2013 Rx450h. Power button doesnt switch on.

[truth450h]

Hello all,

I tried searching the forums for something similar to my issue but couldnt get an exact match. I was hoping someone could help point me in the right direction.

I had left my vehicle parked for 2 weeks while on a vacation and when i came back the vehicle refused to start. The power button was working at this time. It appeared that the Battery might have discharged. So i got a portable charger and used the charging point under the bonnet to jump start the car. The vehicle started properly and like a fool, i thought it would be enough to drive it for 20 mins or so to get the 12v Battery charged up. I did that and all seemed fine. 

Unfortunately i had to leave vehicle parked for another 1 week without driving it. This time i saw that the power button did not switch on at all. I tried jump starting as before but the power button remains off and the vehicle doesnt start.

What have i tried so far:

-the key seems to be charged as i can see a red light blinking when i press the buttons

-i tried leaving the portable charger on for 15 mins to get some charge into the Battery.

-I tied opening and closing the doors and then waiting for 10 seconds while the charger was charging.

 

I was wondering if I should get a new 12v Battery installed, would the problem be rectified. (i need to figure out how to unlock the boot door from inside to access the battery). But i am not sure if there is a blown fuse issue somewhere. Its not clear which fuses need to be checked in this situation.

Any advice would be highly appreciated.

[Herbie]

Each time the 12V Battery is allowed to go flat it sustains a small amount of damage that lowers its capacity and the amount of time it stays flat also contributes to this. As a random example, if it used to take a full 100% charge it may now only take 80%. Depending on the age of the Battery and how often this has happened, it may be time to replace it.

However, it's worth a try with a good Battery charger first, before you spend any money. I would give it a full 24 hours on charge, or at the very least, overnight (NB - as long as you have a modern 'intelligent' charger and not some 40 year old transformer-based thing) and see if that helps. If not, then it's time for a new one.

[truth450h]

29 minutes ago, Herbie said:

Each time the 12V battery is allowed to go flat it sustains a small amount of damage that lowers its capacity and the amount of time it stays flat also contributes to this. As a random example, if it used to take a full 100% charge it may now only take 80%. Depending on the age of the battery and how often this has happened, it may be time to replace it.

However, it's worth a try with a good battery charger first, before you spend any money. I would give it a full 24 hours on charge, or at the very least, overnight (NB - as long as you have a modern 'intelligent' charger and not some 40 year old transformer-based thing) and see if that helps. If not, then it's time for a new one.

Thanks for the suggestion Herbie. I will try that out, weather permitting. 

If that doesnt work, does anyone know how i could unlock the boot from inside the car so that i can access the 12v Battery? I had a quick look and i couldnt detect anything obvious.

[steveledzep]

Lower one of the back seats and climb into the bootspace.  Take a torch and small screwdriver.  In the centre of the tailgate, just above the lock there is a small panel that you can prise out using the screwdriver.  Reach in here with a finger and you can slide the mechanism sideways to release the tailgate.  Take a piece of 2x1 timber in too, slide this under the open tailgate otherwise it will close while you clamber out again.

[Illogan]

4 hours ago, steveledzep said:

  Take a piece of 2x1 timber in too, slide this under the open tailgate otherwise it will close while you clamber out again.

This is how to be wise before the event!!!! 👋

[Bluemarlin]

I had something similar, where the power button wouldn't work, can't remember what caused it. However, what fixed it,  apart from the door opening/closing thing,  was to hold the fob next to the power button when pressing it.

[Barry14UK]

I agree with Herbie that in  probability you need a new Battery for the reason he gave.  In effect, I was in a similar position with a  locked down tail gate when I deliberately disconnected the Battery negative to do some work on the car.  However, I did first remove the the Battery cover so that I could more easily open a rear door and reach the Battery connection. But you should be able to fold up the cover and release the plastic fixers that secure the compartment cover and either clip a good smart charger to give a long charge or connect a spare Battery.  I did have to reinitialize the tailgate after, also windows, and sun roof, also reprogramme radio stations.

Where a Battery is flat and will not accept a charge, sometimes it can be made to do so by correctly coupling a second OK Battery to it and charging the two as an entity for at least 24 hours.  However, this may not work well or for long.  A new Battery is a much better solution and never let it go near flat again.                       

[truth450h]

Thank you for the pointer steveledzep. That worked perfectly.

I wasnt able to charge the Battery for a very long duration. I got a few hours of charging but that didnt work. So i went ahead and bought a new Battery and replaced the old one.

I found out that the old one was a 2017 vintage so perhaps that was not a terribly bad idea.

