jdetray

Hi 6pack-

1. To maximize the life of your lipos, it is best to let them cool down before charging. If you understand that you may be shortening the life of your lipos, charging a slightly warm battery is OK. Do NOT charge a battery that is hot to the touch. In fact, if you have batteries that are getting hot, you should find out why and correct the situation.

2. Lipos slowly lose capacity over time. Abusing them by drawing excessive current or discharging them too far will speed up the loss of capacity. A properly cared for lipo will last hundreds of flights.

3. The electronic speed controller (ESC not ECS) can probably handle the higher voltage of a 3-cell lipo; you should be able check with the manufacturer. The motor is more of a question. Sometimes, you have to run a smaller prop to reduce the current if that type of motor is to survive the move to 3S lipos.

4. Over-discharging a lipo is probably the worst thing you can do to it. It causes permanent changes in the cells that often cannot be undone. A lipo sould never be discharged below 3V per cell. That's 6V for a 2-cell lipo, 9V for a 3-cell lipo.

The 3V per cell rule is for UNDER LOAD conditions. In other words, you don't want the voltage to drop below 3V per cell at any time, including in flight. An obvious problem is that most of us don't have a way to measure the in-flight voltage.

The solution is to check the battery voltage after flying and after giving the pack a few minutes to recover. This so-called "resting" voltage gives you a good idea of how far your lipo has been discharged. Borrowing from the table [link=http://www.rcgroups.com/forums/showpost.php?p=3272601&postcount=11]here[/link], if the resting voltage of a lipo is near 3.6V per cell (7.2V for a 2-cell pack), it is fully discharged. If the resting voltage is less that 3.6V per cell, the lipo has been over-discharged.

By comparison, a fully charged lipo will be about 4.2V per cell, or 8.4V for a 2-cell pack.

- Jeff