If the MacBook Pro 13 is old you’ll probably have to get a new one. Or you can replace the battery again or get a professional computer fixer. If these don’t work you’ll probably have to get a new one.
If your car USB port isn't charging your phone, the problem could be with the port, the cable, or even the phone. Not all car USB ports are designed to charge phones, or power peripheral devices at all, so there's a chance that you're dealing with that type of situation.