Camera Batteries

zej

What's the difference between AA batteries and a rechargable battery in cameras?

youllneverknow

they can hold a charge for longer

zej

And would you say AA batteries are "bad" like?

youllneverknow

i hate AA batteries...my normal digital camera eats them up i could possible use it for an hour then they die..my bridge camera has its own li-ion rechargeable battery that coan last up to about 3 to 6 hours fully charged

emanresu

Both types are good. It just depends on what the particular camera uses.

Most models now seem to use the Lithium Ion type batteries than the Rechargeable AA type. You could usually manage with just the one Li-Ion battery supplied with the camera as they last a long time after charging, but if necessary you could buy a spare.

Li-Ion batteries last longer after a charge than a set of rechargeable AA batteries. But you can easily have as many spare AA batteries as you want charged and ready to use. You can buy a spare Li-Ion battery but they are more expensive, and not as readily available as AA's.

In fact, if you are using a camera with AA batteries, and they go dead when you have no spare set ready, you can even use non-rechargable AA batteries if there is something important you need to photograph. But non-rechargables wouldn't last long in a camera, and would be totally impractical for ordinary use.
However, if you are using a camera with Li-Ion batteries, and the battery runs out while you are away from home, and you have no spare charged battery ready to use, and you have no access to an electric socket, then you cannot take any pictures until you have a chance to charge your battery again.

emanresu

I didn't see post number 4 above until after I posted mine. I used to use rechargeable AA's and found them fine, but I always needed to have several spare sets charged and ready to use. Now I use the Li-Ion type and I actually prefer it (but I still need to have a spare one ready, although one Li-Ion would be enough for many people).

hbr

zej wrote: »

What's the difference between AA batteries and a rechargable battery in cameras?

AA is a size rather than a battery type. Some AA cells are rechargeable,
some are not. Rechargeable batteries are usually NiMH or Li-ion. These
are better in the sense that you can recharge them many times.

Heebie

AA rechargeables are actually lower voltage than their non-rechargeable counterparts.. so some equipment will function differently when being used with NiCD or NiMH AA's. (NiCD's are WAY not what want.. they don't hold nearly enough current. NiMH's are much better for that.)

For some reason, no-one seems to have ever bothered making an L-ion battery to replace a AA.. probably has something to do with the voltage output of an individual cell within the battery or something along those lines.

When looking for rechargeable batteries, you want to pay attention to the mAH rating.. that's milli-amp-hours. The higher this number, the longer the battery will last at s single charge. I have seen upt o 3200mAH AA's. (How long they last will depend on your camera equipment, how often you use them, and whether you properly follow the charging regime for the batteries.)

NiCD batteries should always be fully discharged until they are dead before they get recharged.. NiMH batteries should actually be recharged before they die. L-ion batteries seem to vary by manufacturer.

Lead-acid AA's (often called "general purpose" etc.. ) shouldn't be used in this kind of kit AT ALL. A set of lead-acid AA's will die in a digital camera in literally a matter of seconds or maybe a minute or two.

Alkalines generally last anywhere from 10-15 minute of use, up to an hour or two of use in the camera.

Lithium (not L-ion.. and not rechargeable) batteries will last a good long time in a flash, and longer in a camera than any rechargeables... but still not all that long..and they're very expensive.

NiCD's somehwere in between lead-acid and alkalines.

NiMH's somewhere between alkalines and lithiums.

I hope this is useful to you.

NakedDex

I have no idea where you came up with those times but I'm pretty sure they can all be discounted on the basis of them being arbitrary alone. Asking how long a battery will last in a camera is akin to asking how long a piece of string is.

The difference between "AA" cells and battery packs is size. The difference between cell chemistries, however, is vast.
NiCd cells are 1.2v, as are NiMH. This voltage difference between these and standard alkaline batteries (1.5v) is what causes them to seem to die quicker in camera equipment, due it's high drain nature.
That voltage is the nominal voltage. A fully charged NiCd or NiMH is about 1.6v, where a fully charged alkaline cell, is about 1.8v. A fully drained alkaline cell gives a reading of around 1.1/1.2v, where a drained NiCd or NiMH is around .9v.
Essentially what this means is, despite your battery capacity possibly being higher (you can get AA cells in very high current capacities if you're willing to pay), your operational voltage range that is of use is lower in camera gear, as said camera gear is designed to operate to a battery meter which will shut down the body/flash once it reads below a set value (usually around 1.2v).
The problem with that value is that it's only the half-charge point on a NiCd or NiMH cell, so your battery still has a charge, but not one that you can use.

The reason Lithium packs are used is because lithium cells have a better discharge pattern while in use. They'll provide more power, faster and survive better under the high-drain, high intensity use that cameras require power for. Operating a mirror motor, shutter motor, focus motor, VR/IS/OS motor all at once and all very suddenly is a lot to ask of such a small battery pack. This is where lithium packs come into play in a wide variety of uses. It's also why lithium is seeing a serious upsurge in use for cordless power tools.



The basics of it is, AA cells will work, but not for as long. Lithium packs are design for high drain devices, and that's why they're recommended for photography.

magicbastarder

my dad's old fujifilm digital (never got my head around that one) camera has a battery drain option; rather than taking batteries which are half drained out of the camera and charging them, you can get the camera to drain them fully. takes about an hour.

Heebie

Those times were based on direct personal observation over the course of about 8 years that I worked in camera shops and photo labs... they are far from arbitrary, and I stand by them.

