Toyota: advice on 12v battery maintenance

[Cyker]

I hope that smart charging thing isn't for standard automotive 12v batteries (I've only seen the kind of mild-hybrid regen-braking thing for cars with higher voltage batteries, e.g. 48v.)

A normal 12v lead acid Battery, esp. starter batteries for cars, really don't like being left at partial charge - They much prefer being kept at 100% or as close as possible, or they start to degrade faster than they normally would.

Lithium on the other hand doesn't like being held at extremes of charge (i.e. 0% or 100%); It likes to be about 50-60% for maximum longevity.

 

[Dala]

Smart charging and start-stop systems require a Battery with modern technology, because normal starter batteries are not designed to meet the higher demands of these vehicles.

Quality batteries for smart charging and system start-stop are AGM - Absorbent glass mat. Batteries differ from flooded lead–acid batteries in that the electrolyte is held in the glass mats, as opposed to freely flooding the plates. Batteries are more resistant to self discharging than conventional batteries.

 In a car which is not equipped with an automatic start-stop system, the starting process is usually a one-off event. 

The case is different for cars with start-stop technology. During a journey through the town, the Battery is subjected to a series of start and stop periods. If the car is stationary at traffic lights with the engine stopped, electrical consumers such as lights, windshield wipers, radio or displays still need power. The load is increased by continuous discharge and charging.

The architecture of the electrical system in modern vehicles requires a compatible Battery technology in order to function properly and reliably. For this reason, in many vehicles, new batteries must be “registered” – the Battery Management System (BMS) must know what type of battery is installed in the vehicle in order to exploit its full potential. If an incorrect battery is installed in the vehicle or is not correctly registered, this can result in premature battery deterioration and another breakdown.
 
For this reason, only EFB or AGM batteries should be installed in vehicles with automatic stop-start systems. If an AGM battery is already installed in the vehicle, it must always be replaced with another AGM battery.

 

[IanML]

If anyone is thinking of trying a Li-ion 12v Battery, this link is to such a replacement in a KIA SoulEV.  The owner is very happy with it.

[Dala]

or wait, the future offers solutions: GAC charges in 8 minutes

[Dala]

professional solution to the car Battery problem from a toyota dealer 🙂

mag.toyota.co.uk

 

[PAISLEY1903]

@robo1 Coming back to you late on this!  Just got car last week and remembered our discussion.

Below is my box, the right side of it has that mirror effect with other side just plain plastic.  When attaching the leads are you putting it just over the top gripping plastic and metal or at edge again gripping plastic and metal.  Sorry for being dim!  Never done it in my puff.. hope never have to but just like to be prepared!

[Catlover]

Hi Craig, I assume you will have a red and a black crocodile clips. Using the red croc clip on the stub shown grip it over the metal terminal. The black will grip onto some earthing tag somewhere near.

[PAISLEY1903]

2 hours ago, Catlover said:

Hi Craig, I assume you will have a red and a black crocodile clips. Using the red croc clip on the stub shown grip it over the metal terminal. The black will grip onto some earthing tag somewhere near.

Thanks Joe, so basically grip it onto it with the red grip and as long as one half of the grip is on the metal bit all good (as opposite side is plastic) thank you very much.  I will put the black onto the big nuts! (not mine!)

[Catlover]

Ah right, I couldn’t see the other side of the metal is plastic. So yes, get the best connection you can.

[Grompix]

1 hour ago, PAISLEY1903 said:

Thanks Joe, so basically grip it onto it with the red grip and as long as one half of the grip is on the metal bit all good (as opposite side is plastic) thank you very much.  I will put the black onto the big nuts! (not mine!)

 

59 minutes ago, Catlover said:

Ah right, I couldn’t see the other side of the metal is plastic. So yes, get the best connection you can.

Yep, as Catlover says, that should do it. I did basically the same thing myself - no problems at all. 

[PAISLEY1903]

8 minutes ago, Grompix said:

 

Yep, as Catlover says, that should do it. I did basically the same thing myself - no problems at all. 

Thank you very much 

[Grompix]

On 9/5/2021 at 9:46 AM, Grompix said:

Many thanks for taking the time and trouble to air your opinions / experiences here chaps. All very interesting (and useful).
My Yaris is still dropping from 14.2v to 13.1 v when in 'READY' mode or driving. I'm waiting to see if it drops further.
If it does not then it might point to the effect of 'smart' charging rather than a defective battery.

