BEC and Novak HV system

[Gee]

I had an HV esc burn up in the evo and replaced it with a MM and and extrenal BEC. It made a differnce in longer run time and also the LVC cutoff of Novak would start cutting out several minutes before the actual cutoff. It would also shut you down when you'd spike below the LVC. The batteries would still be above the LVC setting. I was wanting to put that BEC in my e-maxx that also has the HV 4.5 in it to see if the BEC is the reason or if it is the mm with the firmware/software upgrade that is making the differnece.
Just playing around to learn more about it. Like what makes the BEC different from a receiver pack? With a BEC you need to remove the red wire but a receiver pack you don't?