I have been using the CM 9 and later 10 version of ROM.  I came across several posts about Siyah kernel giving better battery performance.

When Android 4.1.2 came out for MCM’s built, I thought I check it’s vsync performance and Siyah’s battery. The nightly ROM is 20 Dec 2012 with MCM’s version of Siyah 4.

23 Dec 12

23 Dec 12 overnight with MCM ROM and Siyah 4 kernel

Start 89%, end 63% or 26% for 8 hr 29min or 3.05%

27 Dec 12

27 Dec 12 overnight with MCM ROM and Siyah 4 kernel

26 Dec, 96% start and 71 % end. 25% for 7hr 6min or 3.5%

MCM ROM and Siyah 4 kernel

28 Dec overnight drain with WiFi and Google Now on.  100% on start, 85% at end.  Drain was 15% over 7h 9m or 2.1% per hr.