Lights

Which light are you using exactly. The hours and lumens sound good and I'm gradually changing my thinking about battery packs.

I commute out in the sticks as well. But unfortunately bits still go missing from bikes in the rack. If tools are required to remove your OK but lights, computers etc no chance. Wouldn't even leave my bottle on the bike.

I use a six pack, and I have the bracket on the bars fixed with a accuscrew security bolt (from here, think about making the whole bike tamper proof!)
http://www.accuscrews.co.uk/67-security-button-head-screws