Li-ion storage advice?

One of the things I've always loved about Lithium Ion batteries
(compared to NiMH) is their very low self discharge rate. Put it in a
drawer for 6 months and sill have a usable charge it it.

Also the total lack of memory effect. You can charge/discharge them
without regard to "harming" the cells in some way, other than normal wear.

I've read different advice on how to store Li-ion batteries, from
freezing to always storing filly charged. Doing a Google search these
days seems to yield the general advice to discharge them to 40% for long
term storage.

And under no circumstances should they be allowed to fully discharge as
a special protection circuit needs a bit of remaining juice or it may
malfunction and prevent the cell from ever being charged again.

So it was with great amazement I read this in the Canon manual for my
new S100 camera.

"How to store the battery for long periods: Deplete and remove the
battery from the camera. Attach the terminal cover and store the
battery. Storing a battery for long periods of time (about a year)
without depleting it may shorten its life span or affect its performance."

So what's the general advice these days? Do you agree with Canon's
advice to store Li-ion batteries completely discharged?

Bruce.

In article , Bruce.
wrote:

One of the things I've always loved about Lithium Ion batteries
(compared to NiMH) is their very low self discharge rate. Put it in a
drawer for 6 months and sill have a usable charge it it.

Also the total lack of memory effect. You can charge/discharge them
without regard to "harming" the cells in some way, other than normal wear.

I've read different advice on how to store Li-ion batteries, from
freezing to always storing filly charged. Doing a Google search these
days seems to yield the general advice to discharge them to 40% for long
term storage.

you want it somewhere in the middle. 40% is close enough. fully charged
or fully discharged is bad for storage.

And under no circumstances should they be allowed to fully discharge as
a special protection circuit needs a bit of remaining juice or it may
malfunction and prevent the cell from ever being charged again.

you can't fully discharge a lion battery. the protection circuit will
kick in and prevent it. however, discharging it at low as it goes is
still bad for long term storage.

So it was with great amazement I read this in the Canon manual for my
new S100 camera.

"How to store the battery for long periods: Deplete and remove the
battery from the camera. Attach the terminal cover and store the
battery. Storing a battery for long periods of time (about a year)
without depleting it may shorten its life span or affect its performance."

is it a lion battery or something else?

So what's the general advice these days? Do you agree with Canon's
advice to store Li-ion batteries completely discharged?

if it's lion, definitely not. discharge them to 50% and put into
storage.

Bruce. wrote:
One of the things I've always loved about Lithium Ion batteries
(compared to NiMH) is their very low self discharge rate. Put it in a
drawer for 6 months and sill have a usable charge it it.

Also the total lack of memory effect. You can charge/discharge them
without regard to "harming" the cells in some way, other than normal wear.

I've read different advice on how to store Li-ion batteries, from
freezing to always storing filly charged. Doing a Google search these
days seems to yield the general advice to discharge them to 40% for long
term storage.

And under no circumstances should they be allowed to fully discharge as
a special protection circuit needs a bit of remaining juice or it may
malfunction and prevent the cell from ever being charged again.

So it was with great amazement I read this in the Canon manual for my
new S100 camera.

"How to store the battery for long periods: Deplete and remove the
battery from the camera. Attach the terminal cover and store the
battery. Storing a battery for long periods of time (about a year)
without depleting it may shorten its life span or affect its performance."

So what's the general advice these days? Do you agree with Canon's
advice to store Li-ion batteries completely discharged?

Bruce.

I too have a Canon S-100, which I like very much. Have you ever thought
of posing your question to Canon's Tech Support people? In addition to a
reply that might possibly be helpful, you can print out their e-mail
response and keep it with your owner's manual, in case a problem with
the battery arises. A piece of paper might be more useful than a
telephone conversation.

Regards,

Mort Linder

On 4/3/2012 7:07 PM, nospam wrote:
is it a lion battery or something else?

Yes, Canon NB-5L Li-Ion Batteries.

Bruce.

On 4/3/2012 7:20 PM, Mort wrote:
I too have a Canon S-100, which I like very much. Have you ever thought
of posing your question to Canon's Tech Support people? In addition to a
reply that might possibly be helpful, you can print out their e-mail
response and keep it with your owner's manual, in case a problem with
the battery arises. A piece of paper might be more useful than a
telephone conversation.

