Useful life of Li-Ion only 2-3 years from when manufactured?

[L_D_Allan]

I came across the following statement in a photography forum, and wanted to check on its validity:
> "Lithium Ion batteries have a limited lifespan of 2-3 years (from time of manufacture)."
http://www.dpreview.com/forums/post/56787829

My less-than-informed impression was that well made, non-abused Li-Ion batteries for typical digital camera use have a much longer life. Typically, they can be expected to recharge 1000+ times.

Or not?

 

[ChrisGarrett]

Ehhh, it was accepted that anywhere from 3-5 years and that li-ions start degrading once off the production line and whether they're used, or not.

The real trick is in how they're stored when not being used, or even when used.

Don't store them in temps much over 80*F, don't store them for extended periods of time at 100%/4.2v, don't discharge them down much below 3.0v as a rule and don't run them at their redline, as far as current load goes.

I'm using Sony 2100mAh 18650s that are date coded 2002, from a VAIO laptop that my brother bought back in 2004-ish. They hold steady at 4.15v, 4.14v for months, so they're still viable.

That's almost 14 years.

Chris

 

[Gauss163]

I'm using Sony 2100mAh 18650s that are date coded 2002, from a VAIO laptop that my brother bought back in 2004-ish. They hold steady at 4.15v, 4.14v for months, so they're still viable.

One needs more data than that to prove they are in good health. They may have internal resistance so high that they have little capacity left except at tiny current. They may have lost much capacity due to internal parasitic reactions (which increase with higher temp and higher voltage).

But it is true that well-maintained cells can have a very long storage life - perhaps up to a decade. For example, this JPL/NASA study presented Li-ion cells retaining over 90% of initial capacity in 4 years storage, as long as the storage temp was < 40°C (104°F). Many other studies show similar results.

Keep in mind that the industry standard definition of end-of-life is when the cell reaches 80% of initial capacity. However, at this point, one can still make use of the cells in lower-drain devices (which don't suffer as much the effect of high internal resistance - the primary degradation mechanism).

 

[ChrisGarrett]

One needs more data than that to prove they are in good health. They may have internal resistance so high that they have little capacity left except at tiny current. They may have lost much capacity due to internal parasitic reactions (which increase with higher temp and higher voltage).

I'm not trying to prove anything to anybody and certainly not you.

I was just telling the OP that cells can be used that are way older than 3 years.

My 2002 Sonys have about 25% diminished capacity, they don't get hot, or even warm when charging at 500mA, they don't self-discharge more than .01v over say a two month period and at about a 1A+ draw, they last at least 90min.

They're more than fine in the moderate loads that I place them in.

Chris

 

[m4a1usr]

I came across the following statement in a photography forum, and wanted to check on its validity:
> "Lithium Ion batteries have a limited lifespan of 2-3 years (from time of manufacture)."
http://www.dpreview.com/forums/post/56787829

My less-than-informed impression was that well made, non-abused Li-Ion batteries for typical digital camera use have a much longer life. Typically, they can be expected to recharge 1000+ times.

Or not?

I wonder if they are making that statement using the "Lap Top" battery logic on pack longevity? You find similar statements from lap top manufacturers regarding warranty or expected life time of battery packs. And that's primarily due to lap tops normally being plugged in all the time and in a continuous charging cycle or always in a fully charged condition. If folks would read up on this they would realize that its not harmful at all to let their lap top packs go down to a state where the indicated charge is well below the half way mark and it is proven for healthy for packs to drop down. Lap tops can be operated with the pack being charged so its most likely people being lazy or uninformed.

That's why we in the RC world, with very, very expensive lithium polymer packs, ALWAYS store our packs at 3.5 to 3.7 volts or less than 50% capacity. We know not to keep our packs fully charged year round. Now while lithium polymer packs are slightly different cell technology its safe to consider using the same storage conditions so that one will indeed get hundreds of charges out them.

I guess what I'm saying is that the statement made on the photo site may not be too far from the truth. Since cameras need to be used on a moments notice and in a fully charge state it would tend to agree with the issues seen in the lap top industry.

 

[Kurt_Woloch]

Well, as they say, it depends... not all batteries are created equal, and not all batteries are cared for equally. It also depends on how heavy they get used and what you define as end-of-life...

1000 charge cycles may be true, and 2-3 years may be true as well... that in itself doesn't contradict itself if you consider the case where a battery gets recharged every day, then you have 1100 cycles in 3 years. However, it doesn't mean that if that same battery only gets cycled only once a week, it will last for the same 1000 cycles, because that would be 20 years, and here the calendar loss also comes into play.

