12v battery maintenance, issues, etc.

[Cyker]

The car's still new enough I could understand being unaware; Even dealer salesmen aren't all that aware it's an issue due to it being limited to certain use-cases, which is why we try to make potential new owners aware of it on here when they ask, rather than try and gloss over it.

 

[tfc]

Last Tuesday the nextdoor neighbour picked up his new Yaris design and the salesman told him how to jump it if the Battery goes flat which he thought was a strange thing to say while showing him around the car. 

Anyway it's been parked up since he collected he's gone away for 2 weeks down south in his other chariot.

I never did any research when I bought mine, I saw it ,liked the look of it and bought it there and then, and I hardly drive it , and I don't loose  any sleep wondering if its going to start or not , and for fuel efficiency that's another thing I'm not concerned about,  its doing better mpg than my i30 did and I'm  happy with that , I think It's 45 mpg which is 15 better than the i30.

[Dala]

Interesting if they implement this information on other products.
If you don't watch TV at least twice a week, you will have to tune in again.
Or
If you do not open the front door to the house once in 14 days, you will have to go out the window for the first time.
🙂

[anchorman]

1 hour ago, Max_Headroom said:

Try - Yaris hybrid  problem 2022 -

That'll give you the link to the 8 page 12v battery problem thread  😉

We know all that but it means nothing.  The forums attract owners with a problem but what you can’t quantify are the ratios.  Those 8 pages might include 90% of the country’s problems and if you whittle them down you’ll probably find multiple quotes from the same owner - they don’t all count as separate complaints.  I don’t know why an owner should research problems - for most they are out shopping for an appliance.  I do think the dealers should do more to test the likelihood of problems but of course, they don’t want to scare away potential customers.

[IT Troll]

4 hours ago, Cyker said:

The car detects when the 12v battery has dropped below a certain threshold then disconnects it.

Now that is a more sensible approach, compared with just continuing to drain the Battery until the car is inoperable.

When I test drove the demonstrator it only had standard Speakers. I asked to hear the JBL system in the showroom model and the salesman had to boost the car in order to turn on the multimedia system. Turns out this was a useful instruction for a future real world scenario! So I was well aware of the issue. Imagine if the salesman could have said, the car has been sat here for a few weeks, but thanks to Toyota’s renowned reliability, I just have to press this single button…

[RickyC]

5 hours ago, Cyker said:

Originally the traction battery had to be disconnected when the car was off, necessitating a 12v battery in order to power up the contactors. I think it was primarily for safety reasons rather than security - Having a high-voltage system connected all the time was presumably deemed an unnecessary risk.

That said I don't know if that's required any more, given Tesla and Hyundai EVs seem to have their batteries connected all the time now in some cases!

The Hyundai/Kia system, AFAIK, doesn't connect the traction battery to charge the 12v battery - The car detects when the 12v battery has dropped below a certain threshold then disconnects it.

Sorry, I used the wrong word.  Safety is the correcct word.

EV cars must have HV system active also with parked car due to the need to recharge the Battery. But probably also EV cars isolate HV Battery when car is not connected to a charger.  

But are you sure that if you leave a Tesla or a Hundai for 2 o 3 weeks without using it, it will start again without the need of jump cables ?

I think it's not so easy to implement a solution similar to the Hunday/Kia one in Toyota cars.

Probably the best thing is to redesign the charging circuit suppliing more currento to 12V during recharge.     

[CruxisCore]

I researched quite extensively, but ofc about Yaris Cross (as I was not buying a regular Yaris) so it might be cos of that, as there's much less stuff about the Yaris Cross in general yet. This is the only place where Battery problems came up in bigger amounts and I didnt even find myself here until I had already ordered the car. I found more references to rusty rail under the front seats than I found about 12v problems.

Now in a few different hybrid Toyota groups I do notice it's a trend. Not a big one but here and there people reporting different hybrid toyotas having flat 12v after some days of absence.

Well, this thread might have enough info on it by now, but most mentions of flat 12v just have way too many variables to think much into it, since you dont know usually anything but "i have a Yaris and I was gone 3 days and Battery flat", while the real causes are outside that sentence.

Not worried for myself personally with around 30k a year of driving, but probably will still get one of those small jump starters. If not for me, maybe it saves someone elses day 😄 Also have a CTEX MXS 5 so maybe use that a few times in the winter just to be sure, since I opted for most of the passively Battery draining bells and whistles 😄

[Roy124]

20 hours ago, Max_Headroom said:

Didn't SAAB make planes before cars  😉

 

Edit to add - When did Saab make planes?

