More than likely, yes. Use an inexpensive digital voltmeter to measure battery voltage while the engine is running. It must be between 13.75 and 14.75 volts. If it is low, suspect the generator. GM has had a very poor design since the 1987 model year. It is very common to go through four to six of them in the life of the vehicle. What many professionals are finding out is to reduce the repeat failures, replace the perfectly good battery at the same time. It will work fine in older cars but as they age they lose their ability to absorb the many huge voltage spikes produced by these generators.