#1Your battery is causing your engine to start slowly
Many batteries returned under warranty are just deeply discharged and work fine once they are properly recharged. If you notice your engine is starting slowly, the first thing you should do is check your battery voltage (it should be at least 12.6 volts) and charge your battery, if necessary. If you don’t have a voltmeter or a battery charger, you may want to get them, as they can save you a lot of money in the long run. If your engine is still starting slowly after charging your battery, have it checked (load-tested) at a quality auto parts retailer. Many will offer this service for free and this is the best method of determining if your battery needs to be replaced.
#2 Dim lights and/or electrical issues mean you need a better battery