riredale

I spoke with the local dealer about the 2010 450h I bought a few weeks ago and told him of my issue with the battery dying after just a short time of using the radio. He said to never use the Accessory position, just start the car and if/when more juice is needed the engine will start and top things off. That seems silly to me.

I noticed the other day that if I turn off the car but want to keep listening to the radio by hitting the Start button once, the headlights won't ever turn off (this is inside my carport, so the headlights are on when I shut the car down). Perhaps this is a major factor as to why the 12v battery runs down so quickly. I could turn off the "headlight delay" feature so the lights turn off immediately on shutdown, but I like having them on for 30 seconds. I think this is a bug in the system--the lights never turn off if they are on when the Accessory mode is selected.

As an aside I received that portable jump-starter I had mentioned a few comments ago. When packed into its cloth carry-case along with jumper cables and chargers it's about the size and weight of a red brick. There's a built-in flashlight and also a USB port and the thing seems well-made. Haven't actually used it yet but I looked under the hood the other day and verified the metal +12v tab where the red clip will attach and found a beefy bolt on the engine about 8" away where I can place the black clip. Actual current draw should be minimal compared to typical ICE starter motor demands. This jump-starter was only $40 at WalMart but was a mail-order-only item (free delivery to the local store).

Droid13

I do it both ways. If the system is already on often I will leave it on. In this mode the power will come of the hybrid battery and keep the 12V charged. Unless you are using the HVAC, you can sit for a very long time before the engine needs to start. If I get in waiting for somebody, instead of starting I will then just go to Accessory. No headlights.

I believe the headlight timer is started by opening the door, not shutting the car off, but not certain. I've programmed my headlights to shut off right away and they only do so when the door is opened. Sometimes when I come to a stop and waiting, but want the headlights off, I'll open and close the door to shut headlights off (you could of course simply take the lights out of auto mode while you wait as well). I haven't tried this with Accessory mode though, but something to try.

kirankom

https://www.batteriesplus.com/replac...st/35dl/sli35m

This battery was a perfect fit. The guy at battery plus installed it for me. I would imagine most BCI group 35 batteries would fit. Just make sure that the battery terminals are on the correct side, after installing, the positive terminal of the battery should be on your left side.

Mmagic76

I read somewhere that a trip to the Lexus dealer is required to reset something if I replaced the battery the old fashion way (by disconnecting and reconnecting). Has anyone replaced the battery this way before?

riredale

Well, I am a very lucky fellow. Married a wonderful woman for starters. Then just happened across this 2010 RX450h a month ago without knowing what I was really wanting. What a great machine.

Perhaps luck comes in threes. Several times now I happened to run down the 12v battery to the point that the dash lights put on a flashy show but I could not get the "ready" light. Fortunately jump-starting was readily available, but I figured the battery probably dated back to 2010 and was nearing retirement.

A couple of days ago I discovered it was possible to easily get into a menu that could show the 12v battery voltage real-time (hold down the Menu button on center console, then headlights on-off three times). Hmmm, for a lead-acid battery it didn't inspire confidence, with a resting voltage of only 12.0v and with headlights on 10.9v.

So this morning I had the local auto-repair place do a quick load test. Within 10 seconds the mechanic gave his opinion--time to replace.

I had nothing scheduled over lunch so I immediately drove to the Portland Oregon Lexus dealer and one of the service advisors said they should rerun the test, but first we needed to check with the management to see if they would be willing to cover the cost of a new battery (~$350). The General Manager said that the 12v battery was not covered under the Lexus extended warranty but since it had been only one month since I purchased the car they would handle it if their load test also failed. Couple of hours later I drove out with a new 12v battery and an invoice for $0.

This is the first Lexus I've ever owned, but I think the car is great, the dealership is very classy (like waiting in an airport lounge) and the folks there really try to please.

Droid13

I used the hidden diagnostics menu to check the voltage on my mid-2009 vintage battery. 7 1/2 years and still no issues so far. Measured 11.9V in accessory mode (not sure you can call it resting voltage considering all the electronics and display screen powered up in accessory mode, can't remember if seat warmer was on and if it's active in Acc mode). I think resting test would have to be done at the battery with everything off. Anyway, with headlights and brake lights on too, it dropped to 11.1V. In ready mode, back up to 13.9V. I haven't had any issues with it yet, but it is making it's way up on my to-do list. My Sienna original battery lasted 11 years, but the last two winters it was pretty slow to crank.

bobzaz

Replaced the OEM battery this week with the Optima 51R on a 2011 RX450h. The vent tube fits with no modification. The battery is slightly taller than stock, but the plastic cover fits well enough. It's been in the single digits this week and car starts AOK now.

I did the swap with the car powered off. Saw a screen on the display I'd never noticed.. something like 'restoring the computer'.... Everything came up OK with the exception of the rear hatch not responding to latch, fob, or dash button. I had to crawl in the truck and manually release the latch to open it. And then some bizarre sequence of outside latch to open, and dash to close to get it back in sync.

703

How did you access the hidden menu?

Droid13

From a bit earlier post in this thread, It's under the "Vehicle Signal" option. Not sure if this is consistent with later models with the upgraded menu.

Maikerusan

Having owned a hybrid for over 3 years, I don't find it silly at all.

vlad_a

There might be a reason why the hybrid 12V battery is not lasting... pre-2013 RX450h had a small battery in the boot, hence less capacity.
2013+ got the full size as well as auto-everything-off after 20 minutes. Latter is annoying for using the radio in ACC mode, however, comes in handy when wife and kids leave doors open, lights, on, etc.

Kopavi

After spending time gleaning the 12 volt auxiliary battery​​​​​​ replacement options for our 3rd Gen RX450H's and reading the various forum posts I thought I would add a few discoveries and perhaps some additional options for when our batteries need to be replaced. The current Toyota part number is 28800-31290 the original battery was a Panasonic S55D23L. The replacement options are fairly slim. An auxiliary battery with a large Ah capacity and modest CCA would is best for an RX450H since the battery is not involved in cranking.

You definately need an AGM battery since it sits in the rear hatch and is a low gas producing type of battery. Most will come with a vent tube. Some of the newer ones may not.

One of the biggest obstacles is the small area the battery sits in. I have not measured the exact space available, but one member here (John LX300) used a Bosch Platinum and it seemed to fit well and had the vent tube. If someone has the measurements and knows the exact amount of space that would be very useful.

I am on my original OEM battery made in late 2010 and use a CTEK charger to keep it in good condition. I know the day will come when it runs out of juice so I wanted to do a little preparation for when that day comes. The chart below provides the results of my findings. The Bosch appears to the best option in terms of Ah, Cost and warranty.

I was really leaning towards the X2 battery with the 5 year warranty, but I think the length could be too long.



My choice will likely to the Toyota OEM or the Bosch.

The Pep Boys site appears to offer coupon codes on batteries often and currently offer 25% off the $189.99 price. Even with the $15 core fee the price shipped to me was only $157.50. PepBoys Bosch Battery

amitmunjal

--------------------------

Hi
how did u get the Seats and hatch memory back.

my driver side SET memory button is dead but passenger side is ok.

My friends hatch has stopped working. needs to do it manually.

any help will be appreciated.

amitmunjal

hi

do u remember the sequence.

can u share them here as I have hatch and seat memory issue.

ta

Mmagic76

So what is the best way to change the battery without losing any settings? I know some use a battery tender, but what happens if we don't have that? I'm kind of weary of keeping the vehicle running while disconnecting the battery, where would the current go once disconnected?