[bjsmith]

For a $1,500 body with $300-1,000 lenses attached, let alone my eye within an inch or two of the battery compartment, I really find it difficult to buy anything but the Pentax designed, tested and certified D-Li 90 batteries.

I bought two (2) more for $36/each at Amazon to add to the battery that came with my K5 Silver Limited. In AF.C mode over almost a full day I shot over 2,300 shots before it went to 2/3rds power. The next battery shot over 2,400 shots well into the 2nd day, before it went to 2/3rds power. Understand I was in AF.C the whole time, and easily had it beep over 10,000 times (if not more) autofocusing.

Kinda hard to get me to save $10-20 on a battery. It's one thing if these were Nickel-Ion batteries, which are fairly basic with no regulation per cell. But Lithium-Ion is another beast entirely, and the number of fabs that try to make "generic" designs that work across many different products are not quite the same.

[bjsmith]

I have been using them and chinese grips for years and no problems

Grips are a different story. Most grips use AA batteries in an arrangement that ensures nominal current and overall power. Six (6) or Twelve (12) NiMH AA batteries will provide either one or two, respectively, parallel lines of 7.2V nominal output in a grip.

[Osama Binhidin]

Lol ,it does not equate the price of lens and bodys and the price of batteries I also use them in the grip not aa batteries. the grip uses both types of batteries the original pentax battery is made in Vietnam plenty of others from the sme factory if you look around. The chinese ones I have are fine the exploding battry is an urban myth.

[jolepp]

Expoding battery or at least one getting very hot is *not* an urban myth as far as the physics of it go: that 14 Wh on the original equals to 14 x 3600 Ws = ~50 kJ. To give this some perspective a .308 bullet at muzzle velocity has about 3 kJ kinectic energy. Also, this would be enough to warm a cup of water (~1.5 dl) from room temperature to boing; water has quite impressive heat capacity, this would be enough to bring a 1kg piece of iron from 20C to >100C.

[Schraubstock]

Expoding battery or at least one getting very hot is *not* an urban myth as far as the physics of it go: that 14 Wh on the original equals to 14 x 3600 Ws = ~50 kJ. To give this some perspective a .308 bullet at muzzle velocity has about 3 kJ kinectic energy. Also, this would be enough to warm a cup of water (~1.5 dl) from room temperature to boing; water has quite impressive heat capacity, this would be enough to bring a 1kg piece of iron from 20C to >100C.

Hooly Dooly

Here comes the exploding battery again.
Oh dear oh dear, I can just picture it now. On my next outing little black mushroom clouds rising up to the sky everywhere. People running around with charcoaled faces holding the remnants of their camera in their hands. Television news crews don't come anymore because they have seen it so many times before and they know it only happens because people use generic batteries.

Also, men should not use overheating generic batteries in devices that are likely to come in contact with their reproductive organs as it will render them impotent.

Greetings

[Christine Tham]

My Ebay grip came with two spare batteries (7.4V 2000mAV) and I'm currently using both of them (one on the body, one on the grip) with no issues, and keeping the original battery as a spare.

I didn't really believe in the exploding batteries myth but last Sat whilst shooting the Zombie Walk with Nicole, the Aldi batteries in her Metz overheated (even though she said the flash was turned off) and were so hot we couldn't touch them with our bare hands, and they partially melted and deformed the battery compartment.

Pretty scary.

I hope that will never happen to my K-5.

[filorp]

they partially melted and deformed the battery compartment

because nimh battery doest have overcurrent protection (i suspect some short current in your case) and moste of the lithium used as power supply for electronics has some simple fuse.... they can give really strong current - one can weld with even used laptop batteries.

[Balog]

Hooly Dooly

Here comes the exploding battery again.
Oh dear oh dear, I can just picture it now. On my next outing little black mushroom clouds rising up to the sky everywhere. People running around with charcoaled faces holding the remnants of their camera in their hands. Television news crews don't come anymore because they have seen it so many times before and they know it only happens because people use generic batteries.

Also, men should not use overheating generic batteries in devices that are likely to come in contact with their reproductive organs as it will render them impotent.

Greetings

Batteries explosively failing is a well documented phenomena. Google it, or check out Candle Power Forum (problem seems more common in flashlights than cameras) for more details.

That being said, there are two vital points that are being missed.

