LiPos really hate being over discharged. Proper operating voltage for LiPos are from 2.8v (nearly dead) to 4.1-4.7v (fresh off the charger) per cell. Most guns aren't efficient enough to over discharge a LiPo, but it can happen. The easiest way to keep your LiPos in good condition is to get a lipo tester. LiPo testers are used but plugging the external prongs into the balance charge plug of the lipo pack. The tester will then light up red and chime, indicating that it has sufficient power to turn on, and then the lights will change. If any the lights stay red and the tester continues to chime, you must re charge your battery pack. If the lights turn green (one for each cell of your LiPo pack) your battery is still good to continue using. The testers are set to chime and turn red at 3.2v, so there is room for error before the battery drops below 2.8v. These testers have reverse polarity protection, so it doesn't matter if you accidentally plug it in the wrong way.