350D + BG-E3 + 100-400L kept switching off when used with AA batteries??

Had to swap over from Canon batteries to the AA battery pack which had near new alkaline (Duracell) batteries in it (I'm from UK). Switched camera on, battery life shown as full, but as soon as I pressed the shutter half way, the camera switched off with the battery life indicator showing empty.

Managed to buy some cheap new AA batteries, but same thing happened. Going to buy another two proper batteries now

I was using a 350D with BG-E3, and a 100-400L. I did try switching auto focus and image stabilisation off but it made no difference.

Is it a known problem when trying to use a large lens with AA batteries or is something wrong with my camera?

vtecsilver,

I use AA's as emergency batteries and yes, they can drain quite quickly, but not as fast as you report. Duracells are alkaline batteries, lithium-ion are better but less commonly available, which does sort of defeat the point of using AA's in the first place.

I also always make sure that my emergency supply is brand new. I use the partially drained ones in other, non urgent items like radios, wireless computer mouse etc.