I own a Nikon Coolpix L18, it is currently set to 8 MP. I want to minimize the file size, where can I find this in the camaera settings?

Regardless of the size of the memory card, the largest video file you can create on the L18 is 2GB. You can stop recording one clip and then record another and another, and then combine them on a computer to create longer clips.
In a Hollywood movie, you seldom see individual scenes as long as five minutes in length. They're usually put together from much shorter clips, changing viewpoints and camera angles.

You can download the current versions of all (free) Nikon software here.

Press the shooting mode button in shooting mode to display the shooting mode selection menu and set the shooting mode to Auto (the green camera). Press MENU to display the shooting menu. Navigate to "Image Mode" if necessary and press OK. Take your pick of sizes here, then press OK to save the change and then MENU to exit the menu.

http://support.nikontech.com/app/answers/detail/a_id/61

You can download the current versions of Nikon software from http://support.nikontech.com/app/answers/detail/a_id/61

Go into the Shooting Menu, select Image Mode, and select the desired image size/quality. If you want to go all the way, select 640 for 640x480 resolution (0.3 mp).

Be aware that if you do so, the pictures won't be usable for much more than email. You're certainly not going to make 4x6 prints from them. You may as well be using your cell phone, if it has a camera, instead of a 10 mp camera.

You can download the current versions of all (free) Nikon software from here.

Press the menu button and go into the image mode setting. Use the right arrow to go into the table of quality options. Use the up/down on the dial to select the file size (quality) you want. You will then see the quantity of images the card has room for, at the selected resolution.

I had the same problem, but I went to Lithium batteries..I received my camera for Christmas, got the batteries day after and have not had to change them as of yet.

make sure you have either lithium AA batteries or Alkaine AA batteries it happened to me before too and this worked