We know the payment types we have designated in our wallet, have a default, as well as an arbitrary number of back ups. But let's assume you forgot your payment for your default card. You're at the supercharger and the charger is inoperative. So you use, or select should I say, one of your back up forms of payment. That will not do you any good. The form of payment that governs your ability to supercharge is found under charging in your app. If that happens to be the one that you forgot the payment for, you're SOL. You need to designate one of your other payment options. I've gone to 4 1/2 years without knowing this until last weekend.