On 21 Dec 2011 17:31:51 GMT, D. Dalton wrote:

I installed a new battery in my car just two years ago. That seems a bit
recent for a battery to give out...

Is there an easy way to determine which is giving problems: the battery or
the charging system?

If it's 2 years old it is probably still under warranty. I had one die on
me over the intensely cold spell at the end of 2009-2010 when the car was
iced up for 3 weeks solid. The battery shop checked my alternator was
putting out the correct voltage and when they saw that it was, replaced the
battery without any further questions.