[Q] ROM with the best battery life?

Exactly what the title says. I've been looking here and there for some ROMs that I would like to flash and I found quite a number of them to try out. However I want to hear from the experts who have been flashing custom ROMs all the time. What would you say would be the best ROM on battery life? I am currently running Hyperdrive RLS21 and I'll say it does decent on the battery life albeit the standby time can improve (I lose around 10% in a night if I leave it 100% uncharged).