Author Topic: Battery draw parked (Read 5311 times)

burningchrome · « **on:** March 14, 2009, 05:09:08 pm »

I've figured out that there is a 300 milliamp draw on my battery just sitting in the driveway. I've narrowed it to the dome/radio circuit. Is this normal?
Cheers,
Etienne

Rabbit TD · « **Reply #1 on:** March 14, 2009, 06:10:55 pm »

You didn't state what your car was, You have radios that draw a small amount to keep the presets there, the clock takes a small amount, burgular alarms, engine computers draw a small amount to keep their memory and so forth. I wouldn't worry about the small amount you are talking about though. I just re-read your post and there you go, the radio presets.

burn_your_money · « **Reply #2 on:** March 14, 2009, 06:55:11 pm »

If you are having problems with starting you may want to look at the entire cranking and charging system.

jtanguay · « **Reply #3 on:** March 14, 2009, 07:02:27 pm »

grab one of those solar battery chargers and plug it into the cigarette lighter. that should keep the battery charged if you want to store it for a while.

i have no idea what a radio normally draws, but 300mA @ 12v is like a small wall charger for a cell phone... eventually it WILL completely drain the battery... i've stored my car for months with an aftermarket radio and it held enough of a charge to start right up... did you connect the 12v to the ignition 12v, or to a constant 12v???

Rabbit TD · « **Reply #4 on:** March 14, 2009, 07:43:36 pm »

Quote from: "jtanguay"

grab one of those solar battery chargers and plug it into the cigarette lighter. that should keep the battery charged if you want to store it for a while.

i have no idea what a radio normally draws, but 300mA @ 12v is like a small wall charger for a cell phone... eventually it WILL completely drain the battery... i've stored my car for months with an aftermarket radio and it held enough of a charge to start right up... did you connect the 12v to the ignition 12v, or to a constant 12v???

He hasn't even stated he has a problem, just noticed that draw from testing or who knows.

burningchrome · « **Reply #5 on:** March 14, 2009, 07:59:14 pm »

Its an 86 jetta TD (will add to sig). I'm trying to figure out if this is an issue. The car has been hard starting and as it was cold I put it down to a glow plug issue. The car sat for a few days and then wouldn't even turn over. I am going to trouble shoot the starting system but I wanted to rule out some things first. I just wanted to verify that 300 milliamps was negligible even over the span of a few days.
Cheers,
Etienne

Rabbit TD · « **Reply #6 on:** March 14, 2009, 08:14:55 pm »

Quote from: "burningchrome"

Its an 86 jetta TD (will add to sig). I'm trying to figure out if this is an issue. The car has been hard starting and as it was cold I put it down to a glow plug issue. The car sat for a few days and then wouldn't even turn over. I am going to trouble shoot the starting system but I wanted to rule out some things first. I just wanted to verify that 300 milliamps was negligible even over the span of a few days.
Cheers,
Etienne

You can take the domelight bulb out or the fuse to it and your radio fuse too one at a time and see which one takes the draw away and go from there, glad it's not a real complicated car. My 92 Buick killed it's battery a few weeks ago. I came out from the dentists and my HVC fan was running full blast and I have the keys in my hand. I tried to start the car and it was too weak and I had to pull the fuse to the fan to shut it off first. I haven't gotten too deep into it yet but it sounds like a pretty common problem with the Climate control ones from what I've been reading, and most of the time you have to change the whole control pannel. I think a toggle switch will be a little cheaper :lol:

burningchrome · « **Reply #7 on:** March 15, 2009, 06:49:48 am »

Quote

did you connect the 12v to the ignition 12v, or to a constant 12v???

I disconnected the negative terminal from the battery and put my multimeter in series. I have removed the offending fuse but I'm still curious about the minimal draw I was seeing. How long would it take for a constant 300 milliamp draw to drain a battery.
Cheers,
Etienne

the caveman · « **Reply #8 on:** March 15, 2009, 08:44:28 am »

Spec for maximum acceptable draw is 28-30 mA. Any more than that will kill a battery in warm weather in 2 days, less in cold temps. Whenever i check for battery drains I always first suspect aftermarket radios, alarms and as always boomerangs [GPS car locators] . 300mA is way too much.

Rabbit TD · « **Reply #9 on:** March 15, 2009, 11:56:01 am »

Quote from: "the caveman"

Spec for maximum acceptable draw is 28-30 mA. Any more than that will kill a battery in warm weather in 2 days, less in cold temps. Whenever i check for battery drains I always first suspect aftermarket radios, alarms and as always boomerangs [GPS car locators] . 300mA is way too much.

Can you break it down a little and tell which one is actualy pulling the current, the dome light or the radio, if they are on the same fuse separate one from the circuit and see which one it is. I bet it is the radio myself and they have so many features today that who knows what power they might need to keep things alive in them.

the caveman · « **Reply #10 on:** March 15, 2009, 12:46:38 pm »

Is the radio an aftermarket? Can you take the radio out and disconnect it ? That would be the easiest way to find out. If it's not the radio then also make sure that there isn't something else that someone has hooked up the radio circuit.

burningchrome · « **Reply #11 on:** March 15, 2009, 02:57:43 pm »

I believe the radio is stock. From what I can tell the dome, radio, cigarette lighter and power locks are on the suspect circuit. I just took some readings as follows:
Nothing on 300 mA
dome on 1 amp
radio on 600 mA

I was going to install a new stereo anyways so when it is disconnected I will definitely take a reading. The help is much appreciated guys.