12v battery maintenance, issues, etc.

[Max_Headroom]

20 hours ago, Graham47 said:

They aren’t !
Mine has been left for 5 weeks (twice) and 3 weeks (twice) without issue.  I don’t have access to charging nor do I possess a solar charger.

 I suspect many of the ‘fears’ you highlight in your post are as a result of (new) owners reading this thread !!

The thread is 8 pages long and there are many examples of owners leaving their cars for a few days then having problems its obvious if you drive often enough you will have no issues but i bet the sales men/women don't mention this when they are selling you the car, i leave my second car parked up weeks at a time and it never fails to start this really should have been sorted when it became apparent it was an issue.

[Roy124]

Max, indeed.  When I retired I laid my Escort Cabriolet up for some months. Come late Spring it would not go. 

Started OK but the handbrake was rusted on. 😅

[Roy124]

As matter of interest I just checked my YC.  The voltmeter gave 12.8v (it was driven yesterday).  I plugged in the CTEK anyway and the AGM steps 1 and 2 came on immediately.  Step 2 is increase the BV to 12.6.

Almost immediately after step 3 came on which is increase to 14.5v.

Once it has run through the steps it will allow the voltage to decay and then boost.  Too cold to stand out and wait. 

[Max_Headroom]

3 hours ago, Roy124 said:

Max, indeed.  When I retired I laid my Escort Cabriolet up for some months. Come late Spring it would not go. 

Started OK but the handbrake was rusted on. 😅

You mean you forgot to put bricks under the wheels and leave it in gear with the handbrake off  😉 

[Roy124]

15 minutes ago, Max_Headroom said:

You mean you forgot to put bricks under the wheels and leave it in gear with the handbrake off  😉 

Quite.  Never occurred to me as it was in my garage and I had never laid up a car before. 

Many years ago I did have to leave my Ford Anglia for 3 months.  It was left on a hangar as and I only had time to reclaim road tax and change the insurance. When I went back it was simply a question of starting and driving off.  I don't (60 years on) remember checking tyres etc.  The car was only 6 month old and I had no experience. 

 

[AisinW]

On 12/11/2022 at 4:06 PM, Roy124 said:

As matter of interest I just checked my YC.  The voltmeter gave 12.8v (it was driven yesterday).  I plugged in the CTEK anyway and the AGM steps 1 and 2 came on immediately.  Step 2 is increase the BV to 12.6.

Almost immediately after step 3 came on which is increase to 14.5v.

Once it has run through the steps it will allow the voltage to decay and then boost.  Too cold to stand out and wait. 

Most Smart Charger (CTEK, LIDL, ALDI, NOCO5, Bosch, etc.) have many steps of charging and the cutoff is usually pretty high about 14.5-15V.  Basically, it charge until full but the float voltage of the Battery after surface charge is removed (headlights on for 1 minute), the open circuit voltage is usually about 12.5-13V in good working AGM Battery.  The problem shows up more clearly when we put a load on it.  So, you can turn the heater seat ON, blower motor at max and headlights on for 15 seconds and read the voltage reading. It should be more than 10V for a good Battery. Typically the voltage of the battery with the Ignition ON/ ACC mode (2x pressing power button without pressing brake pedal) for normal battery is 11-12 V after we fully charge the battery.  Below 11V in ACC mode means the battery is at the end of its life. 

[RobertR]

Watch this video and you wii everything about the 12v Battery in your hybrid. https://youtu.be/_V9PiOpaxyE

[Tonanti216]

I have a 2021 model and have exactly the same problem as Joby1 - 

I don't use the car every day but on many occasions, particularly during lockdown etc. the car did not get moved.  

It seems odd to me that I am the one to blame for not "keeping the Battery charged up"  if you have to jump start it and then leave it on charge overnight so that you can be sure it'll start every time.  I'm starting to question my judgement when I decided to upgrade my old 2012 Yaris, so faithful and sturdy for this temperamental "new kid on the block"!

