Toyota: advice on 12v battery maintenance

[PAISLEY1903]

6 hours ago, robo1 said:

Craig

The first photo shows the positive terminal with the cover in the open position. You can see there are a few grounded nuts to attach the negative clip to.

brilliant thank you very much @robo1 so any of these will do happy days thank you so much for attaching that for me. 

[dcweather]

On 3/12/2021 at 2:08 PM, robo1 said:

You could use the jump starter terminal under the bonnet. See attached photo of the Yaris manual. The multimeter would be where the battery is shown.When you get your trickle charger you will have to do this unless Mr T is putting a socket hard wired to the battery.

Can I trickle charge the auxilliary Battery from the jump start terminal here or do you have to remove back seat to access Battery directly?

[Catlover]

The Auris hybrid the wife drives has its 12v Battery in the load area and I charge that from the engine compartment as you asking.

[dcweather]

Thanks. I wonder why people are bothering taking out the back seat?

[Catlover]

3 hours ago, dcweather said:

Can I trickle charge the auxilliary battery from the jump start terminal here or do you have to remove back seat to access battery directly?

It’s best you use a slow charger, maybe you knew that.            
I bought a CTEC MSX 5. Cost £66, worth it even if you have one car, but we have two so it softened the cost.

[Fake_Empire]

I had to disconnect my 12v Battery (Corolla 2.0 l Hybrid - Battery located in the boot). I'm having trouble with tightening nut on negative terminal(I can't move it at all). The whole terminal appears to be very loose and I can disconnect it easily. I'm not sure how tight it was before. Am I doing something wrong?

[YarisHybrid2016]

I didn't read the whole thread so apologies if it's already mentioned, but the 12V Battery is only 35Ah. If your car has keyless entry as mine does, it will be low voltage inside of 3 weeks.

Running ANY car for merely 10 minutes per day will not do it any good, as nothing runs long enough to get up to operating temperature or replenish the power used to even start the vehicle (particularly true for conventional cars).

If you are a very light user, there is no replacement for either making a point of driving the vehicle for an hour or two per week, and/or using a float charger to keep the 12V Battery topped up.

On the Hybrids in particular, you can't avoid at least putting it into READY mode to ensure the HV Battery remains adequately charged.

This is even more critical on the newer Hybrids with Lithium-Ion packs as these have a higher rate of self-discharge than Ni-MH packs of the older models.

Like any piece of mechanical equipment, cars are best when driven for a long time. Very short journeys of 10 minutes, or worse, just sat around, is the worst thing for them.

Find a drive-through 50 miles away and make a journey out of it. Your car will thank you. In aviation, it's called the "$100 hamburger". 😄

[Catlover]

It has been common that during COVID and travel restrictions cars have not being used as much as previously. For example, our 2 cars have only done 2200 and 1100 miles during last 12 months. Previously doing 7000 and 4000. They are both hybrids so don’t need 12v Battery power to turn over a petrol, or worse, a Diesel engine to start. However the 12v Battery has to be strong enough to supply power to do various important tasks including kicking into action the big hybrid Battery.                
The 12v battery in a hybrid needs charging up just like any car battery. One way this can be done is by pressing the brake pedal and at the same time the Power button, that’s just as you would do if you were going out for a drive, but this time the car is going to remain stationary. The car is now in Ready mode and will show Ready on the dash. Turn off radio, air con and any other feature that will use power, even interior lights. What happens now is the hybrid battery will silently charge the 12v battery. However when the hybrid battery gets low on its gauge bars, the computer kicks in the car petrol engine to charge up the hybrid battery, which in turn keeps on charging the 12v battery. You may think this uses a lot of petrol, but it doesn’t. Leave the car in Ready mode for one hour (which will be sufficient to bring 12v battery charge up) and the petrol may only kick in 2 to 4 times in the hour, and only for reasonable amounts of time. If when you do thi there are a lot of bars on the hybrid battery gauge will mean the petrol engine only kicks in a couple of times in the hour.                        
Now we have more freedom to travel the cars will start to be used more. That will have good effects on the whole of the car ie tyres will be revolving, seals will be lubricated, lots of little but positive things. And of course we can get out and enjoy the countryside and visit people and places.          
During this charging process, do make sure the car is left unattended, especially if it by the roadside, or even on the drive. It is in Ready mode, that is ready to be driven away by persons other then you.         
As said in previous post, driving down to the shops 10 min each way is not doing the 12v battery any good. It needs more.             
Another way of charging the 12v battery is to use a slow battery charger. These latest battery chargers are designed to keep a healthy 12v battery healthy, and help along weaker ones. I, personally can recommend a CTEK 5 to do a good job. It may cost just under £70 new, but it’s an investment that should pay back over the years you have it.  

