Not starting

[Abby Peng]

Hi, 

My car hasn't been driven for 3 months, it's not starting now. Who should I call and what should I do? I have NX300H. 

Thank you very much. 

[wharfhouse]

8 minutes ago, Abby Peng said:

Hi, 

My car hasn't been driven for 3 months, it's not starting now. Who should I call and what should I do? I have NX300H. 

Thank you very much. 

Most likely a flat 12V Battery if the car has not been used for 3 months. It will need jump starting, either using one of the Lithium jump packs or from another car in the same way as any other car - see your user manual for details. You can get roadside assistance out too if you are not happy doing this yourself (such as AA, RAC etc. or Lexus Roadside Assistance depending on which you have purchased). There is also a chance that the 12V Battery has been irretrievably damaged after so long and so once the car has been started and the 12V Battery has had an opportunity to recharge (which will mean running the car for a few hours, either driving around or left standing still in Ready mode) if the Battery doesn't hold a charge properly (eg becoming flat again quickly or the car starts to exhibit any strange behaviours or warning lights) you will probably have to replace the 12V Battery.

[Abby Peng]

23 minutes ago, wharfhouse said:

Most likely a flat 12V battery if the car has not been used for 3 months. It will need jump starting, either using one of the Lithium jump packs or from another car in the same way as any other car - see your user manual for details. You can get roadside assistance out too if you are not happy doing this yourself (such as AA, RAC etc. or Lexus Roadside Assistance depending on which you have purchased). There is also a chance that the 12V battery has been irretrievably damaged after so long and so once the car has been started and the 12V battery has had an opportunity to recharge (which will mean running the car for a few hours, either driving around or left standing still in Ready mode) if the battery doesn't hold a charge properly (eg becoming flat again quickly or the car starts to exhibit any strange behaviours or warning lights) you will probably have to replace the 12V battery.

Hi, 

 

Thanks a lot for your reply, appreciated. A friend of mine has used the  Lithium jump packs (portable one) to connect. It does start the car but after we disconnect them, the car goes off after a few minutes, it doesn't stay on. Very strange 😞

[wharfhouse]

Just now, Abby Peng said:

Hi, 

 

Thanks a lot for your reply, appreciated. A friend of mine has used the  Lithium jump packs (portable one) to connect. It does start the car but after we disconnect them, the car goes off after a few minutes, it doesn't stay on. Very strange 😞

When you say the car goes off after a few minutes what actually happens? Any warning lights etc. Can you see how many bars are in the hybrid Battery (on the dash display), does the car start the engine at all (which I would expect to start up fairly quickly after getting the car into Ready mode with the jump pack? It could be that the 12V Battery is too depleted / damaged for the car to run properly - maybe leave the Lithium jump pack connected for a while before starting the car and leave it connected for a while after it's started and see if it stops again then. if you are still having problems, giving that the car has stood unused for months, I would have thought the 12V Battery would be worth changing first and see if that sorts the issues out. 

[Abby Peng]

The car will stay on when the Lithium jump pack is connected. But soon after we disconnect it from the car, the car will go off. When the Lithium jump pack is connected, I could see the Battery is charging (only when it's lower than 3 bars), it doesn't charge as soon as I start the car, only charges when the Battery shows lower than 3 bars.  I will give a try your suggested method to see how it goes. Thanks a lot.

Attached is the picture I took, there is a yellow warning sign but I couldn't find out what that means. 

[Herbie]

The 12V Battery doesn't have any charge indicator - the "bars" you're seeing refer to the high voltage traction Battery.

Sounds very much like the 12V Battery has gone to that great scrapyard in the sky, although it may be worth giving it a full 24-hour charge with a proper Battery charger to see if that helps. Even if it does, I'd still be looking at replacing the 12V Battery sooner rather than later.

I don't know the Ah rating of your Battery but it won't make much difference in this case. As a rough rule of thumb, it would probably only take between maybe 4 to 5 weeks to go from fully charged to fully discharged if its not used, which means that its been stood in a completely depleted state for a long time and will no doubt be damaged by now.

[wharfhouse]

29 minutes ago, Abby Peng said:

The car will stay on when the Lithium jump pack is connected. But soon after we disconnect it from the car, the car will go off. When the Lithium jump pack is connected, I could see the battery is charging (only when it's lower than 3 bars), it doesn't charge as soon as I start the car, only charges when the battery shows lower than 3 bars.  I will give a try your suggested method to see how it goes. Thanks a lot.