Good idea! I didn't know they had email support which I just found. I
have sent them the same question and will post the reply. I don't
expect them to contradict their camera manual but the reply might be
enlightening in some way.

Bruce.

On 4/3/2012 7:07 PM, nospam wrote:
you can't fully discharge a lion battery. the protection circuit will
kick in and prevent it. however, discharging it at low as it goes is
still bad for long term storage.

From what I read, which may be dated and no longer accurate, that while
the circuit prevents a short term full discharge, if the battery is
fully discharged and then allowed to sit in that state for a long time,
the unavoidable self-discharge rate will continue to deplete the battery
below what is needed for the circuit to work, although that may take
many months longer, making it impossible for most battery chargers to
recharge it.

They also mentioned that there are special chargers available that can
recharge such "dead" batteries despite the non-functional protection circuit

Bruce.

On 4/4/2012 9:13 AM, Bruce. wrote:
Good idea! I didn't know they had email support which I just found. I
have sent them the same question and will post the reply. I don't expect
them to contradict their camera manual but the reply might be
enlightening in some way.

Well, not too surprisingly, the basically restated what the manual says.
They do get high marks for a very fast reply though! Here is the reply:

"To store the battery pack it is recommended that you deplete the power
and remove the battery from the camera. Attach the terminal cover (or
place the battery pack in a zip lock style bag) and store the battery.
Storing it for a long period of time without depleting it may shorten
its life span or affect its performance. If you do not use the battery
for long periods of time, charge it fully and discharge it fully in the
camera about once a year before returning it to storage."

To the advice in the manual, they added the requirement that the battery
in storage be fully charged and then fully discharged about once a year.

So Canon seems to disagree with the general Li-ion advice I've read
elsewhere.

Bruce.

"Bruce." writes:

So it was with great amazement I read this in the Canon manual for my
new S100 camera.

"How to store the battery for long periods: Deplete and remove the
battery from the camera. Attach the terminal cover and store the
battery. Storing a battery for long periods of time (about a year)
without depleting it may shorten its life span or affect its
performance."

So what's the general advice these days? Do you agree with Canon's
advice to store Li-ion batteries completely discharged?

It may not be the same for all Li-ion batteries, either. Either the
underlying battery tech, or the layer of management circuitry on top,
may be different, causing different recommended storage procedures.

I'd need pretty strong reasons to ignore specific instructions for my
exact battery.
--
David Dyer-Bennet, ; http://dd-b.net/
Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/
Photos: http://dd-b.net/photography/gallery/
Dragaera: http://dragaera.info

On Wed, 04 Apr 2012 09:33:40 -0500, "Bruce."
wrote:

On 4/4/2012 9:13 AM, Bruce. wrote:
Good idea! I didn't know they had email support which I just found. I
have sent them the same question and will post the reply. I don't expect
them to contradict their camera manual but the reply might be
enlightening in some way.

Well, not too surprisingly, the basically restated what the manual says.
They do get high marks for a very fast reply though! Here is the reply:

"To store the battery pack it is recommended that you deplete the power
and remove the battery from the camera. Attach the terminal cover (or
place the battery pack in a zip lock style bag) and store the battery.
Storing it for a long period of time without depleting it may shorten
its life span or affect its performance. If you do not use the battery
for long periods of time, charge it fully and discharge it fully in the
camera about once a year before returning it to storage."

To the advice in the manual, they added the requirement that the battery
in storage be fully charged and then fully discharged about once a year.

So Canon seems to disagree with the general Li-ion advice I've read
elsewhere.

Bruce.


I wonder if they (Canon) are thinking that the camera will only
discharge the battery to a certain point, not fully discharge it as
would a flashlight.

On 4/4/2012 2:01 PM, charles wrote:
I wonder if they (Canon) are thinking that the camera will only
discharge the battery to a certain point, not fully discharge it as
would a flashlight.

Possible. Another thing the manual says it the camera's current
date/time will only last about 3 weeks if the Li-ion battery is removed.
After that the date/time will need to me manually set again next time
it's powered up.

That implies that so long as the battery is installed the camera is
drawing some current to keep the date/time updated. But since my
current watch battery lasts 10 years, I'd guess the current needed is
extremely small.

Bruce.