Prolonging Lithium-ion battery life: what should I do?

Question

There are many suggestions about lithium ion battery:

1. Prevent over-discharging. Cell reversal can cause an electrical short.

2. It is good for the battery to be completely discharged every so often, about once a month.

3. Q: Should I totally discharge, then recharge my Dell laptop battery occasionally to make it last longer? A:No, discharging and charging does not increase the life of a Lithium Ion technology battery.(Dell FAQ)

4. To use a laptop on battery or AC adapter, it won't make all that much difference. What will shorten battery life is temperature.

5. Most users do not remove the AC power and I like to believe that this practice is safe.

6. Battery should be periodically charged and discharged between 20%-100%, it will extend battery life.

7. Depth in cycle decreases capacity.

   ---

    Depth of discharge(DoD)                     Discharge cycles
   --------------------------------------------------------------
    100% DoD                                    500
   --------------------------------------------------------------
    50% DoD                                     1500
   --------------------------------------------------------------
    25% DoD                                     2500
   --------------------------------------------------------------
    10% DoD                                     4700
   --------------------------------------------------------------
   

If I can keep the temperature at desired level, what about the conflicting suggestions (e.g. 5 vs 6) mentioned above????

Answer 1

"Lithium Ion" is actually a broad family of battery technologies. That said, they all break down due to currents. This means discharge/charge cycles only hasten the demise. In comparison, charging lead-acid batteries may break up lead-sulfur deposits. That's why they do benefit from a discharge/charge cycle.