How long is the fucking car battery SUPPOSED to last?

Haha. Where it die?

In the trunk.

So do you have anything charging it? I dunno what the stock altenator in your car will produce.. You may need to get a bigger one, or a second one.

I dunno, I didn't installed it. I just went to Kragen and was like "Gimme the biggest, baddest mothafucker on the shelf". Then I took it to the audio place to install it (took like 2-3 days), and I asked the guy over there how long the battery would last and he said I should recharge it/buy a new one right then. What I don't get is what could've made it fuck up so quick.

It's supposed to charge as you drive. Gasoline energy is converted to electrical energy.

Really??? Even the ones that are for the system only? Becuase my fuel arrow is almost buy the E....hmmm..

ThNAKX!

What he meant was that it could go for 1-2 years before needing to be replaced. It just needs to be recharged. The batteries that come in your car are hooked up with some thing called the alternator, which takes some of the energy coming from your engine and uses it to recharge your battery as you drive. Because the new battery is just sitting there, it isn't being recharged, and so it ran out of juice. It still works, it just needs to be recharged. I would inquire about a secondary or larger alternator to try and charge both batteries while you drive.