Flat battery issues - IS300H - 2019

[iousin009]

2 minutes ago, Herbie said:

Remember, at this stage we know the battery has been flattened a few times so it may be damaged and not able to accept as much charge as it used to.

For accurate measurements you really need to take the battery into the house and put it on charge for about 12 hours or at least overnight so that (a) we know that electricity is only going into the battery and nothing can be draining it or lessening the charge it's getting, and (b) this will give us a known baseline voltage to work with and we'll know it's the best that can be achieved.

Yup, will charge tonight, but won't be in the house, will do it with noco charger while Battery is fitted and then will record the voltage after fully charged, that should be our baseline, then start monitoring.

[route66]

 

1 hour ago, iousin009 said:

I'll try this, how to reach the hidden service menu?

From 200h's post above:

Quote

i am sure in the hidden service menu (press & hold menu button then lights on & off 3 times)

 

[iousin009]

Around 5PM have tested again, the voltage reading was 12.02, which makes sense as in the afternoon it was 11.95 before the start/stop cycle.

Have put my power station in the boot and connected noco 5 left for four hours and at 9PM noco was green, removed it and another test voltage is at 12.51.

 

 

I will consider this as my baseline and will keep monitoring every day same time.

[iousin009]

Checked around 9PM today, after 24 hours. Battery level came down to 12.11, managed to access the hidden services menu (thanks for the help), it's also showing as 11.90. About 35-40% Battery depletion in 24 hours. Will test again tomorrow.

[Herbie]

The problem is, you've still got the Battery connected to the car, so how do you know if it's the Battery itself or a problem with the car that's causing it to drop?

 

[iousin009]

9 minutes ago, Herbie said:

The problem is, you've still got the battery connected to the car, so how do you know if it's the battery itself or a problem with the car that's causing it to drop?

 

Yes correct, it can be either of them, I don't have the expertise to disconnect the Battery and test in isolation. After tomorrow's test I'll get in touch with the dealer and explain him what's happening and see what he says. More inclination is towards the Battery as it got flat 5 times until now and even if something major is running in the car don't think it should bring it down by 40% in 24 hours. Tomorrow will test twice between 12 hour intervals.

[ColinBarber]

The Battery shouldn't be dropping that much so either you have a damaged Battery that cannot hold a full charge or you have excessive power draw from your vehicle. Of the two I would suspect the Battery.

Given you have a Noco 5, I would fully charge the Battery and then do a repair cycle on it to see if it can restore some of that capacity and last a little longer. Otherwise you need to measure the current being drawn from the Battery once all doors/bonnet/boot are shut and the vehicle has been locked for 30 mins.

[iousin009]

2 minutes ago, ColinBarber said:

Given you have a Noco 5, I would fully charge the battery and then do a repair cycle on it to see if it can restore some of that capacity and last a little longer. Otherwise you need to measure the current being drawn from the battery once all doors/bonnet/boot are shut and the vehicle has been locked for 30 mins.

Thanks for the reply, I will do the noco full charge and repair after tomorrows test.

How to measure the current drawn after 30 minutes? Any instructions will be very helpful.

Cheers

[iousin009]

9 AM check, after 12 hours.

Voltage again down by 0.2. Have put back noco on as think by night/tomorrow it might go flat. Looks to be consistent drop of 0.1 for 6 hours.

[iousin009]

After noco fully recharges will try the repair mode, guess to be safe I will need to disconnect the Battery?

Is it ok to just disconnect take it inside the house run repair mode and then get it back and connect? Will it mess up the lexus computer? I don't mind any saved settings getting lost (like Bluetooth connections).

Thanks

[ColinBarber]

49 minutes ago, iousin009 said:

After noco fully recharges will try the repair mode, guess to be safe I will need to disconnect the battery?

I would yes. It should be okay to leave it connected but why take the risk.

Perfectly fine to run the repair cycle in place, no need to take it inside.

[ColinBarber]

Just to add, I believe you have an AGM Battery so you should be using AGM charging and repair modes.

[iousin009]

28 minutes ago, ColinBarber said:

Just to add, I believe you have an AGM battery so you should be using AGM charging and repair modes.

Cheers, Also on the noco manual it's mentioned "this node is for lead-acid batteries only" I gues AGM is also a type of lead-acid Battery?

Will the doors lock after I disconnect the Battery, keyless lock will work? Guess I can always lock with the key.

[Dealkent]

On 3/8/2021 at 3:10 PM, Brechin Slate said:

Hi Ahmed

Can of worms opened yet again..  It does sound like there's a drain on your battery.  If you're driving it and it still goes flat then there's a problem.  Have you tried the Lexus recommended method of leaving the car in Ready mode for an hour?  The engine will start and stop during that time and it's best if you have nothing drawing power like A/C, radio, lights etc.  If you've done all this and your battery is going flat within a few days then there's a bigger issue to be investigated.

Can I just clarify , are you saying it is recommended to start the engine and just let the engine run while idle for an hour ? Does  this actually charge the Battery up ? . My Battery went flat in Spain when I had to leave it behind for 5 months , my friends asked if I want them to Start it up now and then , but I thought that would drain the Battery more ! It was a nightmare getting new Battery fitted , took 5 days for new Battery to come from Madrid etc . I’m worried about it happening again , especially now because I hardly use the car now . 

