jerzy1209

I am having an issue with my 2008 IS 350. What happens is the battery dies after my car has been sitting more than 4 hours. I have taken it to the dealership twice and they have kept it for 3 days but the battery draw did not happen over the 3 days. I brought the car home and the next morning , I did not have power and had to jump my battery. It's rather frustrating. What other options do I have or suggestions are welcomed..

DennisMik

If this problem is consistent, try this experiment. When you park the car for the night, disconnect the battery cables. In the morning, connect the battery cables and see if the car will start. If the car starts, there probably is some kind of drain on the battery. If the car does not start, than the battery is bad.

What you should also do is measure the battery voltage when you park the car. It should be 12.5 volts. In the morning it should still be 12.5 volts. If the car does not start, measure the battery voltage again. The battery voltage should still be at least 12 volts. If the voltage has dropped down to 11 or 10 volts, the battery is bad.

Gville350

iTrader: (10)

Check out the trunk light to see if its the culprit. I recently started having issues with my trunk light; so I simply disconnected it.

jerzy1209

Thank you... I will check it out..

jerzy1209

Thank you... I just replaced the battery 8 days ago with a new one but I will try this test as well..Thank you

2013FSport

iTrader: (2)

A fully charged battery should be closer to 12.75 12.85v. O/T but AGM batteries sit at 12.95v to 13.00v.

A couple of dome lights or a single trunk light on typically won't kill a battery in 10hrs. That said it does keep other systems alive like it could leave the exterior lights on if caught in the wrong state at the wrong time.

You could go through a lot of videos but here is the nutshell story. You need an AMP meter capable of reading up to 10Amps but down to micro amps.

Mind you a 10Amp meter will be damaged by turning on pretty much anything in the car like even opening the door could over current it and blow its fuse. What I am saying is there is a simple work around you just have to work smart to gather data.
Unlike a volt meter placed across a circuit, an Amp meter must be inserted into the circuit by removing a terminal from the battery and connecting the meter to the battery and the other lead to the free cable. But you don't want to break this path as it resets several systems and enables things that were off.

To do this; Loosen the terminal on the negative battery cable.
Turn the vehicle off and connect a small jumper capable cable from the battery post to the cable.
Lift the cable from the post being sure to maintain the connection.
Connect your AMP meter just as the jumper cable is. One lead to the battery post and one lead to the cable. Set the meter to AMPs DC of roughly 10 Amps.
Disconnect the jumper cable from circuit. You amp meter now measure current draw from the battery.

If you're interested in knowing more I'll post up. For now, 95% will opt out of getting their hands dirty and I have better things to do.

Good luck.