Battery Question

[BizZill211]

I'm new to the Tahoe family. I just got a 2003 I think Z71, no bose or onstar. Around 173k on the dash, but everything runs great. I fact I love this gas guzzler lol. Well a few nights ago I was waiting for my wife to get off work with the truck off listening to the radio for about 30-45 min (because she got off late) and the truck died on me. I was lucky enough to find someone with some jumper cables to get me back going. I took the battery to get tested and everything was good.

So my question is, Is that normal for the battery to drain that much just from listening to the radio in that amount of time? I use to sit in my Old's Intrigue for up to 2 hrs waiting and never had that problem?

 

[MrBalll]

I found it to be that quick, yes.

 

[The 'ER]

How old is the battery?

 

[BizZill211]

How old is the battery?

for some reason it's not marked. So I'm not too sure. I just wanted to see if it's normal for it to drain like that before I buy a new battery and have the same problem

 

[The 'ER]

I run my radio every morning before work in MN and I run 30 minutes no problem. See if the local auto parts store has a tester to see if it tests good or not. We have one at work which I used on my Mustang to find out the battery was junk.

 

[chauncey0337]

I've gone an hour easily but I turned my sub off when the engine wasn't running.

 

[M3PO]

Batteries have different amounts of storage, I think they are rated in Amp Hours, so your battery could be "good", but small in storage. Think of like your truck having a 5 gallon fuel tank, it will start and drive just fine, but needs to be refiled often.
I was waxing my truck this last summer and the battery pooped out after aprox 30 minutes, if that. The dealer put a new battery in when I bought it. After looking at the battery, it was the wrong size for the truck, capacity and footprint wise. I bought a good/the right battery with plenty of storage and I can leave the stereo on, mobile phones charging, etc for a while (never timed it, but more than 30 min).
If you look at Autozone or another site, you can see on the battery specs "reserve capacity minutes".
Hopefully this makes sense, I am not a tech or an electrical guy, but in the end there is capacity ratings to batteries.

 

[domin8]

You are correct. This has to do with the reserve rating for the battery. Additionally, another factor has to do with the cca and ca ratings. For example, if a vehicle requires a rating of 550 cca and you put in a 550 cca battery it'll only last so long before it is seasoned and won't start the vehicle. However, if you use a 770cca battery instead it'll go longer, not only in overall life, but with running the accessories and then being able to start the vehicle.

The 03 Tahoe Z71, according to Exide Batteries, has a cca retirement of 600 amps. The strongest battery they make for it has ratings of 880cca/1050ca and 134 reserve minutes. This is a new product line, and a very expensive battery. You'd be looking to spend $300 for it. For much less you can find a good 770cca or 850cca battery with a reserve of 120.