob Aberle. There is a ton of more info that will be sure to help you out, it certainly helped me.

http://www.rcstore.com/rs/general/de...2028&catego=BO[/L]

I don't think that link worked, here it is again


http://www.rcstore.com/rs/general/de...2028&catego=BO

thanks for the info. theres really alot to put togeather a good combo for flying. Live and learn