1. It is not limited to generic brand batteries.
2. It generally involves abuse or misuse of the cell in some way.

I also note that while it is a real occurrence, it seems to have a very low rate. Hundreds of millions of cells have been produced, and there are a handful of documented instances of violent failure. Assuming that most failures are not documented, this still yields a few hundred or a few thousand at most, out of many millions produced. This seems to be an acceptable risk, to me.

[Schraubstock]

Hi Balog

Precisely, any technology can fail and a great percentage of this failure is attributable to human failure/mistakes/stupidity.

When something goes wrong it is human nature (in the first instance) not to blame themselves.

When a battery fails, first look at what you yourself may have done (not done) that may have caused the failure and when this brings up no clue perhaps then there is a rare case to be made to blame the battery integrity.

But please guys, don't scare the wits out of people with claims of exploding batteries (brand or generic).

Greetings from sunny Melbourne

[jolepp]

With the quality of some of the stuff enteprising people put together I would not be terribly enthusiastic about getting the cheapest possible battery; the said people would probably think of nothing of leaving out fuse(s) and other built-in safety measures to make things simpler/cheaper. I use 3rd party batteries though, in case I ran into one that claims a substantially higher capacity than the original I would not buy one, if a battery I bought would not seem to have the capacity stamped on it I would return (discard) it. Both of these, at least, would seem to mean that the maker does not mind selling counterfeit goods, so they might not be too particular otherwise. Having a considerable amount of energy to be released in a hurry at an inconvenient place/time does not sound like something I would like to risk especially when there are proper batteries at a reasonable price.

[Osama Binhidin]

Yes it is an urban myth, just like cell phones ringing or being used at service stations causing explosions with fuel vapour. lol this myth travelled so far, I think bp posted warnings only to be left with egg on their face when it was found to be an elaborate hoax

[Balog]

Yes it is an urban myth, just like cell phones ringing or being used at service stations causing explosions with fuel vapour. lol this myth travelled so far, I think bp posted warnings only to be left with egg on their face when it was found to be an elaborate hoax

This is factually incorrect.

Lithium explosion/fire thread


However, it is fair to say that the danger is greatly exaggerated, and not confined solely to generics. But to dismiss the fact that it has happened is equally incorrect.

Edit: more links regarding battery failure

[simico]

The genuine Pentax battery contains exactly the same standard cells as any other similar battery. You can buy the cells in reputable battery shops and replace them in a died battery - I know people who do this. In fact all these batteries for cameras and camcorders (and many other products) are manufactured in a few factories.

The thing with aftermarket / knockoff batteries is that many of them user cells that didn't quite passed QA in the factory - then you get those disappointing batteries that die very soon or give you pathetic results like only 1-200 shots with one charge. There are some reputable "brands" that use only good cells and in fact the only difference from a OEM battery is the sticker Unfortunately most of the exotic "never heard before" brands (that come and go quite fast) are not like that, they just use whatever crap they can find.

[eaglem]

Got this email today from a friend who deals with batteries:

Hi Bob,
We've busted three common rechargeable battery myths that could save you a lot of headache...

Myth #1 - Batteries must be completely flat before you can charge them

While this is true of older battery technologies, lithium-ion/polymer batteries which are used in most cameras and laptops today can be charged at any time without any negative effects. There is no need to wait until the battery is flat to charge it.

Myth #2 - The cheap batteries on eBay have twice the power of the batteries in the shop

Not many consumers are aware that it is common practice in China for manufacturers to mislabel their batteries with higher capacities. The reason they say, is because that's what the market "wants". It doesn't matter to them that the batteries have only half the capacity mentioned on the label.

How do we know this? Because it even happened to us. Our own manufacturer started sending us batteries that were mislabeled. Thankfully we picked up on it pretty quickly and fixed the situation.

To fit more power into a battery the battery must be larger in size to fit the additional battery cells. Don't be fooled by a battery claiming to have twice the power that has no extra size for the additional cells needed.

Myth #3 - Batteries deteriorate the more you use them

While technically true, more importantly for most people all batteries deteriorate with age REGARDLESS of how often you use them.

This means that from the minute a battery is made it begins to deteriorate slightly each and every day.

You will only notice the deterioration after 3-5 years when the battery will hardly hold any charge at all and need replacing.

If you are a heavy user (we're talking professional photographer type user here) then the heavy use will also shorten the batteries life. However for most people time will impact the batteries deterioration more than their use.


I thought it was worth a read.

[bjsmith]

Okay ... I'll do this only once ... hope it's worth it and doesn't fall on deaf ears ...

