So, had my 2011 LR4 for 8 months and have had to jump start it 3 times. First two were from having the radio on for 15 mins with engine off. I assumed the auto radio switch off due to low battery was a sign that battery or alternator were bad. Seems this is normal though. Yesterday was doing the front brakes. Opened and closed doors several times and battery flat! Got the battery tested and appears fine. Other posts here indicate that battery can still be culprit even if output amps, voltage is within spec? Batteries only last 4 yrs?????? Might replace anyway. Any definitive tests for diagnosing bad battery or alternator?