What causes more power usage for Plus and Pro versus original A129 Duo?

[ViofoCanadaUser123]

I am using the original A129 Duo with a BBMYC Bi-750. The battery runtime duration test results from BBMYC show that the Plus Duo and Pro Duo models run 10 hours less compared to the A129 Duo original. What is causing the extra power draw? Is the the 4k and 2k or is it more that the rear camera has its own processor? The original A129 Duo has only 1 processor, located on the Front camera.