As for my having said, "AA rechargeables are actually lower voltage than their non-rechargeable counterparts.. so some equipment will function differently when being used with NiCD or NiMH AA's. (NiCD's are WAY not what you want.. they don't hold nearly enough current. NiMH's are much better for that.)".. my explanation of that is bang on (albeit simplified).. and you repeated it using a lot more words.. and some numbers thrown in. Some of the extra detail was useful in deciding what kind(s) of batteries to consider.. much of it was not.

You also neglect to mention the mAH (technically: gravimetric capacity) rating at all.. and that is what dictates how much current the battery will put out before it is dead. (meaning.. before it's voltage drops below it's rated nominal level.) mAH's is the rating of how much current can be drawn from the battery. If you have a 1200mAH battery.. you an draw 1200 milli-amps for an hour before it's dead. If you're drawing 1800 milli-amps.. it'll die in 45 minutes.. if you're only drawing 600.. it'll take 2 hours to kill it. (all from a full charge.)
If you instead by a 3200mAH battery.. a 1200mA draw will take 2 hours and 40 minutes to drain the battery.. and a 600mA draw will take 5 hours and 20 minutes. (again from a full charge.)

The only reason to mention voltage at all.. is that V=IR [Voltage (V) = current (I) times resistance (R).. so if you decrease the voltage (V).. the current (I) and resistance (R) are also affected. If you change the current draw.. the battery life also changes.. and things like motors spin at different speeds. (depending on their design and control mechanisms.)

NakedDex wrote: »

I have no idea where you came up with those times but I'm pretty sure they can all be discounted on the basis of them being arbitrary alone. Asking how long a battery will last in a camera is akin to asking how long a piece of string is.

The difference between "AA" cells and battery packs is size. The difference between cell chemistries, however, is vast.
NiCd cells are 1.2v, as are NiMH. This voltage difference between these and standard alkaline batteries (1.5v) is what causes them to seem to die quicker in camera equipment, due it's high drain nature.
That voltage is the nominal voltage. A fully charged NiCd or NiMH is about 1.6v, where a fully charged alkaline cell, is about 1.8v. A fully drained alkaline cell gives a reading of around 1.1/1.2v, where a drained NiCd or NiMH is around .9v.
Essentially what this means is, despite your battery capacity possibly being higher (you can get AA cells in very high current capacities if you're willing to pay), your operational voltage range that is of use is lower in camera gear, as said camera gear is designed to operate to a battery meter which will shut down the body/flash once it reads below a set value (usually around 1.2v).
The problem with that value is that it's only the half-charge point on a NiCd or NiMH cell, so your battery still has a charge, but not one that you can use.

The reason Lithium packs are used is because lithium cells have a better discharge pattern while in use. They'll provide more power, faster and survive better under the high-drain, high intensity use that cameras require power for. Operating a mirror motor, shutter motor, focus motor, VR/IS/OS motor all at once and all very suddenly is a lot to ask of such a small battery pack. This is where lithium packs come into play in a wide variety of uses. It's also why lithium is seeing a serious upsurge in use for cordless power tools.



The basics of it is, AA cells will work, but not for as long. Lithium packs are design for high drain devices, and that's why they're recommended for photography.

As to this last section...that's fine & dandy.. but if your camera takes AA's.. you have the choice of buying lithium AA's at ~€10 or so per set of TWO (and many cameras take four) and being able to shoot on a full set of those batteries for a fairly short time (a matter of hours of actual use, especially in a bridge camera where turning the camera on or off generally causes a lot of motor-driven action, and a display is always being updated & backlit.) or you can be more economical and spend the cost of 2-3 sets of Lithiums and get some high mAH-rated NiMH batteries instead.
(If you could get Lithium-ION based rechargeable AA's.. then that's absolutely would be the way to go.)

As for magicbastarder's mention of the battery drain function... there are actually little doohickeys you can buy that are just designed to drain batteries. (they're generally a resistor-pack and an LED.. the resistors keep the battery from having a complete short-circuit on it.. and the LED tells you when there's no longer enough current to run an LED.. and since it takes very little to run an LED.. that's pretty much dead.. real dead.)
I think they're usually called "battery conditioners" or something like that.. and they do make a big difference in battery life over the long term.. but you do have to remember to use them. Generally NOT a good idea on Li-ion batteries though.. Li-ion batteries to NOT like to be discharged fully. (They actually have little devices in them that permanently kill the battery if the charge drops below a certain level.. because charging them from a state below that is likely to cause an explosion.)

NakedDex

I refer to power law, not ohms law. Hence the inclusion of voltage rather than resistance. I find it more useful in working out practical, rather than theoretical, lifespans of cells under various drain rates. Though, I'll grant you, aeronautic electronics (my background of the last seven years) doesn't tend to rely on batteries very often. The other reason for this is that a cameras battery meter is, essentially, a voltmeter. If it were an ammeter, this point would be moot. At a set voltage, the camera will refuse to operate, regardless of how much current is still available.
With regard to omitting the explanation of current rating, I didn't feel it necessary to re-hash what you had already explained.


I do concede that I wasn't taking bridge/P&S cameras into account, however, it should be noted that thse platforms (to the best of my knowledge) don't have the same constraints for voltage on their "auto shut down" for low battery. Also, many of the P&S and bridge cameras are now coming with small lithium-ion and lithium polymer packs these days, for both size and increased life reasons.
To those who still use AA cells, I regret my oversight. Lithium cells are the best performers, high-power NiMH make an adequate substitute.

My post was simply to expand on the difference between each cell type, not to cause affront to your post.