Originally Posted by
grampi50
I haven't bought any flight batteries yet. What size would I need if I use one of the IBECs?
Size depends on your airplane size, the servos, how many flights you expect between charging and your flying style. Will you be using redundant batteries or a single battery? 30 and under planes, I usually use a single battery and several 50 size planes I have use single batteries. Above that, dual batteries are the norm for most people. The beauty of modern batteries and chargers is the charger will tell you how much capacity you take out of the battery during use and how much the charger puts back into the battery to charge it. There is a weight penalty going to larger or more batteries but cost doesn't increase drastically with larger sizes. I prefer A123 LiFe batteries usually in the 2500 MaH size. These are a hard can type battery very similar to the Nixx batteries that were so common in the past. The pouch style batteries are also very common and available in a wide variety of sizes. I use several of these in the 2800 - 3500 MaH size range. All of these newer batteries are extremely reliable, I would venture to say much more reliable than Nixx ever were. LiFe batteries are also very safe in use and when charging. Regardless of which battery style you choose, the ignition will use very little power per flight. My guess in the size planes you're talking about, I doubt you will use 100 MaH of capacity per flight for ignition power.
LiPo batteries are also very common but I'll let someone else verse their advantages, disadvantages. Most people prefer to remove these from the airframe for charging and storage.
Excellent LiFe battery tutorials at NOBS batteries:
http://www.hangtimes.com/nobsbatteries.html