What should I do if my Lexus hybrid has been parked for a long time?

As the UK government has instructed the nation to stay at home and only venture out for specific, essential reasons in light of the Coronavirus (Covid-19) situation, many of us are being encouraged to keep our cars parked if we can. Some owners of Lexus hybrids might be wondering what will happen to their car during long periods without use, particularly when it comes to the level of charge in the batteries.

The reassuring news is that no difficult car maintenance is necessary. However, there are some tips that, if followed, can help ensure your Lexus remains in tip-top condition during an extended layoff.

To recap, Lexus hybrids generally contain two batteries: a 12-volt battery (which powers systems such as the headlamps and audio) and a high-voltage hybrid system battery (which supplies the power to start the combustion engine and drive the electric motors).

The simplest way to maintain charge in both of these batteries is to simply go through the normal start procedure: press the ‘Start’ button with your foot on the brake and ensure the ‘Ready’ light is illuminated on the dashboard (you don’t have to keep your foot on the brake thereafter, but ensure your vehicle’s transmission is in ‘Park’ and the parking brake is engaged).

We recommend you put the car in ‘Ready’ mode for about 60 minutes before switching it off again and repeat the process at least once a week, providing you can carry out this procedure while adhering to the government’s advice regarding social distancing and Coronavirus (Covid-19). Please do not leave your car unattended when it is in ‘Ready’ mode.

During the time that that car is in ‘Ready’ mode, you may hear and feel the internal combustion engine kick in; this is a normal part of the self-charging process. You might be tempted to switch on the radio to pass the time, or turn on other systems, but bear in mind these will consume small amounts of electrical power so it is preferable to leave them off.

Ensure the handbrake is on; there’s no need to go for a drive, although we must stress that this procedure should take place in a well-ventilated area – something to consider if you park your vehicle in a garage.

What if my Lexus isn’t a hybrid?

Our petrol and diesel cars only have a 12-volt battery, which provides the power to start the engine in addition to the other systems mentioned above. Regular start-up of the vehicle on conventional petrol and diesel engines needs approximately 20 minutes of running to put back into the battery what you remove on start up, so to maintain this battery we would suggest 60 minutes of running at least once a week.

Is there anything else I need to do?

Whether you own a hybrid or a Lexus equipped solely with an internal combustion engine, there are a few other easy car maintenance points that can ensure your Lexus hybrid remains healthy and happy during an enforced hibernation. Again, please adhere to the latest government advice regarding social distancing.

  • Check the tyre pressures are fully inflated to the recommended level and top-up if necessary. It can be a good idea to repeat this process when you first drive your car after a long period of inactivity.
  • Clean the car thoroughly inside and out. If you are storing your car in a garage, make sure the vehicle is completely dry before you put it away.
  • If you do plan to store your car in a garage, ensure the chosen storage area offers plenty of ventilation. If the space is secure, you could consider opening one of the car’s windows a small way to ventilate the interior. If you do this, you might have to change your car alarm’s setting to prevent it setting off the intrusion sensor – please consult your car’s manual for more information.
  • It can be beneficial to leave the vehicle with the parking brake disengaged to prevent the brakes from binding, but only do this if you are certain the car is on level terrain and isn’t going to move. Ensure the transmission is set to ‘P’ for park and place wedges or chocks, if you have them, under the wheels.
  • If you have a 12V battery trickle charger, or a solar panel charger, and are confident using them, then these are a good option to keep the battery fully charged while the vehicle is stationary for a period of time.
  • If your vehicle is equipped with smart entry and start but the system isn’t operated for a long time, a battery-saving function will automatically be activated to prevent the electronic key battery and the 12-volt battery from being discharged. Battery depletion in the key is minimised by stopping the electronic key from receiving radio waves. On many models equipped with this system, it is possible to manually put the key into battery-saving mode, so please consult your car’s handbook for more information. If you aren’t planning to drive your car for a long time, consider putting the smart key in a safe place and not carrying it around with you in your pocket. This will prevent the car from ‘waking up’ unnecessarily should you happen to walk near it in your garage or driveway.
  • If the vehicle will be kept on private property (such as inside a garage) for the duration of its storage, you could consider applying for a Statutory Off Road Notification (SORN). This informs the DVLA that the car is off the road and you will receive a refund of any remaining full months of tax. However, you won’t be able to drive your car legally until you tax it again, so it is only advisable if you are positive you won’t use your car for a long time. You can read more information about how to SORN your car here.

122 comments

  1. Parked the 300 hybrid for 2 1/2 weeks and found it had a flat battery. Hiding the battery in the boot didn’t improve my humour as the vehicle was parked hard up against a wall. A question to my local service agent drew response that it was ok to trickle charge to rejuvenate but could not explain how this was to be done when you can’t access the boot or it was parked in a field near an airport for a holiday. Surely a car battery should maintain charge for a few weeks, at least!

