Just another system sleep or active ?

If I leave the windows down overnight (car is in garage) does that cause any of the systems to fail to fall asleep? I've read some info that it does, and some that it doesn't. Any thoughts or facts on this matter?

BTW, I did get the car back. I hooked up my Multimeter and the battery was at like 12.3 and dropped to about 12.1, then held steady. I know the system was active as I had the hatch open and a few minutes before had the car running.

When the car was on\READY, the MM jumped up to just over 14V indicating the battery was being charged properly.

But the "open window" will be a thing as my wife does like to keep the windows down in certain temps, and it will get parked in the garage with the windows down....unless I give ten or fifteen reminders to NOT do that.

But if it has no effect on the car's system, she can continue her habits.

Thanks.

 

We commonly leave the windows down or 'cracked open' when we park the car for the night.

No issues that we know of, only one of the common battery failures in three years.

 

Lexus has not changed anything. I have a 2025 ES300h. If it sits for more than three days without use, the 12v battery is dead. The first time this happened the dealer charged the battery, said it was good, I needed to buy a battery tender for the car, and come back if it happens again. The second time it happened I told the dealer I bought this car because it was not a plug-in hybrid and their battery tender suggestion was unacceptable. I also informed them that I regretted buying this car and that I would discourage anyone else from buying one. They replaced the 12 volt battery. Now I’m fighting with them over the hybrid EV battery. As I told them, my smartphone holds a charge and recharges better than my cars hybrid EV battery.

 

Just asking, but where do you keep the key FOB's to the car? Are they close by? On a hanger on the other side of the wall from the car, or close? The car senses the presence of the FOB and that will not allow all systems to "go to sleep". I don't know if this is the issue with yours (or mine) but it may be worth looking at.

 

Thank you for your response and concern. My key fobs are kept in faraday bags when not in use so that their code cannot be stolen by thieves and stored about 30 feet away from the car.

 

What is the issue with your EV batteries?

 

Saw this advert for a "Battery Protector".

https://presale.alwaystart.com/

Anybody going to try one?

 

Something obviously wrong there. Zero issues with our two year old RX 350h and it has sat for days at times but is driven often.

 

The battery on my 2023 RX 350h was just changed by the dealer under warranty at 3 years (delivery). The car was sitting at the dealership for a few days for some warranty work and the battery died.

 

I can't see how this gadget is going to fix the failure of the vehicle to not properly keep the 12V battery from not being properly charged. IMHO this is just a bandaid where major surgery is needed. Save your money.

 

It's a great idea, but I don't think there is room on top of the rear-mounted battery. Might be able to mount it some other way though.

I already have the Ionic Emergency Start so habe no need for another solution.

 

My 2025 Rx 450h+ sat in the airport parking lot for over two weeks in late November in Sacramento. It started right up.

 

it takes about three years…I just bought a CTEK charger with battery indicator led…I’ll keep everyone posted.

 

So I bought an "Amp-Clamp" to see what milliamp draw my RX 350H is using when the following circumstances occurred. My thoughts were, the FOB is placed too close to the car when it's parked in my home garage. Our "habits" have been to drop the keys in a basket on the dryer as we enter the house thru the laundry room from the garage.

So, I clamped the amp-clamp onto the positive battery terminal, then using a $20 TAPO camera set to record 24\7, I videoed the milliamp draw under certain "Actions".

Just after closing the hatch at 9:35, the system was drawing 3,360 Milliamps or 3.36amps. "Normal" from what I've researched is 30 to 60 milliamps. So, it took the car about 26 minutes to go from the draw of 3,360 MI to 50 MI....or what should be normal.

Now, at 10:17, the system suddenly drew 450 MA. I did nothing to make this occur. But one minute later the system went back to 50 MA. At 10:45 I went to my kitchen, retrieved the FOB and went to the car to just open and close the door. As you can see the system then drew 3,690 MA. I then shut the door, and went to the Laundry room placing the key where I usually place them for 20 years. As you can see it took the car about 20 minutes to shut down (or put to sleep) the systems that awoke when I opened the door. That was a bit shorter than the first time of 26 minutes when I took the FOB "far away" to my kitchen.

At 11:19 I then moved the FOB from the dryer to the kitchen....farther away....and nothing significant occurred.

So, it appears that my original suspicion that the FOB was keeping systems awake because if it's placement close by. Well....the evidence doesn't support that.

My next "test" is I'm going to open the door, get in, start it, shut it down, and leave the FOB in the car.

 

Just for grins… wrap the fob in aluminum foil overnight. Try it for a few nights. Report back. I’m genuinely interested.

I hang my keys on a rack just inside our back door. The car is in a detached garage about 20 feet away.
we have not had a battery issue yet. Picked up the 2025 350h a year ago this week. Has just over 10k miles.
my bride drives it about 35 miles round trip four days a week. Half of that at 70mph highway speed.

People say the car does not charge while it’s being driven. I don’t know… but our car is driven quite a bit and we’ve never had an issue.