Maybe someone here can clarify the specs of batteries. Start with mAh, does that give my batteries more capacity allowing me for longer flights? For example, say I have two batteries, both 11.1v lipos but one is 800mAh, the other is 1300mAh. What do I gain here if I have more mAh? If it is longer flight time, I am wondering since my F18 and mirage 2000 both have an 11.1v 1300mAh if I could get a 2200mAh and get longer flight time provided the battery fits in the compartment? Then what about a 15C or 20C, I don't have any idea what this spec describes. Last, I could be wrong but I think the higher the voltage, the more power the plane will have, giving it more acceleration and climb limiting you to the motor and esc limits? I know this is how it works with my 9.6v vs the 8.4v in my super cub so I imagine this is the same with the lipos.

aircrafking you are correct about the ma, the higher the ma the longer flight you will get, as a rule of thumb, now the C rating is a discharge rating. Lipos have to be kept within their calculated C rating of discharge or they will get hot and puff up or even fail and possibly catch on fire. The higher the C rating the higher the amp draw it can handle
Now the only thing you have to watch with increasing your ma is size and weight, because of course as you go up so do they.
Yes just like nimh or nicd the higher the V the more performance from the motor, but you have to know what V your motor can handle
I would suggest you look into a watt meter, this is a very handy tool, you hook it between your ESC and batt to tell you what amps your pulling and how many watts your producing. Take it from someone that has lost lipo's because of not having one, it's worth the 50.00. It can save hundreds in damaged lipo's due to over amping them in flight
I hope this helped

Thanks alot AJ, extremely helpful! I will check into a watt meter sounds like it would be more then worth it.

The "C" rating helps you determine the maximum current a battery can provide. Multiply the capacity in Ah (amp-hours) times the "C" rating to get the maximum current.

Example 1: 800 mAh battery rated at 15C.
800 mAh = 0.8 Ah.
0.8 x 15 = 12A. So this battery can provide a maximum of 12A.

Example 2: 1300 mAh battery rated at 20C.
1300 mAh = 1.3 Ah.
1.3 x 20 = 26A. So this battery can provide a maximum of 26A.

Now the bad news. Some battery makers are extremely optimistic with their "C" ratings. So you can't always get the amount of current shown by the calculations. It's always wise to discount the "C" rating somewhat to give yourself a safety margin.

What happens if you try to draw more current than the battery can provide? The battery may overheat and be damaged. With lipos, this can result in permanent damage, and the battery can become a safety hazard.

AJ's suggestion to get a wattmeter is a good one. It is the only way to know for sure what's happening with an electric flight power system.

- Jeff

Even more help Anyway, I ran into a problem. AJ mentions how a lipo can puff up and I am experiencing this. The very battery that came with my F-18 is doing this same thing. It is puffing up and does so more and more after each flight and charge and I am afraid this thing is about to blow up. I am not sure why it is doing this, I never modified anything in this plane and its all original. I notice the battery is listed as 18C but on the site it says the F-18 has an esc that is a 20amp which makes me wonder if this is the problem? If so I need to contact hobby lobby and see if they can send out another battery. I will not dare attempt to use this battery I got again.

Puffing may occur if you over-discharge a lipo or discharge it at too high a rate. The current rating of the ESC has nothing to do with it.

You might have flown too long and allowed the battery voltage to drop too low, or perhaps the battery can't safely provide the current that your power system is drawing.

Whatever the cause, a puffed lipo is a damaged lipo. You are correct to be worried about it. My advice is to slowly discharge it completely and dispose of it.

- Jeff

DISCARD this puffed Lipo before it starts a fire and causes major damage. Some likely reasons for this are most likely one or more of the following: discharging below 9v cutoff; overheating battery; not balance charging; not allowing a cool down rest period before recharging; defective motor drawing too many amps; defective battery.

Are you using a lipo charger with built-in balancer and charging via the smaller 4-pin connector. Don't charge through the larger discharge connector unless you have a Blinky Balancer connected to the 4-pin connector. With your lipo you could balance charge as high as 1.3 amps (1300mAh = 1.3amps).

An 18C 1300mAh lipo should be able to handle a continuous discharge of 23.4 amps (1.3 x 18 = 23.4) and short 5 second bursts as high as 35amps without excessively overheating the lipo. As mentioned previously this may be too highly rated by the manufacture, so 20 amps continuous discharge with 5 second bursts at 30amps followed by at least 30 seconds below 20 amps) is more realistic.

I have a 20oz plane with a brushed 480 motor that draws 14amps at full throttle during takeoff/climb with a fully charged 11.1v lipo. Normally, when cruising the motor draws only 4 amps at half throttle. I use a 2000mAh 8C lipo with a continuous discharge rating of 16 amps with 24 amp bursts. This 8C battery doesn't even get warm as the pilot and plane prefer a more conservative flying pattern once airborne. So, a $25 - 11.1v 2000mAh 8C lipo offers plenty of capacity in this plane - provides at least 12 minutes of enjoyable flying.

This 8C Lipo would be an accident(overheating) waiting to happen and a much shorter flying time in any 20oz sport/racing plane powered by a brushless motor drawing 20amps with a pilot that prefers full throttle most of the time. But when powering a brushed 480 motor--its the motor that overheats and eventually gets fried, while the battery barely gets warmer than your hand with a moderate flying pattern..

I appreciate all the advice, you guys have been extremely helpful. As of now, neither one of my Lipos work anymore. I had two of them that came with my planes, one for my Mirage 2000 and the other for the F-18, both batteries are shot. Although the Mirage battery is not puffed up, it only gives my plane just under a 2 minute flight on a full charge before shutting off and forcing me into an emergency landing. It appears from coming to an overall conclusion about what you all have said, I think I may have ran the batteries down too much. I did have the F-18 at full throttle for a while, lucky if I got a 4 minute flight before the battery died and forced me into an engineless approach. So let me see if I understand another thing correctly, never let a Lipo battery drain to the point that your aircraft motor shuts off? I maybe simply be flying the planes too long if this last question is correct. The F-18, well I guess with that one I think I got too carried away at full throttle and pushed the plane to its limits possibly overheating the battery up too much and letting it die for the 3rd time which may caused it to fry. I am going to pickup a couple of 2000mah lipo batteries that have a little higher C rating and I think those will be alot better.