[Roy124]

Richard, agree it is a problem. While Toyota's advice is sound it is not always practicable.  Airport parking is an obvious instance.  Involuntary laying up is another. 

If you are ill you are not wanting to go out and run the car.  Indeed if you rely on on street parking it is impracticable. 

Every time we have issues we should thump Toyota and call the dealer.  In my case the dealer fitted a Battery with 20% greater capacity.  Larger capacity batteries with the same volume are available. 

[Cyker]

TBH all they need to really do is put in a cut out like Hyundai/Kia do.

It's one area I'm surprised they've allowed to remain a problem for so long, as this has been an known issue for over a decade! I can only think they don't consider it a problem for them to fix, and more 'user error' or something.

 

[ToyotaGal33]

This has happened to my new Yaris Cross 3 times in the last couple of months now after short periods of not using the car in the colder weather. On this latest occasion, the car had only gone 3 days without being used and the Battery was down to 8v and couldn’t turn anything electrical on, including initiating the high voltage Battery to start the car.

In my view, possible issues could be:

- the 12v Battery in my car is faulty

- the 12v battery installed by the manufacturer is too small for the draw of the electrics on start up (there are a lot of new features on the Cross that older models didn’t have)

- the electrics on my car are incorrectly drawing too much power from the battery on start up. 

I have not heard of this issue with larger Toyota models such as the RAV4, as they obviously have larger capacity batteries installed and the electrics are not yet the latest spec meaning the draw will be less on start up. Being a new model though, I wonder if anyone else is having the same issue with their Yaris Cross? Or even the Yaris or CH-R?

The dealer I purchased my car from is going to do a battery draw test, however I’m not sure there is a long term solution other than a solar powered trickle charger, which, aside from the cost, doesn’t seem like the most reliable “solution” in the UK winter! At the moment it seems like a certainty that should I go away for a couple of weeks for work or holidays, the car will be to totally flat when I get back - I certainly couldn’t leave it in an airport car park and be able to drive home on my return!

Is anyone else experiencing this issue, especially if they don’t commute daily using their Yaris Cross?

Thanks all!  

[Mojo1010]

8v is no good obviously. Even bringing it back with trickle charger it has an effect already going that low. Only way is to change the Battery for a new one, which they should do it under warranty. 

Either the Battery is no good to start or didn't get use much during this winter. My yaris is 6.5 years old no problem with 12v Battery. Using 2x a per week for 30mins each I find it enough to cope with the winter. 

Anyway wait and see what the dealer say after their test and let us know. 

[RobertR]

If your 12V Battery won't last even 3 days of not using the car, it is damaged for sure, contact the dealer and ask for a replacement. Every other explanation is very unlikely.

We have a thread here where customers reporting this problem with discharging the 12V Battery but it's a matter of weeks, not days, there are people here that are reporting 2 or more weeks of inactivity without the problem.

Generally, hybrid cars have issues with discharging 12V batteries at a higher rate than nonhybrid cars but not this high.

[Baytree]

2 hours ago, ToyotaGal33 said:

This has he experiencing this issue, especially if they don’t commute daily using their Yaris Cross?

Not so far with an Excel and the SmartConnect system. I assume its cellular connection is using charge all the while as it broadcasts its status and waits to be unlocked.

What model do you have?

[ToyotaGal33]

I think actually this must be the 4th time it’s happened to me thinking about it. The first time was on getting home from a 10 day holiday, the next after 7 days of inactivity, the next was about 5 days and the most recent, this Sunday was only 3 days, so it’s definitely getting worse, especially during colder weather! 
 

