I have had my HHR radio on for 2 hours at the drive-in theater several times without any problems starting the car afterwards.

Steve

Thing is when you turn the key to ACC other things can consume power.

… and with a door or the hatch open some lights are sucking down the battery as well. There likely is a difference in the power consumed between the basic and the deluxe radio systems - that sub has to draw a fair amount I am guessing.

It hasn't always done this. It has happened twice. I had the battery tested twice and it tested good both times. I sit in my car at work and it would be nice if I could listen to the radio without having to worry about the battery dying.

Not really true in todays cars. Nearly everything is electronic right down to the injector pulses and air fuel ratios, so the battery in fact DOES run these systems. The alternator keeps the battery charged so it can keep the cars electronics happy. That's why you are NEVER supposed to disconnect a battery while a modern car is running to test alternators and whatnot like you could in the old days.

Testing "good" does not necessarily that the battery is in prime shape. Each cell should be putting out the same voltage.

Modern batteries make it seem difficult to check the electrolyte level. You can still do it, those caps do indeed come off even if they don't look like they do. After you do that you can use a specific gravity tool (hydrometer) to check each cell.


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I do at times listen to an XM Golf station. Can't get it any other way. My battery is a year old and doesn't have a problem starting.
How much does the radio draw (amps) vs how many (amps) the battery has.

Autozone / Discount Auto and others do a Free Battery and Alternator check.
When my battery died i replaced it but the CEL remained on, had them test charging system and the Alternator was the problem.
Fortunately, The Alternator is easy enough to change (as well as Serpentine belt - Cut Harbor Freight Serpentine belt tool to 11" before attempting).

Well ... Here is the ANSWER.

The only thing I am not sure of is if this applies the same to all years 2006-2011
I have a 2011 2LT so this Radio/Dead Battery thing has happened to me twice.
When I checked out how much the radio drew in amperes it was very little, and I have the factory Base unit.

When you are parked you have 2 choices.
You can put the car in Park or you can leave it in Neutral or the Drive positions.

With the Radio On;

If you put it in Park and put the Ignition in ACC you will be drawing a constant 5 Amps plus the radio draw.

If you put it in Park and the Ignition in Off, you will be drawing No extra amps , only the Radio.
The problem with this position is that the radio is on a 10 minute shut off cycle, so you have to turn the key to on and then back to off to reactivate the radio each 10 minute cycle.
This is a crappy way to make it work but that is how it is set up.
I think it is meant to be a safe guard in case the radio is left on accidentally ... it will shut off so it does not run the battery down.

My fix is to wire the radio directly to the Aux Battery lugs under the hood.
You can put a fuse in line when you are wiring it up.
This allows you play the radio separate of all the other Stupid Issues.

Silverfox

The radio only has a constant 12V. There is a RAP signal that makes it seem like it is switched. That is the problem with installing after market radios.

If you messed with the RAP the radio would play any time. That is a digital signal from the BCM on the low speed GMLAN.

I don't know why running the rd/wht wire directly to the battery would be any different from the way it is wired. The fuse is always hot.

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