LiIon batteries: What counts as a charge-discharge cycle?

Mar 23, 2010 4 Replies

LiIon batteries are said to have a finite number of charge-discharge cycles built in to them. I've seen some claims that ANY application of charge, regardless of the initial state of the battery, counts as one.



We were all taught to run our NiCd batteries down to near exhaustion before charging them to avoid the dreaded "memory effect"; should we treat LiIons the same way to avoid using up their cycles?


Bert Hyman St. Paul, MN bert@iphouse.com

I would say no to this. on my macbook pro, I can see when the cycles number changes and it needs a certain amount of charge to do so only charge a little doesnt increment the number of charges cycles.

Jean-Yves.

--- Said by whom?

As far as I know, lithium ion cells have a finite number of charge-discharge cycles, but the number depends largely on how they're used and the environment in which they're used as opposed to an arbitrary number purposely "built" into them.

---

--- Cite your source?

---

--- No.

Discharging LiIOns below a lower limit, like lead-acid batteries, can permanently damage them.

formatting link

JF

The popular press.

The all-knowing "they," as in "they said ..."

Bert Hyman St. Paul, MN bert@iphouse.com

This does not directly answer your first question, but it is instructive reading:

formatting link

To answer your second question (and based on the above) deep discharge of lithium-ion batteries (even within the safe limits usually enforced by protection circuits built into commercial packs) shortens their useful life.

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required