Self discharge rate of lithium batteries (like 10440s)?

[Ice]

I've heared a lot of lithium batteries here in the forum and I'd like to ask what self discharge rate those usually have (especially the 10440-AAA-type ones but also e.g. 18650s).
I usually associate rechargeable lithium batteries with mobile phones and laptops, and those usually loose their charge extremely fast! Are those 10440s different? And in what way?
Thanks!

 

[2xTrinity]

I've heared a lot of lithium batteries here in the forum and I'd like to ask what self discharge rate those usually have (especially the 10440-AAA-type ones but also e.g. 18650s).
I usually associate rechargeable lithium batteries with mobile phones and laptops, and those usually loose their charge extremely fast! Are those 10440s different? And in what way?
Thanks!

The difference with mobile/phones and laptops is that there the device is never completely "off". There is usually always some background power draw to keep thing stored in memory, or taken up by the regulator circuits. Bare LiIon cells actually have fairly low self-discharge, and should retain most of the charge even when sitting for months.

 

[SilverFox]

Hello Ice,

I ran a test on an unprotected 18650 cell for one year. Here are the results of the test. I believe I lost around 5% in one year.

Protected cells may self discharge faster because there is a small draw on the cell from the circuit. Published information often suggests around 1% per month.

Tom

 

[Ice]

Thank you very much, good to know that! :bow:

One more thing:
I know there are lithium ion and lithium polymer batteries. Which ones are the usual batteries we're talking about here?

 

[TigerhawkT3]

Thank you very much, good to know that! :bow:

One more thing:
I know there are lithium ion and lithium polymer batteries. Which ones are the usual batteries we're talking about here?

Lithium-Ion. Lipos are the ones that are usually used in RC applications, as they come in many different shapes.

 

[SilverFox]

Hello Ice,

Li-Po is short for Li-Ion Polymer. Both types have very similar chemistry, but are built differently.

The general rules for Li-Ion also apply to Li-Ion Polymer, and visa versa. The big difference is that Li-Po cells are capable of much higher charging and discharging currents.

Tom

 

[BUZ]

Hello Ice,

I ran a test on an unprotected 18650 cell for one year. Here are the results of the test. I believe I lost around 5% in one year.

Protected cells may self discharge faster because there is a small draw on the cell from the circuit. Published information often suggests around 1% per month.

Tom

Wow thats pretty good!

 

[Handlobraesing]

Self discharge on a lithium cell is very low, but also permanent.

If you store them fully charged, what's lost after a year is not recoverable from charging.

 

[Lite_me]

Self discharge on a lithium cell is very low, but also permanent.

If you store them fully charged, what's lost after a year is not recoverable from charging.

I've read that they should be stored at approx. 40% charge to preserve them, but I've never heard it stated this way. Interesting.

 

[4sevens]

Self discharge on a lithium cell is very low, but also permanent.

If you store them fully charged, what's lost after a year is not recoverable from charging.

Can you cite your source for this claim?

I had some very old AA lithium-ions that were at 4.25v a year ago that
I just charged up. They were 3.96 and now they are up to 4.2v and holding
their V after a week.

 

[Handlobraesing]

Can you cite your source for this claim?

Definitely.
http://www.batteryuniversity.com/partone-19.htm
"recoverable capacity after one year at 25°C storage & 100% charge level"
80%

There's also a reference on batteries called the Battery Handbook that contains a similar information. I'm sure Georgia State University has a copy.

I had some very old AA lithium-ions that were at 4.25v a year ago that
I just charged up. They were 3.96 and now they are up to 4.2v and holding
their V after a week.

Voltage merely refers to state of charge and doesn't show the capacity. A 12,000mAh and 360mAh battery would have the same voltage.

Have you run an Ah and Wh test from full charge to empty before storage and the same test a year later?