Saab's first aircraft was named the Saab 17 and started to be produced by ASJA Linkoping in 1938. The bomber version was named B17 and the reconnaissance version S17.

Svenska Aeroplan Aktie Bolag

[Max_Headroom]

20 hours ago, Graham47 said:

I haven’t come across one ‘reliability’ survey that brings up “12v battery “ problems.

It may not have come up in any survey yet but if this carries on it will before long,  200 posts in the thread below here!

 

 

 

[Max_Headroom]

Quote

We know all that but it means nothing.  The forums attract owners with a problem but what you can’t quantify are the ratios. 

Ratios do not matter as we dont know how many other people have had the problem but haven't joined a forum to discuss it, one thing is for sure if you but the hybrid and dont drive it enough enough you may end up here reading this thread 

 

Quote

 Those 8 pages might includeand if you whittle them down you’ll probably find multiple quotes from the same owner - they don’t all count as separate complaint

"Might include 90% of the country’s problems" is pure speculation.

BTW I didn't say they all count as a single complaint but 200 posts in one thread must be a record here and its one of many threads on 12v Battery issues. 

 

Quote

 I don’t know why an owner should research problems -

Because if they had and they had found the thread the ones that knew they dont do enough miles to keep the 12v Battery happy may have decided not to buy the hybrid! 

 

Quote

 I don’t know why an owner should research problems - for most they are out shopping for an appliance.  

There is a bit of a difference between a £200 hoover and a £25,000 car!  😉

 

.

[Roy124]

Search just about any EV or HEV car forum, 12v batteries are a common feature. 

Thinking back, I had a Battery charger 60 years ago.  I had to replace it about 5 years ago and then buy a CTEK when I got the Corolla.  

I never had Battery problems but then I remember servicing that Battery regularly.  About once  month undo the plugs, check electrolyte levels and top up with distilled water.  Put the battery on charge, watch the gas bubbling off. 

I also used to do odd things like top up the radiator and brake fluid. 

These days the only time some people will open the bonnet is to top up the washer bottle. 

[anchorman]

I called by a mate today to show him how to use a jump pack. This quality one off Amazon was £50 and takes literally a minute to connect.  

[CruxisCore]

I was wondering where to connect the black when the leads are that short, but I guess that answers it. Manual offers a spot halfway across the bonnet where most of these small jump starters would never be long enough

[anchorman]

57 minutes ago, CruxisCore said:

I was wondering where to connect the black when the leads are that short, but I guess that answers it. Manual offers a spot halfway across the bonnet where most of these small jump starters would never be long enough

It takes very little to power up the system enough to start it - so little, the jump pack doesn’t register any power loss.  If you zoom in, the “correct” light is lit showing the strut top bolt giving sufficient earth.  

[Mikw]

So, i'm going away on holiday soon, the car will be stationary for 8 days.

Immediately before that i will be doing a couple of hour plus drives, followed by a couple of 15 minute ones, will that be enough for me to expect the car to start after so long of just sitting there?

[anchorman]

14 minutes ago, Mikw said:

So, i'm going away on holiday soon, the car will be stationary for 8 days.

Immediately before that i will be doing a couple of hour plus drives, followed by a couple of 15 minute ones, will that be enough for me to expect the car to start after so long of just sitting there?

Most people go away not even thinking about it.  If you want to cover yourself for the worst, just get one of these and you’re all sorted;

https://amzn.eu/d/edOn5GV

[Rich L-T]

I bought my new Yaris Cross in April 2022. Since then I have had two one week holidays during which time the car was kept in the garage. On both occasions I came home and the Battery was dead. Very very disappointed. We have previously owned Corollas, Corolla Verso and Yaris and they were totally reliable and NEVER let us down once. I can't believe that the new Cross which is brilliant to drive and I'm getting 68mpg on average, just can't cope with 7 days inactivity. On the first occasion the AA breakdown man told me he gets "lots of these, especially at airports." I feel like taking this up with Toyota, - anyone fancy joining me?

[FROSTYBALLS]

Similar topics merged.

[CruxisCore]

58 minutes ago, Rich L-T said:

I bought my new Yaris Cross in April 2022. Since then I have had two one week holidays during which time the car was kept in the garage. On both occasions I came home and the battery was dead. Very very disappointed. We have previously owned Corollas, Corolla Verso and Yaris and they were totally reliable and NEVER let us down once. I can't believe that the new Cross which is brilliant to drive and I'm getting 68mpg on average, just can't cope with 7 days inactivity. On the first occasion the AA breakdown man told me he gets "lots of these, especially at airports." I feel like taking this up with Toyota, - anyone fancy joining me?

