Originally posted by moshepupkin I found that it is SOMEHOW related to the batteries. Rechargeable batteries, even fully charged good ones, often cause problems. Alkaline batteries also cause problems, but slightly less often. I understand that power is important for AF, but I am not sure that not being able to use rechargeable batteries at all and being able to use alkaline ones ONLY if they are absolutely new, bought from reliable retailer and only then they last for a bout 100 shots...
Forgot to mention: I stopped using rechargeable batteries ( I use them for flash only now), I tried THREE different NEW alkaline batteries until I found these that did not cause AF problems...
There is a lot of variability between rechargeable battery brands. Also, like any other battery, the more often a rechargeable battery is recharged, the less capacity it has. So age has a lot to do with it.
If you look at the many threads in this Forum about AA batteries, you will see one trend over and over - use Sanyo eneloop batteries if you wish to use rechargable batteries, or use non-rechargeable lithium batteries. As also explained in other threads, the issue isn't just total capacity but also how much peak energy a battery can provide. Digital SLR cameras need a lot of energy at the moment of exposure. Many alkaline batteries cannot provide this level of discharge for more than a few shots.