Three weeks while going through three cards, thats not bad at all. The electrical view finder (EVF) will eat a lot of the batteries life, if you really want to prolong the batteries use then turn off the EVf and use the optical view finder. THis will be something you will get use to when you get the D80, it does not have the option of the EVF, actually only two DSLRs have the ability to use EVF: Olympus E330 and the Panasonic Lumix DMC-L1

There is a measurement for rechargable batteries.
"mAh" - milliampere-hour.

From wikipedia:
The amount of time a battery will last can be calculated like this:
t=C/I
t is the discharge time in hours, C is the battery's current capacity rating, and I is the current draw from the battery. If the batteries are connected in parallel, then multiply the capacity rating by the number of cells.

For example, a CD player draws a constant current of 200mA from a 2300 mAh rechargeable battery consisting of two AA cells connected in series for a total rated voltage of 3V. So, 2.300Ah / 0.200A = approximately 11.5 Hours of battery life. Remember that most electronic devices stop functioning when the battery voltage drops below a certain voltage, so the actual battery life will be less than calculated.

The actual time will be much less than calculated because this assumes that the battery voltage remains constant, which it does not, so it's only a rough approximate. Furthermore, battery capacity is dependent on discharge time and thus should be given with a stated discharge time

Have fun.

Joe

Hey thanks Joe. That makes a lot of sense. I did open the chamber the the batteries were the older ones I had around here that were Duracell not Energizer Lithium.

Okay I need to get, I just went by the business adn there are bushes covered in snow with the lights glowing under all the snow! It looks too cool to not run back over there and get a few shots...

Have a great night!

Digital cameras do 'eat' batteries, but the Canon products seem to do better than the average. One way to entend battery life is to reduce the drain. Two items I've found helpful are:
1. Turn off the big LCD display and use only the electronic view finder (EVF).

2. Set the auto-focus to be active only when the shutter button is pressed half-way down (to the first detent).

I can't assess whether you took a lot of exposures or not since you left out that information. You stated it was about 3 cards of images. This tells nothing since the cards are availble in a wide range of sizes. For example, I have the Canon S2-IS and I equipped it with a SD memory card having 1 gigabyte of capacity. It took several hundred images and many sets of recharged batteries to fill that card!

And yes, it does take battery power to transfer images to your computer or other device. Here, time is the factor and all displays on the camera should be turned off to conserve power.

However, may I suggest a better option for image transfer if your memory card is removeable. If your printer has memory card slots, use these. The other option is to install a card reader to a USB port on your computer. These readers are not expensive and do a credible job of copying images from the card to a hard drive or CD-ROM. I recommend using an USB2 port, not the orignal, slow, SB1 port.

When the card is inserted into a card reader, it will map to your computer as another data drive, so be careful. it's a two way street - The card be written to as well as read. My advice is to NEVER do an operation that "writes" to the card as this may upset its file structure. Most cameras use a proprietary format and you could mess that up with a "write" or "save" to the card. A 'delete' may be OK, but for safety, I don't recommend it. Put the card back into the camera for deletions.

In a card reader, you can copy files from the card to a hard drive, floppy, or CDROM in the same fashion as any other file transfer. (The floppy won't hold many images.)

Using a card reader eliminates the hazard and bother of a set of batteries going flat in the middle of a file transfer, and it is much faster in many cases.

Rechageable batteries loose charge at an alarmng rate. Nickel-metal-hydride batteries may loose 8% per week or more, thus if these have been sitting around for awhile, you should recharge these before going out on a photo-shoot. For example, if the batteries have been sitting for 3 weeks, the amount of retained charge is estinated as 0.92 x 0.92 x 0.92 or 78 precent.

Lithiun-ion batteries are better, but they also loose charge, but at a lower rate.

I keep spare sets on charged batteries in my photo bagm and if I'm going on trip, I'll have one new, unused, uncharged set as well. I also carry means to recharge these batteries from both the car and conventinal wall sockets.

Good morning..

Joe covered the EVf in his post. Good info.

Funny about the card size because last night around 11 while I was working I realized I did not put the size of my card in my post - DUH ...Please forgive my error! LOL
The problem is probably more my brain then the camera.