Four plus months on and a review of the 12v Battery condition / performance in my Yaris Hybrid.
It regularly starts showing 14.2v and after a variable amount of time (a few minutes to half an our or so) it will drop to 13.1v and mostly stay that way. Sometimes rising to 14+ volts again but never going below 13.1.
That indicates to me that it is in fact behaving 'normally' and probably (as 'Dala' pointed out in an earlier post) that the car is 'smart' charging. 
All this is quite different to the behaviour of my 12v Battery before I hooked up the CTEK charger so it seems that investment has paid off somewhat.
However, I don't use the infotainment system In 'accessory' mode anymore. 
Why Toyota did not just program one of the car's ICUs to automatically top up the 12v Battery from the big traction battery when in accessory mode instead of a 'TURN OFF YOUR IGNITION!" warning message certainly puzzles me. There must be a reason but it escapes me for the moment.
So I use the infotainment system in 'READY' mode - which overcomes the above problem.
As the weather gets colder - I'll see if my 12v battery continues to behave itself.        

[Cyker]

Yeah, it's like why they have a neutral despite the fact that the HSD can't actually go into neutral (In normal cars, neutral=disengage the drivetrain, but this is physically impossible on HSDs and EVs)

I assume it's due to archaic laws/rules that haven't been updated for modern times that say it has to this way or have this thing for the car to be homologated.

It's like how the WLTP has just been ratified to stop things like ICE mpg figures being so far off reality, but in the time it's taken them to do that PHEVs and EVs have appeared and have taken over the problem they had with ICE figures on the old system! (It's great how we had unachievable ICE mpg figures on the old system, and now we have unachievable EV range figures on the new system  )

Always a step behind...

 

[robo1]

On 9/27/2021 at 3:36 PM, PAISLEY1903 said:

Coming back to you late on this!  Just got car last week and remembered our discussion.

Sorry for not replying sooner but the notification of a new comment went to my junk mail. Glad your question has been answered. Did read somewhere that ideally you should put the side of the crocodile clip with the lead attached on the metal side of the terminal to maximise current flow. 

[PAISLEY1903]

On 9/29/2021 at 9:39 AM, robo1 said:

Sorry for not replying sooner but the notification of a new comment went to my junk mail. Glad your question has been answered. Did read somewhere that ideally you should put the side of the crocodile clip with the lead attached on the metal side of the terminal to maximise current flow. 

cheers @robo1 good shout !

[tom3treu]

Hmmm... followed threads with interest. I am currently in the market for a new car and the Yaris Hybrid( 2014-2020)caught my eye (economy/ease of driving/quietness-in town or when running on EV/reliability).  I am a low mileage driver (3-4k a year)would use the car usually once/twice a week for short journeys, and a few longer trips ( including one 700 mile return journey; the annual trip to the South coast.) Would I likely face similar problems as per previous posters ?

Thank you for your time

[Grompix]

1 hour ago, tom3treu said:

Hmmm... followed threads with interest. I am currently in the market for a new car and the Yaris Hybrid( 2014-2020)caught my eye (economy/ease of driving/quietness-in town or when running on EV/reliability).  I am a low mileage driver (3-4k a year)would use the car usually once/twice a week for short journeys, and a few longer trips ( including one 700 mile return journey; the annual trip to the South coast.) Would I likely face similar problems as per previous posters ?

Thank you for your time

Since you mention that you are interested in a Yaris Mk3 (2014 -2020), I can only repeat what I have already said here.  Not once in the nearly seven years I owned my last car, a 2014 Toyota Yaris Hybrid Excel Mk 3, did I experience an single issue from the 12 volt Battery. Come to think of it, I never experienced any issue at all (apart from one slow puncture). That car performed superbly and totally reliably from day one of ownership. And my journeys were nearly always short (only 37000 on the clock after it was ‘totalled’). It was driven through some of the worst weather that this UK can throw at us and that car spent most of its life out on the driveway too, not mollycoddled in a nice warm garage.      

I find the whole 12 volt auxiliary Battery vulnerability ‘issue’ for the newer hybrids (and some standard petrol cars too it seems) more than a little irritating (another 'niggle' for the list!). It appears reliability has been sacrificed by the manufacturer for for - what? I don’t know. Cost-cutting perhaps?

