Submitted by ckessel on January 10, 2011
I've hunted in the FAQs and articles, but I'm not sure I found an answer. I know the battery doesn't have a memory and 7 years is the replacement timeline if you pre-purchase the battery when you buy the car. What I'm trying to figure out is what actually governs the battery life? If I drive a relatively low amount, say 7500 miles a year, is the battery still going to need replacement at 7 years?
Or is it more dependent on how often you charge it? Is it better to top the battery off all the time or limit the charging to when it's necessary? My typical driving profile is maybe 20 miles a day, so I could easily not charge it all week, then charge it over night on a weekend as my standard procedure, only doing cop offs if I'm on the road frequently and for more extended periods (like on a vacation or a busy weekend).
So, I suppose, in short I'm trying to figure out how much the battery longevity depends on time versus use. My actual driving is often well less than 10k per year, so I'm wondering if it's better for me to NOT pre-purchase the 7-year battery swap.