[Q] SD card causing battery drain?

Ever since I've been using the 4.1.2 stock ROMS I've noticed my battery has been draining REALLY quickly. I've been using JuiceDefender and it wasn't helping.

I recently installed GOPowerMaster and checked the Consumption tab. It said 64% was being taken by something called 'Security Storage'. As I'd been getting random notifications saying there was an error with the SD card I took the SD card out and ever since my battery has been fine.

Any idea what's going on here?

Cheers,
Chris