2007 Toyota Tarago Batteries failing

Hi, I have a tarago 2007 model that is now 6 yrs old, and has had 3 batteries and another being fitted tomorrow, they aren't lasting very long and I wonder if you can tell me why, I just had the car serviced recently and this wasn't picked up seriously annoying when your out with no phone. My other problem is a grinding noise when starting they car, mainly in the morning when the car is cold, I have been told it's the timing chain and it won't break? But the last two services this hasn't got better. Lastly the air conditioner rattles under the car when the car is hot? Any idea why.