My car is having some strange symptoms and I hope you can help diagnose it. This morning the car wouldn't turn over and it needed a jump. After that it drove fine.
This evening I cleaned the terminals and battery posts. The first time I tried to start the car just cranked for a couple seconds. The second time it started up. I took it for a test drive, and several times after driving 35+ mph the engine died as I was coming to a stop. Several more times the engine almost died, but caught and stayed running.
I have a 2008 Impreza which still has its original battery (4.5 years old), so I suspect it's a bad battery. However, these aren't the symptoms I've seen for a dying battery in the past.