My old 2014 Mk3 Yaris hybrid never shouted at me to shut off or start the engine after 5 minutes of multimedia playing - but my newer Mk4 does. And it appears that this is not unique by the comments I read on this forum.

I never needed to charge the 12v Battery in my Mk3 (in ‘READY’ mode or otherwise).

Some might say that the newer vehicles have more electronics than the older ones, which puts more workload on the 12v battery. Well, a friend has a 2017 Mk3 Yaris Excel and that car has speed-sign recognition, keyless entry, lane assist, and a lot of the other systems that are fitted in my Mk4 Yaris (but not the radar ones). She has no probs with the 12v battery - never has. Long journeys or short, bad weather or good, car standing for weeks or not. Her Yaris works totally reliably without any issues at all.

I'm left with the impression that the Mk3 Yaris is/was a lot more reliable (at least 12v auxiliary battery-wise) than the current Mk4.

[Nick72]

Just got back from international business trip and I'd not started the car for 10 or 12 days. Was expecting a problem but it started no problem. Will see how I get on in December when it is cold and I'm away for over 2 weeks.

RAV4 PHEV.

[Yugguy1970]

Like I said in another thread our Yaris will be left alone for 2 or maybe 3 weeks.  I expect no problems at all.

[AisinW]

Just Want to share the voltage reading of my 2015 Auris Touring Sport Hybrid at 5C.  Open Circuit with Voltmeter shows 12.3 V but the OBD2 scanner cannot read it.  So I press the power button 2x, ignition is on and Voltage from CARISTA with Torque-Pro Apps (loaded with Prius gen3 profile) shows exactly the same as my voltmeter 11.9V.   Turn the headlight ON it shows 11.4V.   At max possible loads: defroster front and back, Blower Motor at Max, head lights are ON and it still shows 10.9V.      

Although it is almost 6 years old, the Yuasa Toyota Battery are still in excellent condition.  One of the reasons is mild weather in west Europe and summer is not that hot. I remember my 2006 Prius Battery died in 2014 (7+Y) in hot Florida weather without any garage shows 10.9V when ignition was on. It drops close to 9V when the headlight is on and often I cannot even unlock the door.  New Battery from Yellow top Optima battery shows between 11.9-12.1V when ignition is ON and have very similar reading as I have now. 

The hybrid voltage is virtually identical in all cells once it is in READY mode. The internal resistance is way too low and only with Dr.Prius I could read them accurately.  Only about 1 mOhm different.  I wonder why UK/Ireland has 15 years warranty on hybrid battery now.  Probably of cloudy and rainy weather makes the battery last longer. 

[Dr Gunsmith]

I’m needing a new 12 volt Battery, as the one in the second hand Prius I bought looks old, it’s a aftermarket one so I’m unsure what I exactly need because all the writing is unreadable, should I buy a genuine Toyota or is there any better alternatives. Thanks.

[IanML]

Toyota batteries are good quality, but you can get the same quality for quite a bit less.  I recommend Yuasa.  If you are careful not to run them down flat, they can last 6 or 7 years.

Its worth shopping around - there can be a lot of price variation.  I've found the best price can be mail order via eBay last time I was looking.

[Catlover]

A lot of Toyotas, particularly the hybrids have Yuasa as standard.  3.5 years I bought a new Battery for our Auris hybrid from TAYNA (Battery specialist in north Wales). I found out afterwards Toyota dealer was the same price. So when shopping around it is always worth asking your Toyota dealer. Same experience with tyres, Toyota dealer price as good as anywhere else.

[Dr Gunsmith]

Thanks folks for the great information 🙏

[Tee_J]

Hi all,

New to this site having purchased a Toyota Estima (2008).

Recently, my auxiliary 12V Battery went kaput!  The cause? Sitting unused for extended periods of time. 😞 I went on a search and chanced across this site, and via the Estima forum, found the part number and was able to purchase a new Battery (£210!!) from a local Lexus parts store.

My question: is it possible that I could have used the device recommended a few time under this thread - CTEK 5 - to get that previous Battery into good health?
It's a bit late for me obvs, but that could help someone else with the same issue. 😉 That is why I am posting my comment.

Cheers!