Hi everyone,
I have a question regarding the minim voltage of LiPos and Li-Ions.
I know that the minimum safe voltage for a LiPo is about 3.5 V/cell, while for a Li-ion is around 3.0 V/cell.

However, I noticed a voltage sag of about 0.2 V/cell while flying my Li-ion 4S pack: in fact, after taking off, the voltage goes instantly from 4.00 V/cell to 3.8 V/cell (probably my voltmeter is off scale by 0.1 V, since I charged the battery less than 10 hours before the flight and the charger showed 4.1 V/cell).

With the Li-ion pack I should have got to 20 minutes flight time; however, since I had to land at 3.00 V/cell, I only got about 10 minutes of flight time. After connecting the Li-ion pack to the charger, I noticed it was still at 3.5 V/cell, probably due to the voltage sag, so I could have got to the 20 minutes flight time with those remaining 0.5 V/cell.

My question is: if I know that I have a voltage sag of 0.2~0.3 V/cell, is it safe to land at 2.7~2.8 V/cell, knowing that without load the pack would stay above 3.0 V/cell? Or will I risk to permanently damage the Li-ion pack if I go below 3.00 V/cell, even if I take into account voltage sag?

Does the same apply also for LiPos? (for example, landing at 3.3 V/cell instead of 3.5 V/cell)

Thank you in advance.