Have you given thought to some kind of Battery Tender ?
I would go with a Solar Powered one that you could lay on the dashboard & just roll it or fold it up when it is time to drive somewhere
some of them can be plugged into your cigarette lighter or clamped directly to the battery itself
2009 Ram 1500 SLT QC, HEMI , 3.55 axle, Bushwacker flares, soft tonneau, Line_X, DEBO Step, Mag-Hytec, Weathertech mats
2016 Ram 3.0 diesel 3.55 w/LSD, G2 tonneau, Line-X, Weathertech mats, Mag-Hytec differential cover, Nfab bars, CB radio, Autonet wi-fi router, EGR bug deflector