maybe clean the battery terminals really,really good ?
I've had them 'look fine' but remove to see NOT fine....
This.
Checking your connections does NOT mean looking at them. It means taking them apart, and while you have them apart, you might as well clean them down to shiny bare metal and giving them a lick of dielectric grease to prevent future corrosion.
Cables can be bad and look just fine. Corrosion can be inside the jacket. How do you find that? Shake, twist, bend. IF there is corrosion in there, you can often feel it, and the rough treatment will break the cable completely. That's what you want - once it's completely broken, you know what needs to be replaced. It's no longer hiding from you.