Attached is the picture I took, there is a yellow warning sign but I couldn't find out what that means. 

Yes that's normal about the 3 bars and so sounds like the hybrid Battery is charging properly then. So it does sound like the 12V Battery is the problem and so it probably either needs replacing or given a full overnight charge with a charger/conditioner rather than trying to do it via the car.

[NemesisUK]

What do you mean, the car goes off? Does the engine start then stop? Does the dashboard show the Ready light when the engine is off?

Once in the Ready state the 12v Battery has no ongoing function and will be recharged by the traction Battery. The traction Battery will supply all electrical needs, with the engine cutting in and out to maintain the required charge in the traction Battery shown by the bars in the display.

[Abby Peng]

1 hour ago, Herbie said:

The 12V battery doesn't have any charge indicator - the "bars" you're seeing refer to the high voltage traction battery.

Sounds very much like the 12V battery has gone to that great scrapyard in the sky, although it may be worth giving it a full 24-hour charge with a proper battery charger to see if that helps. Even if it does, I'd still be looking at replacing the 12V battery sooner rather than later.

I don't know the Ah rating of your battery but it won't make much difference in this case. As a rough rule of thumb, it would probably only take between maybe 4 to 5 weeks to go from fully charged to fully discharged if its not used, which means that its been stood in a completely depleted state for a long time and will no doubt be damaged by now.

Thanks a lot for your comments. 🙂

[Abby Peng]

56 minutes ago, wharfhouse said:

Yes that's normal about the 3 bars and so sounds like the hybrid battery is charging properly then. So it does sound like the 12V battery is the problem and so it probably either needs replacing or given a full overnight charge with a charger/conditioner rather than trying to do it via the car.

Thank you very much for your help.     Sure, I will try to recharge the 12V Battery first and then if it doesn't work I will replace the Battery. 

Any chance anyone knows where is the 12V Battery in the car? Mine is NX350H. 

[wharfhouse]

12 minutes ago, NemesisUK said:

What do you mean, the car goes off? Does the engine start then stop? Does the dashboard show the Ready light when the engine is off?

Once in the Ready state the 12v battery has no ongoing function and will be recharged by the traction battery. The traction battery will supply all electrical needs, with the engine cutting in and out to maintain the required charge in the traction battery shown by the bars in the display.

Regards the OP issue, I was wondering if the 12V Battery is totally shot / zero charge and won't accept a charge whether the car then shuts down even though the hybrid Battery takes over running the electrics?

[wharfhouse]

1 minute ago, Abby Peng said:

Thank you very much for your help.     Sure, I will try to recharge the 12V battery first and then if it doesn't work I will replace the battery. 

Any chance anyone knows where is the 12V battery in the car? Mine is NX350H. 

Sorry - I don't have the NX so not sure where it is - probably one side of the rear luggage area or if not maybe under the rear seat?

[Herbie]

15 minutes ago, Abby Peng said:

Any chance anyone knows where is the 12V battery in the car? Mine is NX350H.

Usually somewhere under the floor of the boot. However, if you go to https://www.lexus.co.uk/owners/about-my-lexus/manuals then you should be able to download the one for your car and it'll tell you in there.

[wharfhouse]

1 hour ago, Abby Peng said:

there is a yellow warning sign but I couldn't find out what that means. 

I think that may be because the car has been started with the door open

[Herbie]

25 minutes ago, wharfhouse said:

Regards the OP issue, I was wondering if the 12V battery is totally shot / zero charge and won't accept a charge whether the car then shuts down even though the hybrid battery takes over running the electrics?

Complete guess, but I'd say that's logical and is probably what happens.

When starting the car the first thing in the chain (or at least one of the first) is that there are two 12V relays that work together as a safety interlock. If the 12V Battery doesn't have enough power to operate those then the hybrid system is inaccessible. Maybe the interlock is set up to somehow operate as above as well, although I don't know how they'd achieve that.

[Ken R]

Battery is under the boot floor (left hand side) in the NX if my memory serves me correctly.

[Abby Peng]

4 hours ago, Ken R said:

Battery is under the boot floor (left hand side) in the NX if my memory serves me correctly.

Thanks for the information. 

[Abby Peng]

4 hours ago, wharfhouse said:

I think that may be because the car has been started with the door open

Oh yes, you are right we left the door open.

[Serguei]

You probably need a new Battery. It is what, 5 years old?

