Paulo Lai
29-11-2003, 08:49 PM
For more than you ever need to know about batteries, I found this site good-
http://batteryuniversity.com/
The relavent pages in this case are -
http://batteryuniversity.com/partone-5.htm
"Aging is a concern with most lithium-ion batteries and many manufacturers
remain silent about this issue. Some capacity deterioration is noticeable
after one year, whether the battery is in use or not. The battery frequently
fails after two or three years. It should be noted that other chemistries also
have age-related degenerative effects. This is especially true for
nickel-metal-hydride if exposed to high ambient temperatures."
And How to store batteries -
http://batteryuniversity.com/partone-19.htm
It seems like sometimes you get a good one and I have heard reports of some
that don't degrade much over time, however in most cases it seems they are
optimised for capcity when you buy it then capacity three years down the
track. Most telling is how you can almost never find anyone selling you
warranty for li-ion batteries, with IBM and others considering them to be
a consumable.
Paulo
On 27/11/2003 18:03, aaardvaark wrote:
> Hey Simo! <<<Don't want to start anything but this is utter
> nonsense.>>>
>
> This is a bit strong! I think the most we can say is that the jury is
> out. I have seen the statement that Li-ion cells have low life (not
> cycles-type life, but years-type) several times, the last was in the
> current "Digital Photographer" Issue 11 page 70. "..one of the least
> known and most significant facts about lithium-ion cells, though, is
> their limited shelf life of 2 or 3 years, regardless of whether you use
> them or not."
>
> I have googled my way through a few sites to come up with a lot of
> contradictory thoughts, some of which I copy below. It seems that
> perhaps some people mix lithium batteries with lithium-ion, and it also
> seems that Litium-ion batteries are developing in recent years to
> improve shelf life, but are not there yet.
>
> Maybe the most telling quote below is the NASA one which says it is
> going to study the matter because there is little data at this time.
>
> Most of the quotes below support my statement, but I found at least as
> many saying the opposite, so I guess we don't know apart from real life
> experience like yours.
>
> BTW I'm also an electrical engineer, but have no 5 year old Li-ion
> batteries at home! Maybe yours are defence quality and thus more
> recent technology???
>
> I'm glad you pulled me up though, now I know that it is not black and
> white, so thanks.
http://batteryuniversity.com/
The relavent pages in this case are -
http://batteryuniversity.com/partone-5.htm
"Aging is a concern with most lithium-ion batteries and many manufacturers
remain silent about this issue. Some capacity deterioration is noticeable
after one year, whether the battery is in use or not. The battery frequently
fails after two or three years. It should be noted that other chemistries also
have age-related degenerative effects. This is especially true for
nickel-metal-hydride if exposed to high ambient temperatures."
And How to store batteries -
http://batteryuniversity.com/partone-19.htm
It seems like sometimes you get a good one and I have heard reports of some
that don't degrade much over time, however in most cases it seems they are
optimised for capcity when you buy it then capacity three years down the
track. Most telling is how you can almost never find anyone selling you
warranty for li-ion batteries, with IBM and others considering them to be
a consumable.
Paulo
On 27/11/2003 18:03, aaardvaark wrote:
> Hey Simo! <<<Don't want to start anything but this is utter
> nonsense.>>>
>
> This is a bit strong! I think the most we can say is that the jury is
> out. I have seen the statement that Li-ion cells have low life (not
> cycles-type life, but years-type) several times, the last was in the
> current "Digital Photographer" Issue 11 page 70. "..one of the least
> known and most significant facts about lithium-ion cells, though, is
> their limited shelf life of 2 or 3 years, regardless of whether you use
> them or not."
>
> I have googled my way through a few sites to come up with a lot of
> contradictory thoughts, some of which I copy below. It seems that
> perhaps some people mix lithium batteries with lithium-ion, and it also
> seems that Litium-ion batteries are developing in recent years to
> improve shelf life, but are not there yet.
>
> Maybe the most telling quote below is the NASA one which says it is
> going to study the matter because there is little data at this time.
>
> Most of the quotes below support my statement, but I found at least as
> many saying the opposite, so I guess we don't know apart from real life
> experience like yours.
>
> BTW I'm also an electrical engineer, but have no 5 year old Li-ion
> batteries at home! Maybe yours are defence quality and thus more
> recent technology???
>
> I'm glad you pulled me up though, now I know that it is not black and
> white, so thanks.