Definitely want the dealer to replace the 12v Battery now but they’re also going to check the draw on the Battery. As to me there are just too many electrical systems trying to start up from the 12v, when the majority of that power should be used to get the high voltage Battery going to start the car! Everything else can come on after that as far as I’m concerned 😂

I’ve got an Excel too @Baytree. 👍

[Mojo1010]

I have been away in sept and Oct for 8 & 9 days, started no problem on return. As I'm probably going to be away for 8-10 days in Jan/Feb next year, I was a bit concern of winter as not gone that long ever in winter without using the car. So I asked forum members, some have been left for 2 weeks and no start problem in the winter. 

The problem you are having, it's a lot of grief. Let see what your dealer say first. 

[flash22]

There is a recent TSB for the DCM not turning off, i did post it on here

the cold snap lately is enough to kill off a weak Battery

22SMD-117-CT

 

[philip42h]

5 hours ago, ToyotaGal33 said:

I have not heard of this issue with larger Toyota models such as the RAV4

Pop over to the RAV4 section - there are plenty of similar issues reported though, generally it is not a problem. 🙂

The auxiliary Battery on the RAV is a mere 45Ah - I doubt that the Yaris / Yaris Cross is smaller?

Either your Battery has an issue (and the dealer will be able to find / sort that) or there is is an accessory draining the Battery when the ignition is Off (i.e. connected in to the 'wrong' side) or, maybe, you are using Accessory mode too long / too often (that's a 'good' way to drain the auxiliary battery). 😉

[Vainona70]

Toyotagal33 - you don't seem to mention the miles & types of journeys you are doing. Multiple short journeys will kill the Battery, so you'll need to sit in the car whilst in Ready mode for 40 minutes a week so the traction Battery can charge the 12v Battery. This seems counter intuitive for someone new to hybrids, but it's worked for my wife's Yaris. 

Issues of this sort with the mk4 (latest) Yaris are well documented in this section of the forum.

[Mojo1010]

34 minutes ago, philip42h said:

Pop over to the RAV4 section - there are plenty of similar issues reported though, generally it is not a problem. 🙂

The auxiliary battery on the RAV is a mere 45Ah - I doubt that the Yaris / Yaris Cross is smaller?

Either your battery has an issue (and the dealer will be able to find / sort that) or there is is an accessory draining the battery when the ignition is Off (i.e. connected in to the 'wrong' side) or, maybe, you are using Accessory mode too long / too often (that's a 'good' way to drain the auxiliary battery). 😉

Yaris MK3 it's 35Ah

[MikeSh]

3 hours ago, ToyotaGal33 said:

The first time was on getting home from a 10 day holiday, the next after 7 days of inactivity, the next was about 5 days and the most recent, this Sunday was only 3 days, so it’s definitely getting worse, especially during colder weather! 

This is to be expected. Deep discharge damages the Battery somewhat (usually one or two cells in practice), so it will get worse each time it happens.

At this stage it's basically toast, but the root cause of the discharge, such as in flash22's post above, needs sorting or it will likely keep happening to a new Battery.

[Roy124]

My Cross was a month old, left for 12 days though moved short distances by the car park people.  No issues. 

Certainly had issues with a MY19 Corolla 

[philip42h]

1 hour ago, Mojo1010 said:

Yaris MK3 it's 35Ah

so LN0 ... according to the Owner's Manual the Yaris Cross is LN1 (45Ah) or LN2 (51Ah) - exactly the same as the RAV4 HEV and PHEV respectively ... 😉

[philip42h]

7 hours ago, ToyotaGal33 said:

I certainly couldn’t leave it in an airport car park and be able to drive home on my return!

The work round for that problem is to carry a charged Li-ion jump start pack in the car. If you are leaving the car for 'days' you shouldn't need one but if leaving the car for 'weeks' it may save calling out the breakdown folk. Something like the NOCO Boost Sport GB20 is more than enough to get our hybrids into Ready mode ...

[flash22]

Mk4 uses a calcium Battery, one step up from a lead acid, Mk3 uses an AGM, they use 2 very different charging systems

There is nothing to say that the Battery was faulty from new