traveling for a long period time? check this:

ECO-WORTHY Monocrystalline 12V Solar Panel, 25W +10A Challenge Controller, SAE Adjustable Mounting Bracket! Supports System Charging and Storage Connecting Cable, Car, RV, Boat, Shed, Disaster

Can wire the SAE cable inside the car, then it’s just plug and play. When you return to the US, plug it in. When you leave, disconnect and you’re good to drive — this is helpful to maintain the battery health. Letting the car battery die too much makes its lifetime a lot shorter