wrinkle

Yep, any number of relatively simple (relative to the drive-train and such) implementations could have prevented us in not even be aware that the 12 V charging algorithm is a dud. I think that Lexus is now a lumbering corporate giant so awash in cash and profits, to have effective management that decides their design, execution and operations - and I say this not just based on this 12 V battery issue, but considering my experience with the dealers, getting the 2nd keyfob, and so on. Lexus is fat and happy. And perhaps on their way to be upended by competitors soon in the market - business leadership goes in cycles, after all. I just hope at this point that the RX450H+ that I invested into doesn't end up having any serious reliability issues like the RX500H seems to have with its transmission, longer term. I looked past pretty much every other aspect of a car to choose Lexus, only because of its past reputation of reliability.

MooneyPilot

Unless the battery dies…

WellsB

Just use the easy-to-get-to jump points under the hood...

StefanoS

You have valid points, Wrinkle. I agree that Toyota/Lexus is a bit of a lumbering corporate giant and indeed, they could be doing a better job, especially here in North America. Most large corporations are normally like this, often slow to respond, unless they have a highly functional consumer support system in place. Toyota is a very conservative organization, as are many Japanese corporations and most of their decision making is done by consensus, which is often burdensome and slows the process down dramatically. Look at the big flap with the newer Tundra 3.5L twin turbo engines failing and the length of time before things came to a head. I worked for some time as a manager for Mitsubishi Bank of California and many of us used to snicker about how it often took so much time just deciding who would go thru the door first after a meeting. A bit of levity but, not too far from the truth. I have a feeling that things are a bit different in Japan. Auto dealers in North America are huge profit centers, especially right now and let's face it, the big focus is on initial sales and the attempt to capture the very lucrative service market after the sale. I believe that the mothership will eventually get this issue with the 12v batteries resolved, especially if more of us continue to open a case at our local Lexus dealers. Engineers and Software personnel in Japan will have to be involved in the solution and perhaps there just has not been enough squawking yet from those of us in North America. The squeaky wheel gets the grease.

KrzysiekKTA

Just my 5 cents The Negative connection point for jump start cable listed in the manual is part of exactly same frame as the point I used to connect the Jump Starter with standard length cables.
See attached picture below



Brgds

K

MooneyPilot

Official Lexus jump points are on opposite sides of the engine compartment. My heavy duty jumper cables won’t reach the officially designated ground jump point. The minimum wage road service persons for the most part are not up on where not to connect, which very likely would require a very expensive repair. Two of those AAA types I sent packing cuz they didn’t give me any confidence that they knew what the F they were doing. In finding a secondary ground point with a jump starter barely worked long enough to get the doors unlocked. Once the rear hatch was opened then I could connect our 50 year old dumb charger directly to the battery. Our 3 month old RX450h+ battery went from capable of starting the car to bring a shovel and bury it 3.9 volts in four unused days. Some of the sting of a dead battery could have been alleviated by Lexus by having a manual rear hatch release in these RX’s.

jahnjva

KrzysickKTA, I went by what what the manual shows and is a lot further than your photo. I would have to look under the hood. (page 554)

MooneyPilot

That pic illustrates how inconvenient the official jump points are.

jahnjva

MooneyPilot, I agree. That's Lexus for you. That's why I bought

Schumacher Electric SL1648 Rugged Lithium Portable Power Pack

My old jump start pack wouldn't reach. The new one sits right on top of the engine in the middle and couldn't be easier.

GHN1013

So I was in garage doing some work and noticed a strange humming/buzzing noise coming from the bottom of RX (near the rear). The car was not on or driven for half a day, and the keys and phone were all far away from car. The humming/buzzing has stopped, but FWIW, but I think I heard this before on my previous RX when the car is parked.

Does anyone know what this humming/buzzing noise is, and whether this any impact in the parasitic battery issue? Thanks.

StefanoS

What you are most likely hearing is the evap system's leak detection pump cycling on.

Carbuff2

Rhetorical question:

When jump starting an engine, the negative was always supposed to be connected to the ENGINE (thereby eliminating potential resistance in connections between battery and engine). So, ANY place to clip on the engine block SHOULD be OK, right?

I fail to see the need to use the point pictured in the manual on the far-right side of the engine...unless there is some kind of battery charging module in there, somewhere.

I'll go check with the VOM meter later today to see if there is anything 'blocking' a good return to the battery..

CCGS

Something else that draws on the battery when not running that I was not aware of. Thanks for sharing. Cheers

wrinkle

Curious - Have you actually experienced any 12 V battery issues in the 500H ? I never ran into anyone reporting it for the 500H

Carbuff2

No we haven't...
500h owners get to worry about replacing the 'juddering' 6 speed transmission, instead.

+++++++++++++

My question remains:

Is it necessary to place the negative jump/boost cable on the right-hand side of the block, or was that just a convenient point indicated by Lexus?