Turn Signal problems of the 2010 Buick Lacrosse

While driving or sitting all the instrument panel/dash and headlight/daytime driving lights intermittently either flash off and on or shut off for several seconds and come back on. This problem has built up over time and the radio has also started to also intermittently turn off and on conjunction with all the lighting. This seems to occur when ever there is some kind of quick draw of electrical power, such as braking, downshifting of transmission to accelerate, turning on defrosters, or simply while driving. This power loss also affects the cruise control and when power loss occurs it will disengage. This disturbingly occurs while driving at night and power loss to instrument panel/dash and headlight leaves me in complete darkness for several moments at time. I have not idea how fast I'm going of if the road is still in front of me. I notice an issue with the previous body style of Lacrosse but not mine. If the battery is disconnected for several hours some thing or some program is reset and the issue will stop for roughly two weeks and then start back up, but so far the issue seems to intensify up restarting after the battery is disconnected. The drivetrain is not affected by the power loss and will continue to operate during the illumination and instrumentation loss. The issue does seem to repeat more frequently when in town with the constant acceleration and braking. On the interstate the issue will occurs intermittently while cruising and when accelerating or braking and if some device is activated such as defrosters, turn signals, or air conditioning. With the intermittent and so far short nature of the power loss, I'm not able to ascertain if any other systems are being affected as of yet. The problem resembles alternator or battery failure, but both were replaced at the onset over a year ago. Videos of the cluster are available but too large to attach.