Off, it will charge faster. Be sure to let the battery run completely empty every once in a while. Not a bad idea to leave it on the thursday before a weekend game, and charge it up that friday.
Reason for this has something to do with crystals building up in the battery or somethign or other... I know it prolongs the life of a battery... I don't think it maters with a lithium ion batter though. So you might be all set.
The problem with both of these types of bateries over NiCad os that they cannot be recharged as much (AKA they will only take a charge X times whereas NiCad can be recharged Y times more than LitOn/NmH which is worth the fact that you don't have to totally discharge them before recharging them)
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#46
if you are a paintballer from Satan's Army put this in your sig.
Letting it drain fully with the batteries spyder uses is not an issue. I'm not fully aware of the science, but one type of rechargables does have to be fully drained before recharging to prevent damage. Leave the marker off.