Greetings,
So now 1.5 months into my Lexus I have left the car in ACC mode twice and returned to a dead battery. It has caused me to ask myself a few questions that I cannot answer. I could use input from others familiar with the Lexus electrical system.
(In an attempt to ward off evil spirits that simply remark with "buy a new battery", Yes that will be on my to-do list for this week.)

So here's my puzzlement... First, as it is possible to leave the ACC on, I thought a car of this caliber would have a fail-safe to prevent the battery from draining to a "no-start" condition if left in this mode for x amount of time... It certainly annoys me compared to a key system (you would seldom walk away leaving your key in the ignition).

Second: Retuning to the car with only a orange light on, the start button obviously does nothing. I press the start button, the light goes out (which is fine, and understandably the wheel does not retract. Pressing the start only toggles the orange light on an off with no other reaction from the car....
Yup, dead battery...grrrrr
Oddly, unlike any other car, a jump also does nothing... We sat charging the car for maybe 5-10 minutes, I repeatedly pressed the start button with no reaction. At that point, the standard electronics still remained dead. On another car they should have lit immediately thanks to the other cars power, even if it was still not enough current to spin the starter. After a while, the car peeped three times, I jumped in, and the car lit and started...
Later while the car idled(Charging the battery) it again beeped once and I have no idea why...

Can anyone tell me about the delay( I assume it was by design), the beeping, or any other "feature" the lexus may show me in a near-dead battery condition?

Vince

 

I can't really answer you about jump starting. But when you leave your car in ACC or ON and leave the car with the key in your pocket the car will start beeping telling you that you left the car on, and also if you try to lock the car it will give you a long continuous beep telling you that there was an error in locking the car, which is either one of the doors is open or the car is still on thus it cannot lock the car. So there is a fail safe for not leaving your car.

 

Cars with 'Smart key system' drain the battery more than any other car that doesn't have the smart key system. That is because our cars are constantly looking at sensors for our key fobs.

There is a system. When you leave the car on, the car will beep 2-3 times telling you that it doesn't detect the key anymore.

 

Ha! I can answer this question! Why? I once left the vehicle on ACC to listen to some music and behold I fell asleep in the car!

Our cars offer nothing in particular (as far a set system goes )that tells you the battery is dying. Instead the music will shut off (or go on and off initially) and the lights on your dash and center console start to fade out (some of them anyway). Realistically it's the sign that means either "turn off your car or start it right away and let it charge!" Ironically I did this twice. The first time I watched the lights fade away. The most notable was the clock which is high noticeable when it starts to fade off. Granted I didn't fall asleep on this one. Instead I was eating some McDonald's and chatting away with some friends. I just started up the car, let it sit for a few and drove off normally.

Now the second time I fell asleep and went way past this. Most of the console lights were gone and it was basically dead. I had barely enough power to turn the igniter. In fact, I tried starting it a few times and it did absolutely nothing! I turned the vehicle completely off and called a buddy to help jump start the car. While waiting I figured I'd try to start it one more time and it came alive. SO I let it sit for a few, called my buddy to stay home and I drove around for a bit to let it recharge before going to where I was supposed to go.

And yes I fell asleep in the car at a beach because I was waiting for time to pass to make it to some event. !

 

Oh and if you walk away from your car with the acc on, you can't lock the car when you push the button on the door handle. If the engine's on, I know it beeps a few times to say "HEY THE KEY AINT IN MEH BELLY!"

And an IS really isn't a high caliber vehicle. It's high quality no doubt but remember aside from the engine, it's still pretty much a $35,000 car +/- a few for extra features and engine size. It's not like it's an LS or 7 series which has all the latest techs.

 

Thanks all,
The first time was when I told my son to use my tire pump to air up his bike tires... He took the fob, did the job, and peddled away, leaving me a dead car. Needless to say I was kinda mad, but we were home and I have a charger here, so no big deal.
The second time was for the very same reason, but it was both of us airing up our tires in the Hotel parking lot. We were anxious to get on the beach and ride, so off we went.
5 hours later we decide to head south in the car, to find it was dead again. Obviously my fault, not hearing the car chirp over the live band playing 100 feet away.
It just strikes me as odd to have a system that cannot monitor itself or time itself to prevent this.
I wonder of those batteries with reserve capacity switches still exist! I may need one!

V