So there are two factors to battery degradation- calendar life and charge cycles. Calendar life, but also the number of charge cycles depends on how hot the environment is (both in use and under storage). Calendar life also depends on the state of charge the battery is kept in, with 100% yielding the lowest life. Cycle life depends on how high the battery is charged up... a charge to 100% is much harder on the battery than a charge of 90% or 80%, and going down to 0% also harms the battery more than keeping it at 10% or 20%, though maybe not as much as the "high end" of 100%. Then useful life may be hampered by the internal resistance getting higher and higher... the capacity may still be at 50%-80%, but the internal resistance will be so high that the device can't make use of the whole charge anymore, or shuts down spontaneously under high load because the voltage sags too much then.

Finally, battery life also depends on the chemistry... some batteries are optimized to withstand many charge cycles or high temperatures. Think of electric cars... if they would kill their battery, which costs thousands of dollars, in 2-3 years, they would become highly unrentable compared to gasoline cars. On laptops and phones it isn't that severe because the battery is much cheaper, however, in the case of non-replaceable or only factory-replaceable batteries, manufacturers typically take better care of offering more charge cycles, say 1000 instead of 300-400.

Just for the record, I have already experienced the following things:
- The battery that came with my used laptop was about 3-4 years old and had just a few cycles on it (3-5), but was still down to half its original capacity due to having been kept at 100%
- The replacement battery I bought then in April 2012 now holds at about 80% of its nominal capacity and 440 charge cycles.
- Another battery I got with another laptop is from 2009 (six years old), has got 8 charge cycles on it, but still about 90% of its nominal capacity and a remarkable low internal resistance... this one apparently has been taken care of well.
- The battery of a laptop of a colleague is pretty much shot after 3 years... he's been using it regularly in meetings, and now although it still shows about half of its nominal capacity, it actually shuts down after only half the time due to internal resistance
- Finally, the original battery of my father's mobile phone was finally replaced in June. It still worked after about 10 years, but was down to about half an hour of talk time and got very hot when charging (probably due to high internal resistance).

So as you see, all kinds of scenarios are possible.

 

[TinderBox (UK)]

I found this lecture on li-ion battery life, it`s a bit boring for some but i enjoyed it and learned a lot.

https://www.youtube.com/watch?v=9qi03QawZEk

John.

 

[Timothybil]

Another thing to remember is different usage patterns. A rechargeable cell used in photography will face short bursts of relatively high drain, sometimes one right after the other, sometimes spaced out. As such, they would be more vulnerable to high internal resistance than a cell used for longer periods of time at a lower drain. On the other hand, cells used in flashlights and laptops face for the most part a lower steady drain.
Also, unless one is using an external battery pack, cells used in photography tend to be smaller - 14500, RCR123, 18350, etc. Exceptions would be things like a large 'potato masher' flash unit, or a multiple flash head setup, that would tend to use one or more 18650 type cells.
Lots of things to take into consideration.

 

[Dex Robinson]

I'm big into photography (started doing my own dark room as a jr.high school student in the early 1970's). I'm a member of the dpreview forums.

I can tell you that I have a 9 year old Li-ion battery installed in a camera right now (I just checked) and it gets regular use. In fact, now that I think about it, the three batteries for my Olympus DSLRs are 9, 7 and 5 years old respectively and all are still quite reliable. I haven't done a capacity check and I'm sure they are losing capacity but it's not enough of an issue to cause a problem. For my other cameras, the batteries are between 5 and 1.5 years old. NONE have failed. Again, I'm sure there is some degradation but it hasn't been an obvious problem.

This subject comes up on dpreview quite often. There are people who are convinced a Lithium battery won't last 5 years and, when I first got into high-end digital photography, I was concerned. It's not something I worry about anymore.

 

[etc]

I stripped out a bunch of 18650s out of used laptop batteries. More than 5 years ago. Maybe about 200 cells total, around 40% did not hold charge. The rest still do. I estimate these cells to be about 10 years old now. I have no idea how much total charge they hold. But they do light up all the modules I have for a while.

 

[L_D_Allan]

Thanks all for the useful and helpful replies.

 

[LiteTheWay]

The first Li-ions I got were AW18650 - seven or so years ago and still going strong without any sign of degradation.

 

[etc]

I have 2200 mAh AW protected cells, 18650s, I think I've had them for about 6-7 years. They went bad, don't hold charge. I have older cells than that, 12+ years old that do hold charge. It's chinese vs. japanase. The newer generations of AW cells - 2600 mAh and up - are japanese and keep going strong like the other laptop cells I have.

 

[TinderBox (UK)]

Yeah, I just had to recycle a couple of protected 700mah AW RC123 cells as they would only hold around 50mah i have had them for 5+ years and they had been heavily used, the flashlight regulated the voltage so i only knew the battery was low when the protection circuit kicked in at 2.5volts , So i am quite happy with the cells.



John.