I've owned 5 new Lexi, including a second generation LX, and the battery drain problem for me has only occurred with my 3rd gen LX. All the others could sit for up to a month and would start right up. While I owned the 2nd gen LX470 I had another car I enjoyed driving more as my daily transportation, and the LX470 would frequently six for up to a month. When I traded it in, it was 7 years old with 34,000 miles, original battery, and had started every time.

Recently I installed a driving monitor from my auto insurance company, and the added drain from the monitor would kill the battery overnight. They paid for a new battery, and the same overnight drain continued, so I sent the monitor back without completing the monitoring period for a discount. After removing the driving monitor, things with the battery are back as they were before.

 

 

I agree totally.

 

I don't have any monitoring insurance device on board.

However, I do have dash cams. But these are connected via the cigarette lighter which the power is cut off when I turn off the LX570. So there is no "draw" once the LX570 is turned off.

 

Thanks.

Hummmm.......this is interesting.

I will relocate the key fobs as far away as possible to see if there is any difference.

 

[Delete, posted in this forum by mistake]

 

use this test to find the bad circuit

i would not expect the dealership to find this sort of defect, unless you luck out and have a truly smart technician assigned to your car.
but if you go in and say: "this one circuit X has a big parasitic draw"....then they kind of have to work on the right area

So many circuits with a mind of their own.....

 

I forgot to post what the Lexus dealership found after repeated visits to two different Lexus dealers. Lexus of SD (selling dealer) had no clue what’s going on back then and may still have no idea. I went to the Longo Lexus where I had taken my prior Lexus vehicles for services. Longo Lexus was able to isolate the parasitic draw due to a defective “board” for the center console fridge!!! It was covered under “EXTENDED WARRANTY” that I had bought from Lexus when I bought it brand new. I had to sign paperwork that stated if the diagnostic was found to be an item not covered by the extended warranty then I will have to pay the diagnostic bill (I remembered it was like around $300 or so). But it was covered so I only paid like $100 deductible (as I recall).

No further problems ever since. It’s been several years.

 

First, we don't know why bc thinks that "Lexus will do almost anything possible to deny warranty coverage." Pappy 97, the OP, surely disagrees. I've owned five Lexus cars via two dealerships since the original SC400, and I have not encountered anything close to that.
Quite the contrary: I had a dying battery problem on a new Lexus RC about 10 years ago, and Lexus and the dealership went way out of their way to find and eventually solve the problem. I was quite impressed; I wrote a letter to the General Manager and the Service Manager thanking them for their efforts with my vexing problem.
During that situation, I learned that keeping the key fob in or close to the car can drain the battery in the fob and even in the car, because they are constantly trying to talk to each other when in close proximity. (See Gordj's question above.) Store the fob away from the car or put it in something lined with aluminum, as that blocks the signal from the fob. (Or wrap it in alum foil.)
Since then, I always keep a battery jump starter in the car. These devices (batteries), which eliminate the need for jumper cables and for a second car, are very small, yet powerful enough to jump a passenger car several times (some of them, many times). Highly recommended. I bet Pappy97 has one of those things now. (Search for "Car battery jump starters" to begin your shopping.)