Car battery

I have a 1996 Nissan Sentra. I was out of town for a month and today when I tried to start my car, it did not. I opned the hood and found out that there was white acid powder on the battery. Does this mean that it is dead? Nothing in the car starts. Also, if it needs replacement, how much does a battery cost? The AAA person who came said it would cost me $123 with a 6 year warranty. Is this price too much.

P.S. I am very new driver who knows absolutely nothing (I am not joking) about cars

I find it a bit to expensive even for my area. I just bought a battery at Pep Boys for $88.00, and it has a warranty on it too. Shop around, I have always found that the AAA has always been a little pricey for me.

Car batteries last 4 to 6 years, on average. All lead-acid batteries emit acid vapor which eats at the battery posts and the battery cable terminals. Certain conditions can make the emissions of acid vapor worse. One is when the alternator charging voltage is too high.
When the battery post(s) gets corroded, they can be scraped (wire brushed, or sanded) clean. Then, the battery is good to go; unless, there’s another problem.
You may need another battery…under $50 from many stores. With, or without, a new battery, the alternator charging rate needs to be checked. If it too high, the alternator may have to be changed. Many auto parts stores will do this in the parking lot, in the car, for free. Just ask.

No, you need not automatically replace your battery. It does need a cleaning, however. Most of us do this job ourselves. It involves removing the attached cables, then scraping and washing the posts.

If you decide you really want another battery they can be had for around $50 at most auto parts stores, installation included. Top quality batteries may go for up to $90 but ordinary batteries are generally good enough for the average car owner.