m1964

today I had to wait for my daughter so I sat in RX and listene to music, w/ ignition button in ACC. mode-it was dark and I do not remember if the lights were ON as well (I always keep light switch in "AUTO" mode).
At one point I started the RX to get some heat, but turned the engine off after 3-5 min.
Charged my laptop for about 15 min.
After sitting in RX for 1.5 hrs, it did not start-on pressing the start button I heard noise from relays?, and a message came on the dash "check AWD system"'.

I realized that battery was the problem, waited 10 min, and it started.

In my previous vehicle (LR2) in the same situation the radio would not turn on, and I'd get a message "battery low", but the vehicle "woud not allow" to let the battery go flat.

I wonder if my RX has weak battery, or it was "too much" of current draw...
The battery does look small comparing to the battery in LR2, which was twice as big. (and probably twice as expensive-cost me $200 to replace it..)

Also, I just realized that when the radio turns off after 10 min, the seat goes back, and the steering moves forward, and when I press the start button again to turn the radio ON, the seat and steering move into my "driving position"-the LR2 did not have that feature. The two electrical motors and sound system used enough power to deplete the battery.

jmhenrie

how old is the battery? i have only had my hybrid for two months but the radio alone should not draw the battery down by itself in that time

m1964

RX350 is 10 mo. old; I also did not expect something like that happening.
I also would expect some kind of a warning saying "do not use the ACC mode" or like that. In fact the LR2 would turn everything off (radio, heated seats) if the battery was going low.
The only other current draw are the two elctrical motors that move the seat and the steering column-because the radio turns OFF every 10 min., in order to get the radio back ON, you have to push the "start" button again into ACC mode , and the seat and steering column move again...
It was raining yesterday, so after I came home, I did not want to come out again to check if the lights stay ON w/ ignition in ACC mode.

The RX started just fine this morning, but I will carry jumper cables when going out of state for New Year.

LexRexBlue

Not on my current RX, but in the past I've had "defective" batteries on my RX. The dealer discovered it during a service, replaced it. The next service they said the new one was defective and replaced that, too. The new replacement lasted another 7 years!

CoastalRX

With the car in accessory, lights in auto and dark, your lights were on. After 1.5 hours, that’s what drew down your battery. Every time you drain your battery like that your battery becomes weaker.
If you have a battery tender I would put it on over night to bring it up to a full charge. The average drive is not enough to fully charge the battery after such a discharge.

Marqevans

My 2012's battery went after two months. I noticedx the radio would shut off quickly when running on accessory when I first got the car. Then 2 months later when I hit the start button it kind of "screech". Went to the dealer and they replaced the battery. No further problem. Still fear that it might be the generator/alternator.

m1964

Thanks for your advise- I do not have the charger, but RX started up fine today, and I had no problems-did about 9-10 short trips today, and no problems.
I will keep an eye (or rarther my 'ear") on the start sound. Next service in Feb., and I will ask them to check the battery.
In fact I only decided to wait 10 min., because about 2 years ago I was again waiting for my daughter and, after the children came out, someone else could not start her SC430-she said;"I only was reading a book and listened to the radio".
I did not have cables w/ me, and it was too far from my home, so we went to a Target (5 min drive), she bought cables, and when we came back, I said"try it again" and her SC430 started...
If I need to replace the battery out of the warranty I will put something more robust.
I don't know who make batteries for Lexus, but seen some owners changing theirs after 4 years only..

wa3cuj

Your lights were on. Just open your driver side door and close it your lights will go off.

m1964

Thanks for advise-did not realize that lights stayed ON.
Anyway, apparently no problems starting, but just in case I put jumper cables in the back before taking long trip tomorrow...

mlacomb

Remember as well - short trips (10-15 minutes or less) may not fully recharge the battery from a start. If you've had a lot of short trips and then decide to leave the power on for the car, it's possible that it dipped below voltage briefly. Makes sense too that letting the battery rest for a little would get you back up to a proper voltage to start/not throw a code. Longer drives and/or a battery tender if you're doing lots of short trips or letting the car sit for a week or so will rectify this.

4482

Recently I had the NAV on inputing destinations for an upcoming trip, and deleting old ones. During this time the engine was OFF. After about 10 minutes the NAV switched off.
I was told Toyota vehicles have about a 10 minute timer the kills all electronics such as the NAV and interior lights as a safeguard in the event they were accidently left on.