I found a source for a battery holder that will carry 10 AA batteries. It is fairly sturdy. The company is Thomas Distributing. Their site is http://www.thomasdistributing.com
or you can reach them at 800-821-2769. The item number is MS-BH-10-AA. Price is $2.30. When you place your order, you specify what type of connector you want. I chose a 9V-style snap connector. This works great with the "hard cap" 9V connectors you can buy at any Radio Shack (see picture). I use Lenmar 2700 mHh rechargables bought at Frye's (but the labels shrink/come off). This will give you 12+ volts.