It seems there are batteries that are essentially counterfeit in the sense that the stated capacity is nowhere near of that reported,

But "what is capacity?!"

I've had this discussion over and over. I've yet to find another, fellow Electrical Engineer (EE) who disagrees with me, especially those with more experience in power systems (most often they entirely agree with me), whereas I have more exposure to microelectronics and semiconductor (and why variance in potential can kill microelectronics far quicker than the "extra pep" in the lens motors).

- "Charge" is just the alleged "Current-time" based on a load
- Many vendors quote "Charge" at a very minimal, not nominal, load -- like 100mA (whereas 1A+ is nominal)
- "Current" (real-time) is a function of not charge, but the remaining potential in the source for the load it was designed for
- As potential drops to meet "current" (real-time), you will lose functionality at a specific voltage cut-off, and will drop absolutely if the load is in excess of the design
- Pentax branded and certified batteries are designed for a specific potential-current over a specific current-time
- Generic batteries are not designed or certified for such, even when they come out of the same fab
- There is no "generic standard" for Li-Ion for all batteries -- e.g., no one supports/certifies "generic" Rechargeable CR-V3 batteries for a reason

This is the area of Lithium Ion (Li-Ion). Li-Ion is completely different than Nickel batteries, such as NiCD and NiMH. Li-Ion has regulated cells, regulation that is active enough to drain the battery. NiCD and NiMH just "leak" potential, but do not require the same cell-level regulation.

The fully charged voltages for the INOV8 batteries were both 8.0V, while the Pentax one was 8.35V
The former immediately dropped to about 7.5V, while the Pentax dropped to 8.0V. That is a big difference which suggests a much smaller battery (with a larger internal resistance) inside the package.

Not exactly.

What it means is two things:
1) Without a nominal load drawing current, the INOV8 was designed for a different potential
2) With a nominal K7/K5 load drawing current, the INOV8 is completely inadequate for the design

Potential is the issue. One can have a "smaller battery" and still be adequate. The overall "charge" (current-time) people speak of is not exactly.

What is exacting is how the real-time, actual potential-current output of the battery lasts over its total potential. The problem with so many "generic" batteries is that they are not designed for the end unit. There is a specific, real-time potential-current requirement over the potential of the battery, and when you don't design for such an end-unit, you get reduced longevity. This is still even the cause though the "charge" might actually be the same, using a minimal load, but not for the nominal charge of the unit.

I cannot stress enough there is a reason why no end-unit device supports "generic" Rechargeable CR-V3 batteries. Everyone designs and certifies a specific design. This is not Nickel battery technology at all. It's not non-rechargeable Lithium technology either (e.g., 3V LiMg in CR-V3 or 1.5V LiFe in Energizer Lithium). Lithium is an interesting beat, and Lithium Ion requires extensive microelectronics regulation and other details.

I don't know what the camera actually needs but the Pentax dropped quite rapidly at the very end from say 6.5V to 6V within 30 minutes so I regarded it as the end of its life.

The camera needs a specific real-time voltage-current (power). Voltage drops as a result of inadequate current, so current remains the same for the reduced, overall power.

It's bad enough if the battery does not even put out the potential required with no load. But with load, nominal load typical in a dSLR (1A+) and not just a common, minimal load that many use to rate "charge" (typically 100mA), the battery can still have a "lot of charge left," but be utterly useless because it can't provide enough current and, therefore, voltage that the load needs and constantly hit the devices cut-off voltage (so there is not a brown out).

I regularly used to take my alleged "dead" NiMH batteries out of my K100D and put them in reduced load (100-250mA) electronics and they'd work for another 4-10 hours. They literally had 1Ah (1000mAh) "left" in them. They just couldn't produce the required, real-time potential-current required for the K100D any more.

As I wrote, with an 11 ohm test load, and measuring the voltage.
There is no way to compare batteries on a camera because every small thing like the recovery time between shots will affect the total life.

Yes, to recharge various capacitance that are utilized in motors and other electronics, as well as select microelectronics. The CCD and shutter are of interest, beyond just the motors, although the motors are usually designed around the nominal input of the microelectronics, which are far more exacting.

I used to have this discussion with people who used "generic" Rechargeable CR-V3 batteries in their *ist-D, K100D, K200D, etc... where they'd basically talk about how much "pep" they had in their motors, and I'd try to get them to understand they are taunting their voltage regulators. Most everyone either reports infrequent to common "lock ups" (that "only" require a power toggle -- ummm, there's a reason for that, it's typically the voltage regulator doing its job) to sometimes lost shots or other issues to, and most commonly, far less shots than expected -- usually because the Li-Ion potential has been reduced by another load, and with it, overall, real-time current at the reduced, overall potential. I.e., not worth it in my book.

