Arcturus

Hello,

I went away to Europe for a week on business and left the car in the garage. When I returned and tried to start the car all I got was clicking. My multimeter gave the voltage across the terminals as 9.50V - obviously the battery was flat. I have not had problems starting the car previously and the battery is from 2011.

I have been having also been having some funny electrical problems with this car.

Does anyone know any common sources of parasitic battery drain in this car?

I just got back from another week trip and am going to test the car tomorrow. I suspect I will find the same thing.

fensterlip

There's no easy way to find it. Could be a bulb left on - most likely, Close up everything except the hood and have everything off. Put a voltmeter with a 10amp test spot in series with the negative terminal - and that terminal disconnected. BTW, turn off the SmartKey sensor under the dash near the gas pedal first. See if there's current running. If there is more than a few milliamps for the ECU then you have a drain to look for. If not, maybe the battery is older and self-discharging. If there is a drain, you need to pull all the fuses (remember or note where they went) and check again. Then put the fuses back one at a time looking for a jump in the current. If you still have a drain with all the fuses out you have a possible low current short. Fortunately for you, with Lexus that's unlikely.
If this project is a ways off, just put a trickle charger on the battery when you leave next time.

Arcturus

Thanks. Just checked again (after being away 9 days) and the battery voltage is 3.3V. I knew it was bad as it didn't respond to the key fob.

Obviously the battery is either wonky or there is a parasitic drain. I'll investigate further tomorrow. Thanks for the advice. I'll go and pickup a battery charger tomorrow and start with the drain test.

Arcturus

By the way do you know what normal drain on the car is?

Also, I noticed a while ago that there was significant blue corrosion on the positive terminal battery terminal not too long ago. I cleaned up it and it hasn't come back. Is this normal?

BMW7_LS430

When I travel for an extended duration I disconnect battery and go.
I have learned this hard way when both of my cars had dead battery upon return.

Arcturus

Did you find a fault in the system? Or was this from a normal drain on the battery?

To me a week seems very short to completely drain it.

Natey2

Arcturus, how far away from your car was your Smartkey when you went on your trip? Also, try turning the Smartkey sensor off, as previously suggested, when going away for extended periods?
There might be things using power: rain sensor, light sensor (for automatic headlights), headlight leveling, etc. Could these be active even with the ignition turned off?
Sometimes I turn my engine off and sit in my car (for a quite a while), and then I hear things whirring, coming from the air vent, I think...

Sent from an Android device using IB Automotive Group forum reader.

Arcturus

Can you confirm whether the smartkey sensor is the **** near the gas pedal in the attached picture with the red circle and arrow? What does the smartkey sensor do?

The keys I have are fobs, but I need to press the buttons on the fob to open and close the doors. Also the car has a regular key ignition not a push button.

Arcturus

Also. Maybe you guys can have a look at the picture of my battery and tell me whether the date is March 2011 or November 2003.

I'm 99.9% certain it's March 2011 (03/11), but it'd be good to confirm 100%.

Rezonans

Its 100% that your battery is 2011 year of production , and it looks still under the warranty, says 84 month on sticker, if you don't have a receipt you can pull it from lexus.com at maintenance history page.

Arcturus

Great. Thanks for confirming. The previous owner must have purchased this battery so I don't have any receipts. I'll try the lexus page as you describe.

Can you or anyone else confirm that the **** indicated is the smartkey switch?