If you read my reply to Joe I posted I did not have the new batteries in the camera. They were ones I have had for a very long time. That was the problem. The shutting off of the EVF will help alot. I've had this camera for over a year and this is the first time this has happened so that is why it was so surprising when it went dead so fast.
My computer also is new - bought both at the same time and have both functions you talked about. I usually use the USB2.
Thanks and have a great day

the original rechargable battery is done.so i put in 2 cheap double a batterys the camera wont boot up.i take it to a camera shop they put in expensive alkaline double a batterys and low and behold it worked.i tested both sets of batterys mine and the camera shops and both around 1.6 volts.i was going to throw the camera away and now it works.why did these batterys work and mine did not.info appreciated

Quote, "actually only two DSLRs have the ability to use EVF: Olympus E330 and the Panasonic Lumix DMC-L1"

Actually that is not true..The Pentax K-7, K200d and K-x all feature live view.

I have been shooting a Pentax *ist DL (6.1mp) and have just ordered a Pentax K200d to get the "shake reduction", "Live View" and 14.6mp resolution while still allowing me to use all the Pentax lenses that I currently own, going back to the old Pentax screw mount lenses from the late 60's.

Now for the original question regarding battery life:

Now in regards to the original question regarding battery life:

First off, you cannot judge battery life by how many SD cards you have recorded because the number of images you can put on an SD card is dependent upon both the size of the card and what format you are shooting.

My Pentax *ist DL will allow me to use a maximum 2gb SD card. With a 2gb card I can record 165 images in RAW format (6mp), 760 in JPEG "Best" mode (4mp), and nearly 2400 images in JPEG "good" mode (1.5mp).

Now in regards to the original question about battery life. There are a number of factors that effect battery life.

First off, per the table in my Pentax 8ist user manual battery life varies greatly depending upon what type of batteries you are using.

Obviously the best battery life is with the special batteries that are made specific to this camera, but the Pentax 8ist will also allow me to use 4 AA batteries so I will only show the comparison of AA batteries.

Approximate image storage and playback capacity:

AA LITHIUM ION- batteries: (Note that operating temp has a big effect)

23 DegC normal mode 750 images, 50% flash 650, 100% flash 550-Playback 700minutes

0 degC normal mode 670, 50% flash 570, 100% flash 470-playback 470min.

AA Rechargeable NiMH 2500mAh
@ 23degC 560, with 50% flash 500, 100% flash 440, Playback 470
0 degC 500, with 50% flash 440 and 100% flash 380, playback 400

AA Alkaline batteries:
23 degC 90, with 50% flash 70, with 100% flash 50, playback 140

Not recommended at 0DegC.

.................................................

I primarily shoot nature and wildlife photography and I am looking forward to the live view feature because I often shoot macro and very low angles, often requiring the camera to sit right on the ground. Currently I am using a right angle view finder but the live view will make it much easier.

On average I shoot about 500 pictures a day and have shot as many as 1500 in one day. When I go in the field I carry 10 2gb SD cards and 5 sets of AA NiMh (2900mAh) rechargeable batteries. While the above table for NiMh rechargeables was for 2500mAh batteries from my experience I find that the 2900mAh batteries perform as well as the Lithium Ion batteries.

You can expect to pay about $20 for a set of four AA Energyzer or Duracell 2900mAh batteries and another $20 for wall charger but after having recharged them perhaps as many as a hundred times I find they are a bargain at twice that price. I also bought some generic rechargeable NiMh batteries on Ebay. The ones listed as 2900mAh work fine, but the ones listed as 2500mAh do not perform nearly as well, although they do work well in my external flash equipment and flashlights.

When buying rechargeable NiMh batteries be very careful to check the amp/hour rating. They make some AA NiMh batteries that are listed as rechargeable garden light batteries. They are only 1800mAh and while they work fine in those little solar powered garden & walkway lights, they are useless for photo applications.

I have already commented on the auto-focus feature in a prior posting.

I see that you are using lithium ion batteries. These are the best rechargeables available to date. If you have equipemnt that uses NiMH (Nickel Metal-Hydride) cells, these are poor seconds compared to the lithium-ion calls. A NiMH cell will loose 10% charge per week and sometimes more. However, last year I tried the new Hybrid NiMH cells and found these to be a great improvement. These cost almost twice as much as the regular NiMH, but are worth it. I found my set at Batteries Plus. Since then, I have been replacing all my old style cells with these improved ones. When I go on a field trip, I will have a freshly charged set in the camera and 2 to 3 more sets of freshly charged cells in the bag.

The extra cells should be protected from shorting, and the packaging must be convenient to open and take little space. For short time use, the box that held a 4-pack of cells will suffice until it starts to wear. A source for small, inexpensive, compartmented plastic boxes can be found at places stocking fly fishing gear or office supply stores.