[wharfhouse]

2 minutes ago, Dealkent said:

Can I just clarify , are you saying it is recommended to start the engine and just let the engine run while idle for an hour ? Does  this actually charge the battery up ? . My battery went flat in Spain when I had to leave it behind for 5 months , my friends asked if I want them to Start it up now and then , but I thought that would drain the battery more ! It was a nightmare getting new battery fitted , took 5 days for new battery to come from Madrid etc . I’m worried about it happening again , especially now because I hardly use the car now . 

Yes this charges the 12V Battery from the HV traction battery and the ICE will start and stop as needed to keep the HV traction Battery charged. Just need to make sure you have fuel in the car so the ICE can start and run as needed too. See: What should I do if my Lexus hybrid has been parked for a long time? - Lexus 

[Herbie]

3 minutes ago, Dealkent said:

Can I just clarify , are you saying it is recommended to start the engine and just let the engine run while idle for an hour ? Does  this actually charge the battery up ? . My battery went flat in Spain when I had to leave it behind for 5 months , my friends asked if I want them to Start it up now and then , but I thought that would drain the battery more ! It was a nightmare getting new battery fitted , took 5 days for new battery to come from Madrid etc . I’m worried about it happening again , especially now because I hardly use the car now . 

Yes, that's right.

Put the gear selector in P and the car in READY mode. Turn off as much as you can (radio, lights etc) so that the 12V Battery gets the full benefit of it. The petrol engine will fire up as and when needed. Leave it like this for 60 minutes a week (more if you like but not less) but don't leave it unattended or someone could drive away in it.

The 12V Battery is charged by the hybrid Battery via a DC/DC converter, which is our equivalent of the alternator. As I said earlier the petrol engine will fire up as and when the hybrid system thinks it should.

[iousin009]

So today I connected noco for about 12 hours. It went into maintenance mode soon after 3 hours. Then recordings are:

Tester - 12.48

Vehicle Signal - 12.0

It's like the Battery has capped itself at 50% mark and doesn't charge beyond this. With this information I'll get in touch with the dealer, I hope they will accept that some voodoo happened to the Battery.

Will try the repair mode after getting in touch with them. Thanks for help everyone.

[Brechin Slate]

12 hours ago, iousin009 said:

So today I connected noco for about 12 hours. It went into maintenance mode soon after 3 hours. Then recordings are:

Tester - 12.48

Vehicle Signal - 12.0

It's like the battery has capped itself at 50% mark and doesn't charge beyond this. With this information I'll get in touch with the dealer, I hope they will accept that some voodoo happened to the battery.

Will try the repair mode after getting in touch with them. Thanks for help everyone.

You might also find this video useful.  Obviously your Battery is in the boot but the technique for checking the amount of drain is just the same.  If you do this, make sure that your ignition is off and the doors are shut so nothing is drawing power.  Also take the bulb out of your boot light, there isn't a switch on mine to turn it off.  Good luck.  

 

[ColinBarber]

36 minutes ago, Brechin Slate said:

Also take the bulb out of your boot light, there isn't a switch on mine to turn it off.  Good luck.  

Better to run the wires out of the boot and close it with the meter outside - you want everything shut to properly simulate the vehicle in its normal state. Same with the bonnet if the Battery is in the front - the alarm isn't going to properly activate with it open.

An alternative is to put a torch in the boot along with a mobile phone and video call it from another device so you can monitor the meter. Or turn off the interior sensor of the alarm and remain in the vehicle so you can monitor the meter directly (not ideal but very unlikely to be an issue with the interior motion sensor).

 

[Dealkent]

On 3/11/2021 at 3:41 PM, wharfhouse said:

Yes this charges the 12V battery from the HV traction battery and the ICE will start and stop as needed to keep the HV traction battery charged. Just need to make sure you have fuel in the car so the ICE can start and run as needed too. See: What should I do if my Lexus hybrid has been parked for a long time? - Lexus 

Thanks 🙏 

[Hadrian]

I mentioned this elsewhere, but since changing the 12v Battery it's been fine and holding it's charge.

If not using the car I still put the charger on it every couple of weeks. It hasn't dropped below 12v yet.

[Herbie]

With due respect to Mike (Brechin Slate) above, don't follow the advice in that video.

The early advice on how to check the Battery itself is good, but the method of removing fuses to check which circuit is faulty is no good for modern cars.

A parasitic drain occurs when the car and all its ECUs are in 'sleep' mode, but pulling fuses and replacing them can wake up not only the ECU associated with that fuse but also other ECUs as well. When they wake up they draw power so you don't know which circuit is supposed to be drawing power and which one shouldn't, and you can't ever get a true reading.

The accepted method of tracing a parasitic drain on a modern car is to look for voltage drops across the fuses, as explained in this video here:

 

 

[iousin009]

1 hour ago, Hadrian said:

I mentioned this elsewhere, but since changing the 12v battery it's been fine and holding it's charge.

If not using the car I still put the charger on it every couple of weeks. It hasn't dropped below 12v yet.

After speaking with the dealer with all the numbers, they agreed to replace the Battery. Hopefully mine also turn out to be Battery fault only.

Cheers.

[iousin009]

Cheers for all the draw test videos, I must admit it's still out of my expertise and the car being less than 2 years old, reluctant to play with fuses, I might damage something 😞. Also my car being parked on road, it'll be difficult to try out all these ideas.

[Brechin Slate]

11 hours ago, Herbie said:

With due respect to Mike (Brechin Slate) above, don't follow the advice in that video

Happy to be corrected by a man with your sound credentials! 👍