sir,my canon a570 is not showing a good performance with the batteries.

we are using alkaline,ordinary batteries(EverReady,Nippon)which are not rechargeable.we also used some rechargeable batteries like Sony,Panasonic which are 2500mah and 3600mah but we are not able to take more than 5-10pics.so please suggest us regarding the batteries which can give more pics.

That doesn't sound right. Have you tried resetting the camera? You need an Mah over 2000 for cameras these days and rechargeables are a great idea. You may want to try duracells. I get a LOT of time out of them.

My experience with the A570is is that battery life is below par. I often get the battery low sign after only 35-40 shots, using freshly charged NiMH 2500mAh batteries. I think this camera is much more power hungry than advertised.

I now carry a spare set of rechargeable batteries and an emergency set of Lithium Energiser batteries. The rechargeable batteries are exhausted first and then the Lithium set fitted if required. Lithium batteries are expensive and not rechargeable but have very high power capacity and also have a rated 10 yr. shelf life. This makes them ideal for use in an emergency. Don't even bother with alkaline batteries - even top brands like Duracell and Energiser will not have enough power capacity for this power hungry camera.

This is less than ideal but one learns to live with it. I have a large non-Canon camera case that fits the camera with the spare batteries and a spare memory card. Also, when the low battery sign comes on, you can turn off the LCD screen and use the viewfinder to conserve power. I often get another 30-40 shots after the low bat. sign comes on.

I think you're onto something there, Jinmo. I've heard of this from time to time and I believe that it may be a batch of cameras which for whatever reason, eat up batteries. Have you checked for a firmware update that addresses the issue? I'd also contact Canon about an RMA return. Because clearly this is a faulty camera that needs to be replaced.

My conclusion; The batteries are the problem.

The cause is the high internal resistance of the used batteries!

Many NiMh batteries have a high internal resistance for use in the A720.
The same applies to the alkaline battery, including those of Duracell.
The Electo 2300 mAh NiMh batteries that I had used, have an internal resistance of 500 mOhm!
The NiCad's Sanyo 700 mAh give no problems.
NiCad's have a much lower internal resistance than NiMh batteries.

The internal resistance can be determined by measuring the battery voltage with load and without load.
For the load I used a resistance of 1 ohm.
Discharge current is then about 1 A.

Example.
Without load 1.3 V voltage measured.
With load of 1 Ohm a voltage of 1.2 V measured.
The internal resistance is approximately the voltage difference measured in ohms.
The internal resistance = 1.3 - 1.2 = 0.1 ohms.

As far as I can see Sanyo NiMh batteries and in particular the Eneloop AA 2000 mAh, are a good choice.