New blood!

Just trying to find a pattern to these things. How is your car specced? Keyless entry? 9" Smart Connect infotainment?

How much do you drive when you are not on holidays?

But yeah, heres 30 pages of discussion on the topic. It's not uncommon, but some seem to have issues easier than others. But it could be that these people have little less of passive drain features in the car (of if they do they might have nobody waking up the system by walking past the car with keys etc) or maybe they drive so much more that the Battery remains charged.

Toyota will tell you that the car needs to be 1h in ready-mode during a week and nothing will likely come out of that. Bigger Battery will give you a little bit of leeway (so that maybe it takes 9 days instead of 7 to be empty), but if the Battery aint getting charged long enough then problems will easily ensue.

Chances are you previous Toyotas had way less tech that consumes battery even when the car is not being used. This is the challenge with modern times: i personally LOVE all these new features like the car pinging my phone i forgot to unlock the doors. But that cellular connection wont work with no battery either. I love keyless entry, but that means the car has to be half awake all the time probing if that key comes within proximity, etc. The juice just has to come from somewhere

Competitors have invented a "reset" button for the 12v battery, which gives it enough juice from the hybrid battery if needed, Toyota sadly has no such thing yet. If you look around hybrid cars in this segment, you will quickly find that these 12v issues plague most of them with certain driving habits at least. What you could do next time is manually turn off keyless entry and connected-services and whatnot before you leave for a vacation and see if that helps. Or just disconnect the battery entirely. Not that these tips make this any more acceptable, but yeah...

[Cyker]

TBH it can be mitigated - I have a suspicion a lot of the problem is due to a combination of the Battery running low during production and transport, and then subsequent low use.

I've never had an issue with mine, despite leaving it for 2 weeks over Xmas, and once leaving the sidelights on all day. However, the first thing I did with my Mk4 was go on a 2 hour hoon to get a feel for it, and I think that helped a lot - We've had some people buy the car then immediately go on a 2 week holiday, and then subsequently had a lot of trouble with the 12v, to the point where it was replaced under warranty. (And you know the battery's bad if even the dealer notices there's something wrong with it!  )

 

[CPN]

8 minutes ago, Cyker said:

TBH it can be mitigated - I have a suspicion a lot of the problem is due to a combination of the battery running low during production and transport, and then subsequent low use.

I've never had an issue with mine, despite leaving it for 2 weeks over Xmas, and once leaving the sidelights on all day. However, the first thing I did with my Mk4 was go on a 2 hour hoon to get a feel for it, and I think that helped a lot - We've had some people buy the car then immediately go on a 2 week holiday, and then subsequently had a lot of trouble with the 12v, to the point where it was replaced under warranty. (And you know the battery's bad if even the dealer notices there's something wrong with it!  )

Very similar experience with ours also...

[CruxisCore]

Mmh, good point. Especially when it's usually a month from when they finish building to actually have it ready for delivery at least here to Finland. If no one charges the Battery, it's unlikely that anyone is having it in ready mode other than when moving it around either...

I guess might stick a CTEK on mine when it comes and see what's the Battery state like at that point. Probably also gonna do that few hour test drive 😄 But might be interesting to see what the CTEK says first.

[Roy124]

4 hours ago, Rich L-T said:

I bought my new Yaris Cross in April 2022. Since then I have had two one week holidays during which time the car was kept in the garage. On both occasions I came home and the battery was dead. Very very disappointed. 

The important event was the first event.  The second flat Battery was inevitable as the first event either indicated a previous problem or caused the  problem. 

As I think Cyker pointed out, it is the driving pattern rather than the unused period that is most important. 

A succession of light usage, say 2-3 days between uses, short journey times, and you start to build up a deficit. 

The hybrid charging system does not wack the Battery in the same way a conventional alternator does. 

I found the car system gave a Battery voltage 0.25v lower than a mains charger did.

[Big_D]

We bought our Yaris and then did a 300 mile journey a couple of days after we collected it. It often gets parked for around 8 - 10 days without being used and still starts without any issues. 

At the moment, when we do use it, we travel between 6 and 15 miles at a time. There seems to be no rhyme or reason why the batteries go flat. The car has only a 380GW Dashcam fitted.

[Max_Headroom]

Quote

It often gets parked for around 8 - 10 days without being used and still starts without any issues. 

There is a big difference between often and always, the lack of use during Covid highlighted the problem so if you were to only drive every 8 to 10 days and only a short journey you too would have the same problem.