Initially, I set up a second battery in my '95 4WD Suburban with a Redarc BCDC 1225D unit. Due to space limitations, I was only able to squeeze in a 72Ah battery under the hood. Since then, my project has morphed (grown) and I plan to construct a battery/component box to mount where a second row seat currently is. Plan is to go with 2x100W panels and a 100Ah SOK battery. Since I already have the Redarc, would it better to just stick with that or swap it out for the Renogy DCDC? How does a DCDC device (Redarc or Renogy) perform when it comes to functioning as an MPPT versus a standalone MPPT?