The only way to measure the real mAh capacity is to load it up and see how long it takes to run down.

Under the nominal load of the actual end-device, correct.

The INOV8 is about 1/3 of the claimed capacity. The Pentax did about 100% using the same method.

Which doesn't mean the INOV8 doesn't actually have its "claimed" overall "charge," it may very well be that it does.

It just means that under the actual, "nominal load" of the K7/K5, the INOV8 is unable to deliver the real-time potential-current over the life of the overall charge of the battery. It wasn't designed for the load, let alone it seems not the non-load potential in the first place.

That DPREVIEW article is interesting. All the batteries except Pentax and Hahnel are basically fakes because the shortfalls are too great to be production variations. INOV8 do not come out too bad; maybe the ones I have are duff.
I will get some Hahnel ones. Can anybody confirm the Pentax D-LI90 charger works well with them? I suppose one cannot be sure without doing a proper measurement.

Doesn't mean "fakes." It just means they were not designed to go in a K7/K5. With a different, real-time potential-current load, they may last longer.

It's the same reason why you see NiMH AA batteries with higher "charge" than LiFe AA batteries. Beyond the fact that the former are nominally 1.2V and the latter 1.5V, it's the fact that LiFe is able to deliver (according to Energizer) up to 2.6A nominal (let alone at 1.5V) than NiMH, which varies greatly. Some NiMH batteries can't even do 0.5A, while others easily do 1A+ as long as the battery has at least half its potential left (and then drops under). That's why for high current microelectronics, let alone those with motors, LiFe is preferred over NiMH.

At the same time, for a battery grip, if I put twelve (12) 1.2V NiMH batteries in two (2) series of six (6), I can get not only 7.2V nominal, but the two (2), parallel series circuits add together and I can get easily 2A+ for at least half their charge (series compounds potential, parallel compounds current).

Furthermore, if potential is the sole reason why batteries last "longer," then how come 1.2V NiMH AA batteries last longer than 1.5V Alkalines? Again, real-time current, as Alkalines often have trouble with more than 0.1A (let alone 0.5A), while NiMH is designed for 0.5A+.

The chinese ones I have are fine the exploding battry is an urban myth.

Good. I'll let you do an experiment where you reverse polarity with Nickel and Lithium-based compounds. You'll do the nickel first for a reason, because you will go to the hospital after you do the Lithium compound.

Nickel melts in the worst case, and is quite tolerant of various transients. Lithium cells COMBUST under polarity reversal, including varies transients that can and do occur. There is a reason why most Li-Ion designs have at least three (3) terminals, if not four (4). There are many transients and other issues with Lithium, especially changing from charge to discharge. That's one reason right there why the non-standard, "generic" Rechargable CR-V3s are not used, because CR-V3 only defines discharge (not charge), and there are non-standard designs for charging.

Lithium requires additional, cell-level regulation, in addition to the overall battery pack. Lithium Ion cells have active microelectronics that drain the battery when it's in non-use, unlike non-rechargeable Lithium compounds (again, LiMg for CR-V3, LiFe for Energizer Lithium) which "hold their charge" for decades. Lithium actually holds charges for decades, but the rechargeable Ion designs do not because of those active, regulatory circuits. Eventually individual cells fail over time, enough to a point the overall real-time current is inadequate. That's why Li-Ion batteries are only good for about 1-2 years of continual use and charging (500+).

because nimh battery doest have overcurrent protection (i suspect some short current in your case) and moste of the lithium used as power supply for electronics has some simple fuse.... they can give really strong current - one can weld with even used laptop batteries.

Again, Nickel and Lithium are completely different, one should never compare them.

Lithium is a high capacitance, but very fickle compound. Designs require a different potential for charging than discharging, and it has a very narrow potential band for both. This is partially due to the microelectronics that regulate its cells, as microelectronics often have a narrow band as well. Going too high over-volts circuits and, in the worst case, just makes a cell unusable. Going to far can cause the Lithium cell to combust, although the microelectronics is specifically designed to render it unusable instead. Going to low, the cell is destroyed -- either by the cut-off of the microelectronics or the common case of sub-3V being deadly to the Lithium compound itself.

