TP-solar Solar Panel Kit 100 Watt 12 Volt Monocrystalline Off Grid System for Homes RV Boat + 20A 12V/24V Solar Charge Controller + 16ft Solar Cables + Z-Brackets for Mounting Amazon productlink to the kit you bought
Back to the original issue of the thread ... in a a dual battery setup, if the battery is isolated and circuit open, should be able to sit for a long time (at least a SNIP...econd battery when the vehicle is off and everything is supposedly “disconnected”. If you’re drawing a current that means you have a short somewhere, and if you need a CPAP finding that short will be far more valuable than all sorts of upgrades.
not a fun project, but my last rig pulled 80 mA at rest ... I chased shorts a ton but ultimately got it clean and she could sit for weeks on end.