no need to run, it will find its natural charged state by just sitting overnight. There is enough capacity in there to get the car back up and running and then that can top it off. I run the battery a lot and have never had to worry about it not starting. I dont need full capacity, just enough to start the car next time but I also dont run the battery down on consistent days in a row, which would require me most likely, to charge it in between.

 

I use the automatic lights for on but will regularly turn them off when I park to not run down the battery

 

I became a member of the "LS460 Dead Battery Club" a few days ago. After not driving my car for several days, I got in it to chauffeur my wife to an event. When I tried to start it it was DEAD,DEAD, DEAD. That was a real surprise, since the battery was only a couple of months old.

I have expressed several opinions here as to the causes of dead batteries in the LS460s so I tried to be very careful to analyze this event so I could share my conclusion with anyone who is interested.

I had to open the driver's door to gain access to the battery, via the hood release, so I could connect my battery charger. Many times the cause of the discharged battery is evident if you avoid disturbing things when you restore some power. As soon as I got the charger supplying some current I started looking for indications of the cause. The headlights were not on and the ACC power was not on and the IGN power was not on. But, the dash display showed that the left rear door was not closed. My car has the power door closers but occasionally one of them fails to close. It is a rare event when this happens. I have always suspected that there is some sort of logic problem that causes this but I have never been able to prove it.

I have explained several time in this forum that the Headlight Auto Off feature will not complete the auto-off operation until the timeout after all the doors and trunk are closed.

It seems to me that the cause of my discharged battery was the failure of the headlights to automatically turn off because the door was not completely closed.

There is no audible warning when you walk away from your car when this condition exist. Several people have explained here that a good way to guard against this type of event is to use your wireless remote key to turn the headlights off after you exit the car. You can do this by pressing the LOCK symbol twice. If you do this and all the doors and trunk are not closed you will get an audible indication and the lights will fail to extinguish.

This seems like a design weakness. If I remember correctly on the older models the auto-off timeout would begin as soon as the driver's door was opened and gave no consideration as to whether it was subsequently closed.

 

This is interesting because on my car no matter what I leave on, it will automatically shutoff in one hour. I haven't checked it in a while so it could be a little more or less than an hour, but the car does shut down anything drawing electrical power for more than an hour when the engine is not running. Actually I will qualify "anything", it will shutdown the headlights and the nav system. I personally don't know about the interior lights. I guess it's possible that an open door negates this. Anybody want to volunteer to test it?

 

I am confident that the door/headlight-autooff difficulty that I encountered accounts for many of the mysterious battery discharges that have been reported in this forum.

The auto-power-off protection only applies to the ACC power.

The interior lights will automatically go off, both door operated and spots, after a 20 minute delay regardless of the doors being open or closed. This prevents the battery from being discharged if the doors are left open or the spots are left on.

The exception is the IGN power and the AUTO Headlights. For the IGN On there is a 3 beep warning for walkaway. If the headlights are on and a door or the trunk is open there is no warning and certain battery discharge.

Here are some clips from the owner's manual: