12v battery maintenance, issues, etc.

[CPN]

14 minutes ago, RickyC said:

The only thing that is not clear to me is why the charging voltage drops of about a Volt moving gear from a drive position ( D, B, R ) to a stationary one ( N or P ) to regain a V when returning in a drive position.

That's simple. When you shift to N or P, the 12v Battery is immediately disconnected from the HV charging circuitry; hence the voltage drop...

[RickyC]

2 hours ago, CPN said:

That's simple. When you shift to N or P, the 12v battery is immediately disconnected from the HV charging circuitry; hence the voltage drop...

If 12V is disconnected from HV charging circuitry, why Toyota suggests to leave the car in P position to charge the Battery ?

[CPN]

29 minutes ago, RickyC said:

If 12V is disconnected from HV charging circuitry, why Toyota suggests to leave the car in P position to charge the battery ?

My mistake. Of course it remains connected in P.

[trashman1965]

I believe the 12v Battery is being charged all the time the car is in Ready mode. If the transmission is in neutral N then the HV Battery won't charge.

[Chas G]

Things could be a lot worse. 

I am quite happy with my Toyota Yaris Cross plug in self charging hybrid. Just plug in after every time I use the car and nothing to worry about and no inconvenience.

[HD2024]

Hi all, I’m sure the information I need is within this thread but it’s a bit overwhelming and, despite some searching, I haven’t found what I need (or at least all of what I need).

Hopefully you’ll be able to point me to the right places or summarise. Thanks

CONTEXT

Due to a medical situation I have been unable to drive my Mk4 Yaris 2022 for nearly 6 months. I know I should have done things to keep it working but, for a number of reasons, I didn’t. I now can drive again but the car isn’t working due to a flat Battery.

I’ve purchased a NOCO Boost Sport GB20 Battery pack and attempted to charge using the terminal in the fuse box. However, the alarm goes crazy and I am unable to switch it off. The car is NOT keyless entry, and all info I find about manually turning off the alarm doesn’t work as the bonnet is open and can’t be closed while the booster is connected. The second I disconnect the booster the car is dead.

As the horn is blaring, I can’t just sit in the car charging for 2 hours as it is because of my neighbours.

 

REQUEST

- Advice on how to charge the Battery (if what I’m doing isn’t right)

- Advice to shut off the alarm for non keyless entry or if I should/how to pull the horn fuse

 

Thanks in advance for any and all help

[Graham47]

Noco GB20 isn’t a charger … it’s a booster.

 It’s designed to allow you to immediately start the car, the alarm, I think, should then stop and you can run the car in ready mode to put some charge into the Battery.

[HD2024]

36 minutes ago, Graham47 said:

Noco GB20 isn’t a charger … it’s a booster.

 It’s designed to allow you to immediately start the car, the alarm, I think, should then stop and you can run the car in ready mode to put some charge into the battery.

Thanks for your fast response. I should have mentioned I tried starting the car and it wouldn’t.

From things I read this is because the Battery apparently needed to charge up to a certain level from the booster in the first place.

I have seen people use the GB40 for this but they didn’t experience the alarm issue.

[Dala]

The car Battery will  need to be removed from the vehicle and charged outside the car.

[Chas G]

@HD2024 - maybe the immobiliser is stopping engine from starting.

I would phone the Rac or Aa and get them to fit a new Battery

or close the bonnet, turn alarm off and lift the rear seat.....there are two catches under the front lip of the cushion and you have to give them a serious snatch to get them to release then connect your Noco booster direct to the 12 volt Battery. Not sure whether it will start though if the traction Battery is also flat.

Good luck.

 

[jthspace]

Think if the traction Battery goes flat, that's serious sh*t and dealer visit is the only solution.

Booster can also connect under the bonnet to the Battery connection point and a good earth.  Connection point goes direct to the 12v Battery.

[Cyker]

Did you try hitting the unlock button on the remote fob? Even the normal key should have one of those and that's usually enough to stop the car freaking out.

I'm surprised you weren't able to start the car after powering up the jump-starter though - I would have thought that would be easily enough to power the car on

I suppose it's possible the 12v Battery is so flat it's sucking up too much power out of the jump starter so the ECU and HV contactors can't be activated properly, but given the alarm works that seems unlikely...!

 

Also when you tried to start the car, did you hold down the brake pedal before twisting the key to the ignition position?

[Cowgirl]

20 hours ago, Chas G said:

100 pages in this thread.

Anyone would think there was a problem with Yaris Hybrid 12 volt batteries. 🤔

Chas, I don’t have a Battery problem but with the change of use I want to avoid one!

[HD2024]

Thanks everyone for your help.

I accessed the Battery directly under the rear seat and connected the GB20 pack. This allowed it to charge the Battery with the door and bonnet closed, avoiding the alarm.

I was able to start the car (brake pressed) and it unexpected started in EV mode with 3/4 on the traction Battery which was a relief. However the electric doors and key fob still wasn’t working, I assume because it was prioritising power to more important functions.

Drove it for 2 hours and 60 miles in a mix of local streets and 70mph roads. Turned it off and it seems to be working as it should, key fob and all. I suspect the 12v was absolutely, completely dead and am hoping it will now hold a charge.

I’ll see if it starts up on its own tomorrow and book it in for a service too (which it needs anyway).

Appreciate all the help and support.

[Cyker]

Glad you got it working! Surprised you had to connect it directly to the Battery but the main thing is you got it going.

It might still hold a charge, but 12v lead-acid batteries deteriorate a lot when they're discharged, so even it it's working it will likely be at significantly reduced capacity, esp.  if it was a factory 12v Battery which were a bit ropey to begin with.

Keep the Noco charged and handy and get the dealer to check it when you take it in for servicing, as I suspect it will need replacing...!

 

[stevejsy]

Just got back from 3 weeks holiday to a dead Yaris Cross parked in front of my work van.. Tried the Battery booster that has worked in the past but nothing! 

Is there a way to put it into neutral so I can move it as I doubt I would be able to get the dealers round first thing! like I said it is absolutely dead,

[TonyHSD]

1 hour ago, stevejsy said:

Just got back from 3 weeks holiday to a dead Yaris Cross parked in front of my work van.. Tried the battery booster that has worked in the past but nothing! 

Is there a way to put it into neutral so I can move it as I doubt I would be able to get the dealers round first thing! like I said it is absolutely dead,

Yes, you can do with a flat screwdriver remove the small cap next to heat shifter and there is a switch or similar that you need to press with screwdriver inside so you can move to N. 
If you leave the car connected to a smart charger or jump pack for longer like 20-30 min minimal you maybe able to jump start it, but then you need to properly recharge the Battery preferably overnight. 
 

[Roy124]

21 minutes ago, TonyHSD said:

If you leave the car connected to a ..... jump pack for longer like 20-30 min minimal you maybe able to jump start it,.....

That was something I said a few days back and was told that wouldn't work.  However what you say is what I had been told  earlier.

[Russ Taylor]

On 9/19/2023 at 7:59 PM, Russ Taylor said:

A week and a day away and Privacy Mode active on our Excell and started first time. Still not had an issue yet.

That was me being clever! this June we got back after a week away (car had done 2 3/4 hour 35 mile trips the day before leaving) and I went out to check 2 yo Yaris Cross was ok. Got in and put in ready mode - no problem - moved a little way on Battery and motor did not start to charge Battery - so I thought all was well.

Next lunch time went out to set off and weird warnings on screen and it WOULD NOT go into READY. Clearly 12v Battery issue.
 

I realised I had forgotten my own advice (September 23) of putting the car in PRIVACY MODE on the multimedia screen. Dork! I think if I had it would have lasted the week ok. 
 

I checked out the thread and was not happy to trickle charge (CTEK) through the under bonnet connections. Fortunately my friend John round the corner has had trouble with his Yaris Cross due to lack of miles and has a NOCO GB20! Lifesaver! John came round and instantly the car went into READY mode so I set off for my 3/4 hour journey with NOCO on board. All well and returned NOCO. Thanks John. All well today as well.

Moral - order NOCO - which is coming this afternoon and CARRY WITH YOU and it will help if you put it in PRIVACY MODE before leaving for a longish time!

 

 

 

 

[einfachGaer]

My Yaris MK 4 is now approaching 4 years, had a few low Battery cases after 1 year in winter. NOCO GB20 did very well there too!

 

Last year I fitted a small 10W solar panel to the rear window. In hope it can save me from being stranded.

A few weeks back, I went on holiday for 3 weeks. The car was outside and the sun had plenty of time on the solar panel. Coming back to a 12,6V Battery... Never seen that figure before!

After first drive (around 20mins) it dropped to 12,3V, thanks to smart charging system!

[Peachysheff]

I had the problem of the Battery being unable to start the Yaris cross again on Friday so I called the AA and they got it started straight away. I called the dealer where I had bought the car new and took it to them, whilst driving there the indicators were flashing faster than normal and the head unit didn't work. I told the garage this and when they checked the car they said the head unit needed replacing    (coincidence) maybe. They said they wanted to keep the car and offered a courtesy car but I needed to get my licence from home so they let me take my car to fetch it. I noticed the indicators were now ok but the head unit was still not working.i called them Saturday and they said the Battery was in good health, I told them that on the last service in January they had failed it on the paperwork and also the AA had said it was unserviceable when he had tested it on the Friday. I am going in to talk with a manager today to see where I stand regarding the Battery issue.

[Roy124]

Michael, with a documented history you have a good case to argue for a Battery change.   They upgraded my Corolla from 35 to 42 AHr

[Peachysheff]

Thanks for post Roy it's always better to go into a meeting with positive news. I had my meeting with the service manager today and he informed me they had replaced the head unit and the Battery. I asked if the Battery replacement was a like for like swap and he told me it was a uprated replacement and hopefully shouldn't give me any more problems, he gave me the impression that the milage I do each year (12000 miles) should have been sufficient so as to avoid the flat Battery problem. I'm now having problems logging into the myt services on the new head unit it just buffers instead of displaying the QR code and then instructs me to contact the dealer, I will have another try tomorrow just incase they have to register it with Toyota but if not successful I will pay the dealer a visit. I asked which battery they had fitted but didn't get an answer just that it had been uprated.

[jimaros]

Hi to all.

I did try a few searches on the forum but as I'm not a native English speaker I didn't get any results.

I'm having a 3 week trip next month and the car (1yo Yaris hybrid MK4) is staying at the airport.

I've contacted my dealership mechanic about solar charger and what not but he told me that it wouldn't be necessary or in the worst case I can remove the negative lead of the 12V Battery for while I'm gone and that this wouldn't hurt the car in any way.

I'll be carrying in the car a Noco for just in case but my question is: has anyone done this? Are there any drawbacks?

[Auris Geezer]

My gut feeling is disconnecting the negative lead would mean you would have to lock the car manually, the alarm/immobiliser would be inoperative, as would the electric parking brake, maybe the parking pawl on the transmission too.  I could be wrong.