Hybrid 12v battery

[Joby1]

Hello

I’ve have a 2020 new model yaris hybrid. In the last 10 days I’ve had to get roadside assistance twice as the 12v Battery was dead. First time the car had been stationary for 3 days, the second time 2 days. Dealership today checked if there was a electrical fault (no) but said it needed a full charge up, which they did. Issue is - apparently flat 12v Battery is a hybrid issue (due to of engine running from hybrid Battery mainly it doesn’t fully charge the 12v.) Apparently there have been cases of people going on holiday for 2 weeks, coming back to a dead battery. I’m concerned as over the next few months due to work I will be leaving my car a few times for a week or two at the airport.

Seems a serious design fault of Toyota when they have a strong reputation for reliability!  
Has anyone else experienced this? Does anyone have a solution? Am thinking I may well be better to sell the car and start afresh. 
Thank you for any advice. 

[Dala]

Don't have an alarm, car cameras, etc. installed?

[Joby1]

No. Dealership said due to more use of lights etc in dark weather

[Roy124]

Joby, many threads.  It is not your problem, a Yaris problem or even a Toyota one. And running the engine and not charging is a red herring. 

I am guessing you are a new owner.  You don't know whether it had a flat Battery issue before which will have weakened the Battery. 

The approved solution if you are not running is to put it in to Ready mode for an hour.  The motor will run for short periods to charge the HV Battery.  It will in turn charge to 12 v battery. 

Best result when doing this is to switch off heater, radio etc.  You are also advised not to leave the car unattended.  

You are right to wonder about leaving the car at the airport.  You might consider getting a small backup battery. All it needs to do is to start up the car systems. 

 

[Dala]

Do you drive short rides? For example, twice a week only 5 to 10 minutes?

[FROSTYBALLS]

In April 2020, Toyota gave the following advice on Battery maintenance due to cars being left for long periods without use: https://mag.toyota.co.uk/coronavirus-toyota-hybrid-car-maintenance/

It isn't just a hybrid or Toyota problem, as petrol cars and cars from other manufacturers may be affected as well. For example our 2020 i20 comes up with a Battery drainage warning a few minutes after the engine is turned off and the multimedia unit is still on.

What you haven't said is whether your normal usage is short journeys, etc. These together with electrical systems like lighting being on a lot, etc, don't help provide the Battery with a full charge.

Yes, you can sell the car, but may have a similar experience with the replacement - who knows ?

[Joby1]

Thanks everyone for your advice. 
daily I usually do 2 x 10 mile drives. 
 

I am a new hybrid owner but had my previous petrol yaris 14 years, 135,000miles. No Battery problems. 2019 left it for 5 weeks whilst in NZ, started first time on return. 

[Roy124]

Joby, you almost have to unlearn what you new. Hybrids are a step change in specification and understanding. The Battery issue might be said to be a fundamental step change in much the same way that Diesel car drivers had to learn about DPF and then Ad Blue. 

Things will change. 

[Mikw]

I can only advise this :

About once a week leave it in ready mode for an hour. It's the short journies that kill the Battery. So, if you've done a couple of short drives then - next day - give it an hour in ready mode, and that should last a week or so.

The key is "ready" mode really. If you wash the car yourself, leave it in ready mode, the engine will only come on a couple of times over an hour. Same if you put the car in the garage, don't switch off when you get out to open the garage door.

It seems to me that short periods in Ready mode deplete the Battery, but longer periods in ready mode keep it topped up.

[CPN]

40 minutes ago, Mikw said:

It seems to me that short periods in Ready mode deplete the battery, but longer periods in ready mode keep it topped up.

...and you should also add that longer periods in ready mode knock hell out of the overall fuel consumption figure per tankful! (because it's standing still - going nowhere)

[Catlover]

I don’t think so Colin. I have done the one hour in ready mode and the engine did fire up but not many times and not for long. It’s not like the engine is running all of the time.

[Cyker]

If it's in winter and the HVAC is on then it would drop the mpg quite dramatically, but with it off or in summer it is surprisingly frugal still; When I was stuck in yet another M25 closure for 2 hours (THANKS SMART MOTORWAYS) last summer, I think I only lost 1-2 mpg just sitting there in Ready mode with the AC on (albeit in eco mode) listening to music  

 

[CPN]

34 minutes ago, Catlover said:

I don’t think so Colin. I have done the one hour in ready mode and the engine did fire up but not many times and not for long. It’s not like the engine is running all of the time.

I didn't suggest it was but nevertheless, I am not going to sit there waiting for someone at this time of year without the heater keeping me warm and the windows mist free either. Quite often after immediately filling up (and the tankful average mpg zeroing) I can nurse a 60+mpg for quite some time even in this weather but if I stop and wait in ready mode for 20 mins or so, that overall tankful mpg figure will plummet by 5 mpg at least in very short order! (in this sometimes sub-zero weather we've had recently) It's mostly because the system struggles to get the ICE much above 50°C to get some temperature into the heater.... (and NO, I am not going to sit there and freeze with no heater on! 😉)

[Mikw]

23 hours ago, Catlover said:

I don’t think so Colin. I have done the one hour in ready mode and the engine did fire up but not many times and not for long. It’s not like the engine is running all of the time.

Yep, if you do it without the heater on the engine in the Yaris Mark 4 only comes on two or three times during that hour for a minute or two at most, as long as the traction Battery is well charged.