 

[Caspa]

7 hours ago, NemesisUK said:

What do you mean, the car goes off? Does the engine start then stop? Does the dashboard show the Ready light when the engine is off?

Once in the Ready state the 12v battery has no ongoing function and will be recharged by the traction battery. The traction battery will supply all electrical needs, with the engine cutting in and out to maintain the required charge in the traction battery shown by the bars in the display.

My understanding is the same as Nemesis, only function of the 12v Battery is to start the car.

I had to get Lexus road side assistance out a couple of times for it on my RC, and was advised to replace after the second time as it definitely wasn't holding charge, but once on it was always fine. Same was true even on the occasions when I managed to start it after multiple attempts, as I really didn't want to wait for LRA, aka the AA. 

[RONNIE W HODGEKINSON]

Left Hand Side in The Boot..Its definately your 12v Battery That needs Replaced ASAP Battery cels in the Battery have been Destroyed and no Amount of Charging will Remedy This ..AND I would Advise you to take it to The Lexus dealership To Have the Battery Replaced as the Tech Guys Fully Check and Tweak The on board Computer Dynamics Connected to the Battery..Over to you..!!!

[Scotlex]

36 minutes ago, RONNIE W HODGEKINSON said:

Left Hand Side in The Boot..Its definately your 12v battery That needs Replaced ASAP Battery cels in the Battery have been Destroyed and no Amount of Charging will Remedy This ..AND I would Advise you to take it to The Lexus dealership To Have the Battery Replaced as the Tech Guys Fully Check and Tweak The on board Computer Dynamics Connected to the Battery..Over to you..!!!

Yes, I would agree. New Battery from Lexus.

 

[Abby Peng]

On 9/10/2024 at 12:30 PM, RONNIE W HODGEKINSON said:

Left Hand Side in The Boot..Its definately your 12v battery That needs Replaced ASAP Battery cels in the Battery have been Destroyed and no Amount of Charging will Remedy This ..AND I would Advise you to take it to The Lexus dealership To Have the Battery Replaced as the Tech Guys Fully Check and Tweak The on board Computer Dynamics Connected to the Battery..Over to you..!!!

Thank you very much. I have charged the 12v Battery and now the car is back to live again! 🙂

[wharfhouse]

26 minutes ago, Abby Peng said:

Thank you very much. I have charged the 12v battery and now the car is back to live again! 🙂

If you have any further issues such as not being able to start the car after a few days or what seem like spurious electrical faults change the 12V Battery straight away as given what happened it may now be damaged and never fully recover. 

As an example, though it was on my yacht rather than a car, we had a flat starter Battery (for our diesel engine) after leaving it for a couple of months. We tried to trickle charge the Battery for a while but it didn't put much charge into it. We have a second Battery and so started the engine from that and then allowed the alternator to recharge the starter Battery as usual for an hour or so. However we found that the Battery wasn't holding charge for very long so planned to replace it. We had to motor for a couple of hours though and so the alternator was charging the Battery during that time. We suddenly started smelling something and when we looked at the starter Battery it was smoking - literally boiling the acid inside and very hot to touch. Luckily we were minutes from our destination so arrived there and switched everything off and then got the Battery out and off the yacht. It took quite a few hours to cool down. Before discharging fully the Battery had been working OK and so something during it's complete discharge had gone very wrong inside it.

[Abby Peng]

9 hours ago, wharfhouse said:

If you have any further issues such as not being able to start the car after a few days or what seem like spurious electrical faults change the 12V battery straight away as given what happened it may now be damaged and never fully recover. 

As an example, though it was on my yacht rather than a car, we had a flat starter battery (for our diesel engine) after leaving it for a couple of months. We tried to trickle charge the battery for a while but it didn't put much charge into it. We have a second battery and so started the engine from that and then allowed the alternator to recharge the starter battery as usual for an hour or so. However we found that the battery wasn't holding charge for very long so planned to replace it. We had to motor for a couple of hours though and so the alternator was charging the battery during that time. We suddenly started smelling something and when we looked at the starter battery it was smoking - literally boiling the acid inside and very hot to touch. Luckily we were minutes from our destination so arrived there and switched everything off and then got the battery out and off the yacht. It took quite a few hours to cool down. Before discharging fully the battery had been working OK and so something during it's complete discharge had gone very wrong inside it.

Thank you very much for your help. We have charged and repaired the 12v Battery and now the car is all good again!