'99 A6 electrical woes

Alright, I just went and turned off the car and the radio turned off. Why did the radio come on when the jumper cables were attached? Would that somehow get juice to the radio without a key in the ignition? Other than that, I don't know what could have drained the battery. It only sat for 1.5 hours. It had sat for nearly 9 hours prior to just now, when it started fine. Interior/Exterior lights were off (I've had problems in the past with a toddler leaving interior lights on and draining the battery). I have an uneasy feeling this may crop up again when it's least needed. Luckily, I have always carried jumper cables with me.

Stu '99 A6 Avant

Jim wrote:

The radio *always* gets "juice" even if your keys are at the bottom of the deepest sea. That "always there" feed is in the tens of milliamps range at most, and is what keeps your audio system programming intact - as long as your battery doesn't die.

My Symphony/Bose head will allow turning on after the key is removed for some amount of time at least - I don't think it'll do that "forever". Not sure, never tested it. Once you turn on the radio it'll run for some amount of time before turning itself off (roughly the amount of time to hand-wash, but not including detailing the wheels, as I recall) which ought to protect a healthy battery no matter the weather.

So then, how old is the battery? And has the weather turned suddenly much colder in the last few days?

fwiw, a rear seat passenger once left her reading lamp turned on. These are well-recessed on the S4 and so I didn't even notice it when I garaged the car for the evening. Killed the battery stone dead by morning, though...

/daytripper '00 s4 6spd

I bought the car used in august of 2002, I would imaginge the battery could still be the original. I had the same reading light problem with my toddler back in november. When the battery died in November I couldn't jump it, until i noticed the water level was low. After adding a little more than a half gallon of distilled water (Wal-mart parking lot isn't the worst place to break down) it jumped easily and has been no problem since. I'm in NH (northeast US) and the last week has been incredibly cold (lows below 0 F). The car sat from sunday to sunday last week in the frigid temps and still started sunday morning (8 F). When the car is running, the dash display shows just over 14v, which is normail IIRC. Temps yesterday were in the mid 20's i believe and the car started fine when i left my house. That makes me think something was draining the battery while the car sat, or perhaps as i drove it. I had one heated seat on, climate control and the radio. No headlights, rear defrost or other large power consumers. I've been keeping a close eye on the battery since november and it has started strong ever since the first long trip we took after the Nov jump start. I guess for now I keep my fingers crossed and hope it doesn't happen again.

Stu '99 A6 Avant

Your battery is shagged :) get yourself a new one, I think its 100amp in most Audi's I know mine is, do you have voltmeter on your dash display, it should be charging at 13.8 - 14.1 volts.

If you find you are leaving lights on etc and are of that nature, get yourself a "Deep Cycle" battery, it will cost a little more, but you can run her flat as pancake and charge again with no problems, normal batterys dont like this.

You should never have to top up a battery these days, most are maintainence free

Cheers

ron

Ron wrote: > Your battery is shagged :) get yourself a new one, I think its 100amp in

I checked yesterday and it was charging around 14.5 volts. I turned on all the electrical accessories I could think of and it still held 14.5.

Stu '99 A6 Avant