> My current v-mount setup gives me weird voltage warnings when the fan kicks in... Ouch, that Arizona heat is gonna make your fan work overtime, which is definitely why your voltage is dipping. In my experience, the Sigma fp is super sensitive to anything that isnt a rock-solid 8.4V. If your dummy battery is just a direct cable without a real regulator, that fan power surge is gonna trip the camera every single time. Honestly, those cheap dummy batteries are a huge gamble. After trying many setups over the last two years, the only thing that stopped those warnings for me was switching to the Zitay Sigma fp DMW-DCC11 Dummy Battery to D-Tap. It has a proper built-in voltage regulator that handles the spikes way better than the generic ones. It basically filters the power coming from the big battery so the camera stays happy even when it gets hot and the fan ramps up to max. For the desert, you also want a battery that wont overheat itself. Going with something like the FXLION Nano Two 98Wh V-Mount Battery is usually better because it stays pretty cool and the little OLED screen is a lifesaver for checking your remaining juice under the sun. If you keep seeing errors, check your v-mount plate too. Sometimes the wiring in those cheap ones is just too thin. Switching to the SmallRig V-Mount Battery Plate with Crab-Shaped Clamp 2988 fixed a lot of my weird flickering issues. Good luck in the desert!