One can’t help but have a lot of respect for Illusion
due to the simple fact of all the help he has dished out here on the forum of very useful information and his experience of working with Airsoft. So when I say I don’t think he meant literally not to discharge your Li-Pol battery pack it’s not that I know him personally and have tons of experience on how to interpret what he says but rather it’s because of my understanding of how Li-Pol tech works.
To say to someone, “here’s your Li-Pol but don’t discharge it” is the same as saying don’t ever use it! To use a battery is to discharge it. What I think Illusion may have meant to say was don’t totally discharge a Li-Pol below a certain limit. And here’s is why.
The voltage of a Li-poly cell varies from about 2.7 V (discharged) to about 4.23 V (fully charged), and Li-poly cells have to be protected from overcharge (thought I would throw in the overcharge danger also) by limiting the applied voltage to no more than 4.235 V per cell used in a series combination. Overcharging a Li-poly battery will likely result in explosion and/or fire.
Next during discharge on load, the load has to be removed as soon as the voltage drops below approximately 3.0 V per cell (used in a series combination), or else the battery will subsequently no longer accept a full charge and may experience problems holding voltage under load.
Now the above information is dated and recent tech has somewhat changed in regards to Li-Pol but the relationship is approximately the same. Starting in about 2007 the early cells required longer charge times and slower maximum discharge rates. But recent improvements offer a much faster rate of charge with some cells taking only about 5 minutes to reach 90% of charge capacity and have increased maximum discharge currents from two times to 15 or even 30 times the cell capacity.
Thus it’s very important to read and be familiar with the details of your particular battery pack. And this topic is also a good argument on using a MOSFET that shakes your gun when the Li-Pol has became dangerously discharged to remind you to change the battery.
And even as I write this tech changes so fast these day this info may be outdated.