I got a Hankook AGM Battery. (https://www.batterymegastore.co.uk/product/hankook-sa55020-agm-car-battery-uk-part-code-063h/) for 97 £ as the OEM one was much more expensive (close to 197 £ on lexusparts direct).

I needed a ratchet wrench to get the 10mm nuts off the Battery holding bar. The Hankook doesnt have the same dimensions as the original panasonic Battery. Its not as tall. So I put a base at the bottom to raise the height so that it stays tight and firm.

there was also a bit of water at the bottom of battery compartment. I think there is properly a gasket leak somewhere with the rear door. Couldnt detect anything obvious. Drained the water and wiped it dry before i put the new Battery in.

It worked well. As soon as i connected the negative (after i connected the positive) the car's alarms started blaring. Gave me a start! 🙂

I took the car on a 30 min drive (around 11-12 miles) to get the 12v a bit of a top-up and to check if all was well and the settings were retained. Everything looks fine now.

2 outstanding questions:

1. The Hankook AGM didnt have a vent like the OEM Battery did. I thought all AGM batteries have vents. I had to leave the vent pipe disconnected. Hopefully this is fine and I havent missed something obvious?

2. With all the work from home situation I might have spells of not needing to drive the car for a week or 10 days sometimes. How often do i need to drive the vehicle to ensure the 12v doesnt discharge ?

 

 

[steveledzep]

I bought that same Hankook Battery when I had my problems about two years ago.  Everything has been fine since.

To occasionally charge the 12v Battery, you don't have to take it out for a spin.  Just put the vehicle into Ready mode and the 12v Battery will be charged as required.  Be careful though as anyone could steal the vehicle off your driveway, make sure it's blocked in somehow.

[Barry14UK]

15 hours ago, truth450h said:

 

1. The Hankook AGM didnt have a vent like the OEM battery did. I thought all AGM batteries have vents. I had to leave the vent pipe disconnected. Hopefully this is fine and I havent missed something obvious?

 

 

 

I am sure your newly purchased Battery does have provision for a vent pipe as shown in the picture of this Battery.  I replaced the original Panasonic VRLA AGM Battery in my car with a Halfords (Yuasa) Battery.  I had to prize out the transit plug in order to fit the vent tube and indeed use an alternatively purchased connector because the Panasonic one was too large for the new Battery.

The VRLA (Valve Regulated Lead Acid) Battery benefits from the vent to outside where in the event of the valves opening, largely due to overcharging, gas is safely expelled  to outside.  The valves are less likely to be tripped in your car than in a more conventually alternator charged one but if you use a Battery charger at some point the could happen. 

So it's really up to you as to whether to incorporate this safety vent that Lexus fitted.  Omitting it could could adversely affect the Battery warranty if you had a problem as Hankook say will be the case if the Battery fails due to the voltage falling below a figure they give. (If you just prised out the transit plug and omitted  the external vent, gas could be released into the cabin). 

PS. Some batteries come with a vent position at each end so you use the most convenient one and leave the plug in place at the other end.

[truth450h]

16 hours ago, steveledzep said:

To occasionally charge the 12v battery, you don't have to take it out for a spin.  Just put the vehicle into Ready mode and the 12v battery will be charged as required.  Be careful though as anyone could steal the vehicle off your driveway, make sure it's blocked in somehow.

Thanks Steve. that is useful to know.

 

6 hours ago, Barry14UK said:

PS. Some batteries come with a vent position at each end so you use the most convenient one and leave the plug in place at the other end.

Thanks Barry. I thought that might be the case. I will try this out. I had removed the transport bungs before installing the Battery but the outlet tube didnt fit the vent on the Battery. So i left them open. I need to get some kind of adapter to fix the tube to the vent.

[Barry14UK]

I bought my right angle replacement connector off eBay. I think they are mostly standard and a push in interference fit.  It came with a few inches of thin wall plastic tubing which I set aside for some other use. The connector on mine is white but I don't think the colour matters.  The existing Lexus vent tube then fits directly to your new connector.  You could keep the one used with the Panasonic Battery for anybody who wished to revert to the original Panasonic Battery in future.

[truth450h]

On 11/13/2022 at 2:14 PM, Barry14UK said:

I bought my right angle replacement connector off ebay. I think they are mostly standard and a push in interference fit.  It came with a few inches of thin wall plastic tubing which I set aside for some other use. The connector on mine is white but I don't think the colour matters.  The existing Lexus vent tube then fits directly to your new connector.  You could keep the one used with the Panasonic battery for anybody who wished to revert to the original Panasonic battery in future.

Just to close this, for the benefit of anyone else who might have a similar problem.

I took your advice Barry and got this from eBay. (https://www.ebay.co.uk/itm/392875277300 ). Fits just right.

Thanks for the help everyone.