[Yaris Hybrid 2021]

Is it easier to charge the Battery with Battery charger? The fuse box contains a charging connector.

[Catlover]

54 minutes ago, Yaris Hybrid 2021 said:

Is it easier to charge the battery with battery charger? The fuse box contains a charging connector.

It could be easier but not always convenient ie if no off street parking and you have to stay with the car. A charger may take a lot longer then the one hour Ready charging, albeit a charger may do a better job as they are “smart” and can take the charge up to 100% slowly, and can recondition a Battery. A good smart charger, though, costs a few 10’s of pounds, CTEX 5 for example £70.

[Cyker]

Didn't DevonAygo say in another thread that you shouldn't use that connector to charge the 12v Battery...?

 

[Yaris Hybrid 2021]

Why?

[Devon Aygo]

16 minutes ago, Yaris Hybrid 2021 said:

Why?

There is no connection from the under bonnet starting terminal to the 12v Battery, when you connect power to the terminals you are sending power to the DC/DC converter just like the cars 12v Battery however on separate circuits that do not join.

[Catlover]

12 minutes ago, Devon Aygo said:

There is no connection from the under bonnet starting terminal to the 12v battery, when you connect power to the terminals you are sending power to the DC/DC converter just like the cars 12v battery however on separate circuits that do not join.

So, when I connect a CTEX 5 under the bonnet of the wife’s 2010 Auris hybrid what happens?

[Red_Corolla]

1 hour ago, Devon Aygo said:

There is no connection from the under bonnet starting terminal to the 12v battery, when you connect power to the terminals you are sending power to the DC/DC converter just like the cars 12v battery however on separate circuits that do not join.

Interesting. I've charged my Corolla via both the main terminal (one with the M8 stud) and the blade connector with the red cover. Both times I confirmed current flow with an ammeter and the charging took hours to complete. Are you sure the two distribution points are not joined internally?

Next time, I could pop into the boot and check if the potential does indeed raise at the Battery posts when I connect from the fusebox. But there's energy going somewhere, that's for sure.

Here's an excerpt from my owners manual. It's one of the steps that explain how to perform a 'jump start' using the fusebox terminal:

5. Start the engine of the second vehicle. Increase the engine speed slightly and maintain at that level for approximately 5 minutes to recharge the 12-volt Battery of your vehicle.

I'm aware that this is the Yaris forum, so apologies if I'm jumping to false conclusions with my Corolla example.

[QldStew]

On 1/21/2022 at 6:55 PM, Joby1 said:

Hello

I’ve have a 2020 new model yaris hybrid. In the last 10 days I’ve had to get roadside assistance twice as the 12v Battery was dead. First time the car had been stationary for 3 days, the second time 2 days. Dealership today checked if there was a electrical fault (no) but said it needed a full charge up, which they did. Issue is - apparently flat 12v Battery is a hybrid issue (due to of engine running from hybrid Battery mainly it doesn’t fully charge the 12v.) Apparently there have been cases of people going on holiday for 2 weeks, coming back to a dead battery. I’m concerned as over the next few months due to work I will be leaving my car a few times for a week or two at the airport.

Seems a serious design fault of Toyota when they have a strong reputation for reliability!  
Has anyone else experienced this? Does anyone have a solution? Am thinking I may well be better to sell the car and start afresh. 
Thank you for any advice. 

I am having the same problem, and simply fail to understand the complexity! Why two batteries with no ability for each to back up the other? Why is the control system (which seems to be what goes flat) not on THE most reliable Battery?

Toyota- lift your game! I have owned my Yaris Cross Hybrid for about a year, and this issue has caused me to call roadside assist now 4 times! they mean well, but each come up with different solutions! The local dealer is hopeless "not our problem"

[Catlover]

 

I am going to tell you what has been said by others. Making claims like "Toyota-Lift Your Game" will only be seen by forum members. TOC is not affiliated in any way to Toyota the car manufacturer. If you want to get your message across to Toyota you need to contact them via your importer .

Obviously, you are not the only one to suffer this Battery issue over the last 12 months, as you know. But it would be better if everyone was coordinated and at a set time on a set day you all contact Toyota direct, flood them out with the same message and they may "get the message" that lots of their customers are not happy.

[Cyker]

It does seem to be a combination of the Smart entry system and also people not using the cars enough. I have noticed with Toyota vehicles, esp. the more efficient ones like the old diesels and the hybrids, that they expect to be used regularly. When they aren't, that's when they tend to develop issues, and not just the Battery draining!

It is surprising to me that it is still an issue tho', given how long this 12v drain has been a problem in their older cars.

[flash22]

What market are you in (AU ?) as the Yaris cross wasn't released till late 2020, why are there 2 batteries, safety even tesla use 2 the 12v and HV - replace the 12v Battery or put a Battery maintainer on it 2019 to 22 cars had lots of Battery issues due to car sitting especially when new and coming into the country,

The battery is an AGM type* and needs to be charged low and slow the DC to DC inventor is intelligent and doesn't charge all the time, it can take up 200 miles to get a full charge or 48 hours on a charger off the car - *some new cars use a lead acid

The battery is only covered for a year a dealer with fast charge a battery then test it, it then tests good do this a few times, and it spanks the battery

 

TLDR: suck it up and buy a new battery - oem is Yuasa or ask if they will do it as goodwill