[Grompix]

Is there any way of turning off the Daytime running lights when charging the 12v Battery with the car in 'READY' mode?
I've managed to turn off the climate controls, interior lights and infotainment system but the front daytime running lights remain on (and the rear lights too inexplicably).
Just can't figure out how to turn these things off.
Thanks
Chris 😉  

[FROSTYBALLS]

No, DRL's are a legal requirement. On some cars the DRL's don't illuminate until the handbrake is released, but the car may not have this feature.

[Grompix]

4 minutes ago, FROSTYBALLS said:

No.

Don't beat about the bush Mike.
You need to keep your answer straight, succinct and to the point!
😁 👍

[FROSTYBALLS]

My reply has since been edited.

[Cyker]

On my Mk4, the DRLs do not turn on until the car is shifted out of P, then they are permanently on until the car is turned off or headlights are turned on.

I usually turn the car off then on again (To Ready mode) if I'm parked, just so the DRLs stay off - Should work for you too since yours is also a Mk4!

 

[Yugguy1970]

LEDs don't draw much current so I wouldn't worry.  If leaving on the drive in ready you'll get far more benefit turning off the climate.

[Cyker]

For me it's not so much the power draw, but more courtesy - With them on you're potentially distracting other drivers, as they may think you're going to move, or blinding them, especially at dusk (Rant: I still despise DRLs as nobody uses their sidelights, so when it starts to get dark, esp. in winter, I'm having my eyeballs burned out by streams of sun-bright DRLs from the opposite lane of traffic. I'm still of the opinion DRLs don't improve safety as much as 'they' say. If anything they make it worse - It's now impossible to spot cyclists and bikers filtering from behind in your peripheral vision, because they are masked by a sea of DRLs! And when it gets darker, your eyes are compensating for the DRL brightness, so anything that isn't equipped with DRLs becomes harder to see, e.g. cyclists, scooters, pedestrians, animals).

 

 

[Grompix]

3 hours ago, Cyker said:

On my Mk4, the DRLs do not turn on until the car is shifted out of P, then they are permanently on until the car is turned off or headlights are turned on.

I usually turn the car off then on again (To Ready mode) if I'm parked, just so the DRLs stay off - Should work for you too since yours is also a Mk4!

Wow thanks Cyker, that worked perfectly!
Turned on the car to 'READY' mode - DRLs still on. Turned the car off then back to 'READY' mode again - DRL's off. Bingo!
Infotainment system off (or at least blanked the screen - which I assume is 'off') and climate controls off, everything off inside the car - except...
...the passenger footwell lights which I installed a couple of weeks ago on the original Toyota wiring harness. They stay on - no matter what. 
But I can live with that.
Just wasn't too happy with the car lit up like a Christmas tree on the drive while charging the 12v Battery!
Strange car this Mk4 Yaris 🙄  
Thanks again Cyker 😊👍    

[Cyker]

Glad to help!

[Grompix]

This could amount to (hopefully) nothing more than another one of my paranoid suspicions over the dealership that sold me my 2020 Yaris Excel.

Having read on this forum just how prone to failure the 12v auxiliary batteries are on hybrid cars in particular (reading too much could account for my increased concern of course!) but I suspect I may have a duff 12v Battery - or at least one that is on its way out.

I wonder if members on this forum would be kind enough could give me their opinion on the following observations I’ve made on my 12v Battery voltage states over the last week or so.

