Originally Posted by CPF Min Voltage Thread

Post #6:
It is especially true for li-ion to not go below the cut-off voltage. Li-po's have almost no voltage sag and are pretty safe to say idle voltage=state of charge=running voltage (at least at a drain of less than about 2-3C). But with a larger sag in voltage of the li-ion you can get small areas inside the battery to destabilize and on the subsequent recharge you can get a puffing, in li-ion's case venting. I've seen as little as 3 cycles below 3 volts/cell puff a lipo, so it's best to not go below 3 volts. 2.75 is just too close to pushing it over the edge where a recharge can vent.

Post #7:
Hello AilSnail,

There are some "general rules" about depth of discharge with Li-Ion cells. These "general rules" are designed to maximize cycle life.

At the end of the discharge, when the load is removed from the cell, you will get better cycle life if the voltage rebounds to around 3.5 volts or higher.

The cut off voltage to make this happen depends on the load on the cell. Normal loads may use a cut off of around 3.2 volts per cell. High loads may be able to get away with a slightly lower cut off voltage. Light loads need a higher cut off voltage.

Charging efficiency with Li-Ion chemistry is nearly 100%. If you have a charger that tells you how much capacity has been put into the cell, you can adjust your usage so that you are using 80% of the cells total capacity. This will keep you from over discharging your cells and will give you excellent cycle life.
Tom

Post #9:
AilSnail;
The quality Li-Ion cells like Sanyo, Sony and Panasonic are not harmed by 3.0 volt discharge.
Most of the Chinese cells are questionable, even when only discharged to 3.5 volts.
I've used hundreds of the quality cells over many years.
Larry