While I am waiting for my RX450h+ to be delivered....

I am wondering if the disabling of the Digital Key system in the car (Settings -> Info & Security -> Enable Digital Keys -> OFF) solves this issue.

Thanks!

Helps, but doesn't solve the issue completely. Because you can still go into ACC mode and stay there until you've successfully killed the battery, have paring with garage-door-opener/EV-charger to kill the battery by repeatedly waking up the car, etc. I deleted digital keys, never enter ACC mode, not paired anything except phone with the car, and keep the keyfobs in a Faraday pouch (or switched off) when at home.

(I wish the mods pinned the a best-practises posts in a thread for all new owners. That'd summarize and prevent repeat posts/questions about best practises and knowledge. Otherwise, as this issue will stay forever, questions will come forever - as no human will be able to parse through 1142 posts and increasing, and at some point others have to stop answering already-asked/answered questions. And this thread primarily belongs to the "Hybrid" section and is mis-categorized in the all RX upper-level - as cars without DC-DC converter, as in the ICE, are hardly reported to have this problem)

Thanks for the reply so....
.

1. Disable Smart Key - No problem, don't want to use it anyway
2. Don't use ACC mode - Bummer, but I will just turn the car on and leave it on instead
3. "Pairing" with an EV-Charger - Bummer, didn't know I even could do that but bummer
4. "Pairing" with the garage door opener - My opener is not bluetooth so there isn't any communication until you push the button. (I didn't even know there was any other kind)
5. Keeping the key fobs in a Faraday pouch - I keep our keys fairly far away from the car so I shouldn't need to do that.

If anyone else has any info please reply.

Thanks again for the summary!

I can’t speak for other’s experiences, but I’ve had the 2024 RX 450H+ for a year now. I’ve only had a dead 12V battery issue once within the first week of ownership, but since then I’ve never had any other 12V battery issues for last year.

A few habits I’ve changed just to be safe…but I really don’t worry so much about it any more.

• I store my phone and key fob at least 30 feet away. No faraday pouch needed.
• I disabled the digital key on my phone.
• I don’t worry anymore about leaving the L2 charger connected to the car overnight or even a full day. I just charge it when needed and leave it plugged it.
• I also have it paired with my garage door opener with no problems. Not Bluetooth but regular RF to the car’s Homelink rear view mirror.
• I don’t use ACC mode without the car being on. But I would never use ACC mode on any other cars either. Just not good habit.
• I use the Lexus App regularly to remote start the car and check the Traction battery charging status. No issue.
• I did notice if the battery is still hot after driving for a while, if I try charging immediately, sometimes the Battery Management System (BMS) kicks in and pauses the charging until the battery cools down.

But I also bought a NOCO trickle charger and store an emergency booster charger in the car— I’ve never had to use either for the Lexus.

Another few questions:

1. Can you see the 12v charge status via the Lexus App?
2. If so, could you just remotely start the car once a week while on vacation leaving the level two plugged in?

I am not sure if this would start the ICE or not.

Thanks!

1. You see the status of the Traction Battery (the battery used to drive the EV Motors) in the app. The 12V battery is a different battery used to maintain the electrical components of the car. You can’t see the status of 12V battery on the Lexus app.
2. You can remote start car as often as you want, and even if the L2 charger is still plugged in. You just cannot start driving car while plugged in.

Thank you for all the info!

I agree on the ACC mode, I don't use it on any vehicle.
My only struggle will be getting my wife to agree to keep her purse 30 feet away from the garage.

If I was to purchase the Ionic emergency start and my battery is dead and the doors are locked, will this unit allow me to open the doors with the electrical system as well as start the car?

EDIT: Just to clarify, will enabling the "Ionic emergency start" power the electric doors to be able to open them?

I bought exact same eyelet cable. Hooked it up to the battery and tucked it under the rear trunk lid. There’s a little opening from the battery to the storage cubby underneath the trunk lid. Works great. Never had to use it though. 🤷🏻‍♂️

Someone else can correct me if I’m wrong here, but I believe it does give enough juice to power the doors and restart the car. The only problem may be the order of operations. I think this booster is directly connected to the12V — which is in trunk. You need access to the booster by way of opening the door first.. which will not opened electronically if battery is dead. You will have to manually open the door by way of physical key on the fob and the hidden key hole on the handle, then slide in the trunk, and then push the booster button.

Alternatively, you can buy a different booster like this and jump the battery from either the battery in the trunk, or the jump start connectors under the hood. It’s also good bc the clips allows you to jump start any car battery. https://a.co/d/g4IcRhn and https://a.co/d/2fRBDbX

I believe the emergency starter can be turned on via bluetooth so I was hoping that would allow me to open the door so I could then start the vehicle.

Oh nice. I wasn’t aware. But website does show the Ionic allows jump start via Bluetooth.

Since the Ionic is permanently connected to the car and always gets recharged by the traction battery everytime you are in Ready mode, IF the Lexus 12 V battery is suddenly so completely dead that it cannot be charged back to life at all, I could conceivably live fine with the 5 A-h Ionic for a few days (carefully, by NEVER going into ACC mode), until I can get the car to the shop or dealer to replace the completely dead Lexus battery - without having to call/wait for road-side etc. This can come in handy if I'm in a remote location when the 12 V battery dies, such as in a National Park or such.

Together with the bluetooth app-based remote jumpstart ability (critically helpful for Lexus or other cars that don't allow doors/hatch to open if 12 V battery is dead) - the above is also the key feature of the Ionic that sets it apart from any other booster.

Seems like one hell of a device. Just want to make sure that it is safe heat wise and not a fire risk.

Thanks for the info!

This is getting a be a very big thread, and I'll also contribute with our latest issue. Our battery died for the second time last night in our 2023 Rx350h. When our battery dies, and we attempt to start the car, the car enters a mode where it flashes the lights on the console and the headlights randomly and quickly turn on and off. I have not found a way to stop this from happening until it completely drains the battery, which can damage the battery. Pressing the Start/Stop button does nothing. We don't have phone as a key, the ACC was not on, and my battery monitor showed that it slowly drained over three days that we weren't driving it. Granted, it wasn't at a high level after we drove it last because the battery never charged beyond a weak level.

Once the car completely drains the battery, the doors don't open without using the physical key and manual door release. The hatch won't open, so I had to google how to manually release the hatch to open it. Our charger won't charge the battery because the battery is at such a low state that the charger thinks the battery is damaged.

Rather than getting the battery replaced under warranty and possibly getting another garbage battery, I replaced it with a larger battery. The battery tray is actually large enough to accommodate a size 48 battery if you remove the plastic stop in the battery tray that holds the smaller OEM battery. I purchased the one shown below, which is rated at 67 AH as opposed to 60 AH for the OEM battery. I'll be monitoring it closely to make sure the car is charging this new battery properly, but it looks good so far.