SIDE NOTE: This is also why the "reduced voltage, generic" Rechargeable CR-V3 is almost self-defeating. CR-V3 is 3V nominal under load, but Li-Ion is nominally 3.7V. Trying to reduce it down to 3.3V or under brings it close to its "death voltage," so the microelectronics cut-off much sooner. It's also why the batteries tend to die quicker too, because the cut-off is not only so low, but when you store a Li-Ion cell at or below its 3V base, it tends to destroy the cells after a few months. Remember, the regulatory microelectronics are still draining it too, during storage.

Yes it is an urban myth, just like cell phones ringing or being used at service stations causing explosions with fuel vapour. lol this myth travelled so far, I think bp posted warnings only to be left with egg on their face when it was found to be an elaborate hoax

The four most common reason for combustion at refilling stations are:

1. Mechanical (overwhelmingly, typically 1 sigma or at least 2/3rds to 80%, failures of the pumps, agitation, spark, etc..)
2. Exposed flames (i.e., mainly smokers, not as high as you would expect, but still significant)
3. Electro-static (almost as much as smokers, people not grounding themselves, opening doors while filling, etc...)
4. Electro-magnetic (very low, but still as much as 1%)

Yes, it's rare that a 700MHz - 2.1GHz signal would cause any type of EMF and resulting EMI. However, it's still possible. It's more of an issue at a refueling station than on an airplane, because you do have vapors that are openly exposed to an endless supply of oxygen (unlike a self-sealing fuel tank, which is not even close to the passenger). But the risk is very low.

The higher risk of cell phone usage is the same as anywhere else, people not paying attention and preventing others from communicating -- re-enter "mechanical" above, along with "electro-static" and other things. That's why on an airplane (at least here in the US) you're not allowed to use portable electronics below 10,000 feet. Why? Because that's the most common time a flight attendant will need to get your attention, for emergency or other situations. In-flight entertainment systems are allowed because their audio-video can be interrupted by flight personnel (let alone they immediately have your attention when they do ).

The genuine Pentax battery contains exactly the same standard cells as any other similar battery. You can buy the cells in reputable battery shops and replace them in a died battery - I know people who do this. In fact all these batteries for cameras and camcorders (and many other products) are manufactured in a few factories.

Of course you can! You can do all sorts of things too!

But is the "generic" resulted designed specifically for the real-time potential-current load of the K7/K5?! No. What will result?

As explained above. Reduced envelope where the load will get what it expects before voltage cut-off, a far greater frequency of variances from design, etc...

The thing with aftermarket / knockoff batteries is that many of them user cells that didn't quite passed QA in the factory - then you get those disappointing batteries that die very soon or give you pathetic results like only 1-200 shots with one charge.

Again, that's not the whole story. It's not just about "didn't pass QA," many do.

It's about using a battery pack that was not designed for the envelope of the end-design. If it was just about an output voltage, then I can and should go off and make a set of cheap "adapters" that give 3.6-3.7V, 7.2-7.4V, 10.8-11.1V and 14.4-14.8V outputs with "generic," Rechargeable CR-V3 batteries.

Got this email today from a friend who deals with batteries:

And let me explain his statements further ...

Hi Bob,
We've busted three common rechargeable battery myths that could save you a lot of headache...
Myth #1 - Batteries must be completely flat before you can charge them
While this is true of older battery technologies, lithium-ion/polymer batteries which are used in most cameras and laptops today can be charged at any time without any negative effects. There is no need to wait until the battery is flat to charge it.

In fact, completely draining Li-Ion can be a bad thing!

NiCD is notorious for "memory." NiMH is far better, but doesn't typically have the real-time current output of NiCD (2.5A+). NiCD is far better with depletion, as the potential is more consistent. I.e., when you recharge Nickel technologies, the potential (voltage) is actually how it detects if it is full or not. The "memory" issues arise when NiMH or, far more commonly, NiCD actually go to a "trickle" in potential, and the charger believes it is full, when it is actually not. Hence why one wants to drain NiMH and, almost always, NiCD almost completely, before charging.

Lithium Ion rechargeable designs, especially polymer (which is more staple, at a cost of longevity, although that is improvement), prefer to have a mid-charge when stored. The greater the capacitance in Li-Ion, the faster it degrades. At the same time, you don't want to deplete a Li-Ion and then store it, as the active, regulatory microelectronics still needs power. You don't want the cells dropping much below 3V potential

Care'n feeding of Li-Ion include the following:

- Keep your Li-Ion "topped off" when you use it or plan to use it -- do not store your Li-Ion batteries full charged for any mid-to-long-term duration, use them (say every week or two)

A week before a trip is a great idea. Feel free to top them off while on the trip as well. Unlike Nickel, there are no issues with Lithium being recharged from any, prior level of potential.

