I have a 2004 Toyota Rav4 with 150K miles. I bought a new battery about a month ago, but the "check battery" light has been turning off and on periodically. It turns on at various times: when I start the car, when driving, etc. It usually turns off within a minute or so. Sometimes it'll go a day or two without turning on. I had battery and alternator tested at autozone and both are fine. I changed the terminal clamp because it was rusted, but the light still turned on. One theory is the valve cover gasket is leaking oil, and that could be causing the problem. Toyota said the alternator is slowly dying (it's about 5 years old, remanufactured). Any suggestions?