The battery issue which some people have had may be the wireless sleep policy. You probably all rember this, but I'd forgottton until I installed a replacement image file which set up from scratch
In order not to get SOD, we had to change the WiFi sleep policy to 'Never' i.e. still on when the Vox is sleeping.
If the battery is draining overnight in sleep mode, it may be worth checking your settings. It's been dealt with elsewhere, but for ease:
Settings>Wireless & Networks>Wi-Fi settings
Press the menu touch-button and select 'Advanced'
Select Wi-Fi sleep policy and select 'When screen turns off' rather than 'Never'.