    1. Hi Andy,

      I have had this happen to me for the 2nd time in 2 years on my RC300h, owned from new. In my case, although I only do about 4-5000m/year, I do one or two decent 40-50 mile drives a week, plus one or two 4-5 mile ones.

      Today, just like 2 years ago, I went to the car on the way to a meeting, but couldn’t open it as the central locking wasn’t responding so had to enter the car using the manual key, then realised it was the 12V battery as the instrument display was dead. Last time, the dealer, Lexus Liverpool was very good and even replaced the battery FOC but I doubt they will this time.

      The annoying thing is that you get no warning that your 12V battery is weak or low until something like this happens. I understand that on Hyundai hybrids, the hybrid battery will let you get the car started. Maybe other brands too.

      In the meantime, my wife’s Honda HRV just keeps going, never lets you down, and neither did my Audi A5 but they’re both non-hybrid cars.

      It’s a design fault for sure because the car should either have a) a warning light re low charge on 12V battery and/or b) the ability to start the car given that the hybrid battery will have at least 20-30% in reserve.

      Seriously thinking about a different brand next time, I need to be able to rely on my car and this isn’t good enough.

      Andy C

      1. Andy, had mine with same battery problem 2 years ago and Lexus said nothing wrong with the battery it must be me doing little milage 4000 a year and need to go on a long run every 2 weeks! They fully charged it and when it happened again l called out RAC home start, they checked the battery and showed me the readings that the battery would not perform under load. They charged it so l could start and get to Lexus as my car was still under warranty. They replaced it, no charge. However that one has been a pain over the last 6 moths going flat and l have been trickle charging every 2-3 weeks. I thought as there is no idea of the battery state l bought a simple battery/alternator checker which has confirmed the battery after 8 hrs trickle charge shows 12.30 and yellow light as a medium state but the figure drops 1 every 5 secs until it shows a empty light red. The little £19 machine also tests the charging rate of the alternator by leaving connected but starting the engine gives an alternating reading. At least now l know l need a new battery!

  2. Hi- my friend has a 2019 NX300h and is away for 4-5 months and has asked me to put a trickle charge on it, but as it has 2 batteries I am unsure which one to connect it to? He hasn’t done it before so he’s unsure too!! Thanks.

    1. Hello Lee, thanks for your comment.

      Please provide a Vehicle Registration so that we can look into this.

      Thanks.

  3. Of all the plain stupid comments offered by Lexus here to those many people who can’t get access to the boot because the 12V battery is dead, the most useless must be “drive it to your nearest Lexus dealer to sort it out”. It also seems impossible to find the floor hatch to open the boot from the inside. A triumph of over-engineering at the cost of common sense. How I miss my Saabs, Volvo, Superb! Time to buy a car that doesn’t demand half of your efforts to out-fool it.

  4. I left some accessory on (parking lights? door ajar?) which was enough to drain the 12V battery to 6.5V after ten days…and to prevent the Ready light from coming on. Thanks to the above thread I now know that very little current (~100mA?) at 12V will be enough to power the ECU(s) and enable hybrid battery to start the ICE. I’ll be looking for a PV panel that will fit nicely under the moonroof whenever the car is parked for more than a week! A complete list of accessories that can remain active with ignition off…and their mA draw (by operating mode if significant) would be useful! This is nothing like my first car–1959 Riley 1500.

  5. How ridiculous of Lexus to ask people whose cars wont start to take them to their nearest Lexus dealer. How can they if they won’t start?

    1. Yes bring it to the dealer you pay for the tow and buy one of the overpriced battery. 😆

      Actually if you have a 12 v battery and jumper cables you can start the car. Now if you shut it off the car battery might not fully charge or is bad you will need the extra battery to jump started again. Good luck

  6. I have a 450hl Takumi.
    If it is not used for a week it will not start.
    If I leave it longer it will not even open. Not even with the manual key.
    I have had 3 Lexus vehicles. This will be my last!

      1. Lexus’ comments are about as much use as tips on a bull!
        Happened to me and they patronizingly said “a battery doesn’t last for ever”!!?

        1. Hi Chris, how did you manage to unlock the door at the end? I am having same situation here even the manual key wont open the door. thanks.

  7. Hi there, Yesterday morning was the first day of snow here in South Wales. I powered up the ’23 NX 450h switched on both the front and rear heated windows and went back inside. Between 5-10 minutes later I went outside to find that all the doors were locked and even with the key I could not get into the car. I had to use another vehicle and returned to the car in the evening. Using the manual key I managed to get into the car and upon trying to start there was no power whatsoever. I called the Lexus Driving Assist but given the weather they are not able to attend till tomorrow morning.

    Question…. Is there a fault on the electronics whereby when the screen heaters are switched on and the battery starts to run low the petrol engine does not engage, and the system allows the batteries to fully drain?

    1. Hi David, we’re sorry to hear this.

      Your local Lexus Centre is best placed to take a look at your NX and investigate further.

      Thanks,

      Lexus UK

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