How have you found battery life with the Falcon? I have one of the M4s and it burns through a lipo in a morning.
You're missing important points out of your message...
# What's the mAh of the battery?
# How many BBs do you believe you've shot when using it for a morning?
# Exactly what voltage is the battery at at the end of the morning?
# Is your DE M90X rifle stock? (have you made any changes to it).
... otherwise others can't reply with accurate comments.
Personally I've had no problems at all with batteries and the Falcon controller, but people must understand that it IS NOT a GATE Titan, it's battery management is crap compared to the real deal where you can set custom values. Double Eagle have directly told me that the battery protection will let a LiPo batteries cells go below 3.2 volts, and this will more than likely cause permanent damage to them, before the low cell voltage protection kicks in.
On Reddit I've argued with people claiming that the Falcon kills batteries, but in and of itself it does not, it's the player not using a battery with an high enough mAh and expecting the gun to cover their arse with it "magic fairy dust".
For me, when running a DE M904E as an AEG in skirmishes (I don't play milsim), I'll often get through 1,500 or more BBs, and I'll take a 3,000 mAh Titan LiIo down to around 3.4v per cell. I'd say that if you're maybe shooting 1,000 BBs a morning you'd want a minimum of 1,450 mAh on an 11.2v otherwise you'll run dry and potentially cause permanent battery damage.