- When you plan on storing your Li-Ion, use them for about 60-80% of their charge -- i.e., just before, if you can estimate (e.g., number of shots), or just as it begins to drop in your device's indicator (nearing cut-off voltage of device, but still well above 3V)

It's safe to shoot and then leave your batteries uncharged for a month or two, as long as you yank them before they are fully depleted. On my K5, I yank them just before (estimate) or just as they hit the 2/3rds indicator, which means potential has dropped below best, nominal output (but still well above cut-off).

- Don't leave your Li-Ion battery in your device while it's plugged in as the norm -- i.e., having a Li-Ion battery that is constantly fully charged, whether it's in use or not, will reduce its life (yes, this is the same in the case of notebook computers)

If you're Li-Ion is constantly at max potential, it will degrade the fastest, regardless of whether it is used or not. That's why you don't want to just leave your power plugged into your camera with a battery any more than a notebook. I often yank my notebook's Li-Ion battery when at home, especially after a trip where it is half-depleted, and only put it back in before I travel.

Of course, in all cases, "planning" is not an exact science. When in doubt, weight the cost of a few months or a year reduced battery longevity to the fact of not having enough battery life.

Myth #2 - The cheap batteries on eBay have twice the power of the batteries in the shop
Not many consumers are aware that it is common practice in China for manufacturers to mislabel their batteries with higher capacities. The reason they say, is because that's what the market "wants". It doesn't matter to them that the batteries have only half the capacity mentioned on the label.
How do we know this? Because it even happened to us. Our own manufacturer started sending us batteries that were mislabeled. Thankfully we picked up on it pretty quickly and fixed the situation.
To fit more power into a battery the battery must be larger in size to fit the additional battery cells. Don't be fooled by a battery claiming to have twice the power that has no extra size for the additional cells needed.

By "power" you mean overall charge. "Power" is directly aking to real-time potential-current, and not "current-time" of the overall charge (and power-time when you factor in potential).

At the same time, you can still have a battery that is designed and can deliver a specific, real-time potential-charge over its life at a smaller, overall "charge rating" than a battery that wasn't designed for it.

That's what most people don't realize. They can't understand how a "smaller" battery from the OEM seemingly works "better" and lasts "longer" than a "larger" or "external" battery that has far more cells and "higher" rated "charge."

Again, real-time potential-current (real-time "power") has nothing to do with the overall, current-time (as corresponding power-time) that a battery is allegedly "rated" for. The "rating" can and is often done under a minimal load (like 100mA) instead of an actual, end-device load. The actual, end-device load varies -- except when designed for a specific unit.

Again, regarding "charge," why do Energizer Lithium batteries last longer, or work at all, compared to NiMH batteries, even when the latter does work? Current! (Energizer rates its Lithiums at 2.6A real-time current) And it's not just "potential," because even 1.5V Alkalines do not last, if they work at all, compared to 1.2V NiMH batteries for most devices, including smaller, compact cameras.

Myth #3 - Batteries deteriorate the more you use them
While technically true, more importantly for most people all batteries deteriorate with age REGARDLESS of how often you use them.
This means that from the minute a battery is made it begins to deteriorate slightly each and every day.
You will only notice the deterioration after 3-5 years when the battery will hardly hold any charge at all and need replacing.

Li-Ion, under continual use, will only last 1-2 years. Under infrequent use, even without proper care'n feeding, Li-Ion can last 3-5 years. For photographers, this should be typical, possibly 5+ years with proper care'n feeding.

Remember, rechargeable 3.7V Li-Ion cells != 3V LiMg (CR-V3) or 1.5V LiFe (Energizer Lithium). The latter will last for decades on the shelf, and will provide the same current until they are nearly depleted, and their longevity doesn't vary based on how often or little you use them. Li-Ion is completely different and it does matter how you charge and use them.

If you are a heavy user (we're talking professional photographer type user here) then the heavy use will also shorten the batteries life.

Like a typical notebook battery as well.

However for most people time will impact the batteries deterioration more than their use.
I thought it was worth a read.

I hope my taking the time to make all my comments above will be seen as the same.