Listening to my multimedia in accessory ‘mode’ (power drawing purely from the 12v battery), I get a message within a few minutes, warning against using the unit without the engine running. This is the similar to the report that ‘FrostyBalls’ mentioned on Feb 6th 2021 with his Hyundai i20.

I have one of those 12v Lighter Socket ‘thingies’ that displays the Battery state of the car (see pics). The voltage of the battery shows 12.6v after charging for an hour or more with the car standing in ‘READY’ mode but quickly drops to 11.9v after using the multimedia for a few minutes.

Similarly, in ‘READY’ mode and driving (with the traction battery also supplying a charge), the battery never gets above 13.7v. I would have assumed that a healthy 12v battery would show 14+v at this point.

The Battery voltage also drops to 11.9v with the car in Ignition mode too (see pic).

As an additional entry to the growing list of incompetencies I am still discovering, I would not be surprised if Birmingham Toyota had also let the battery go flat at some stage during their ‘careful’ ownership of the car.

Any thoughts chaps?    

Chris 🙂  

[TonyHSD]

Just don’t use accessories mode and alway keep the car in ready mode while seated in and use anything like radio, infotainment or charging your phone. The message you get is as preventative measure to stop you doing exactly that, and the car should also switch off automatically all consumables in an hour time or less, but if you do this on regular basis will kill 12v Battery. If the car get regular use for half an hour or more at a time you will be ok with your Battery long time, I am still fine with my original Battery even after 11 years. 👍

[Grompix]

On 8/26/2021 at 9:51 PM, TonyHSD said:

Just don’t use accessories mode and alway keep the car in ready mode while seated in and use anything like radio, infotainment or charging your phone. The message you get is as preventative measure to stop you doing exactly that, and the car should also switch off automatically all consumables in an hour time or less, but if you do this on regular basis will kill 12v battery. If the car get regular use for half an hour or more at a time you will be ok with your battery long time, I am still fine with my original battery even after 11 years. 👍

Thanks Tony 👍
...but I find this whole 12v Battery thing pretty perplexing.
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?

To be advised (especially if you are a low mileage user) that you must regularly place your modern (and extremely expensive) car in ‘READY’ mode to keep the 12v battery from discharging completely (or charge with an external charger) is gob-smacking to say the least. It’s the kind of thing you would do with an old banger with a battery on its way out (been there, done that, got the ‘T’ Shirt), not with an up-to-date, often cutting-edge, technologically advanced vehicle.

My old 2014 Mk3 Yaris hybrid never shouted at me to shut off or start the engine after 5 minutes of multimedia playing either - 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. Yaris works totally reliably without any issues at all. So, assuming that the 12 volt batteries are the same in all Yaris hybrids, what has happened with the newer cars and why?
Perplexed.
Chris 😞

 

[TonyHSD]

10 minutes ago, Grompix said:

Thanks Tony 👍
...but I find this whole 12v battery thing pretty perplexing.
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?

To be advised (especially if you are a low mileage user) that you must regularly place your modern (and extremely expensive) car in ‘READY’ mode to keep the 12v battery from discharging completely (or charge with an external charger) is gob-smacking to say the least. It’s the kind of thing you would do with an old banger with a battery on its way out (been there, done that, got the ‘T’ Shirt), not with an up-to-date, often cutting-edge, technologically advanced vehicle.

My old 2014 Mk3 Yaris hybrid never shouted at me to shut off or start the engine after 5 minutes of multimedia playing either - 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. Yaris works totally reliably without any issues at all. So, assuming that the 12 volt batteries are the same in all Yaris hybrids, what has happened with the newer cars and why?
Perplexed.
Chris 😞

 

You are right about it, perhaps the latest models has some sort of connected service like sos and life data transmission to Toyota servers. Not sure exactly as I am an old school hybrid owner and my one hasn’t got even an info screen, still on its original Battery, no complain here although I had the Battery warning message on the dashboard once or twice 👍

[IanML]

On 8/26/2021 at 8:00 PM, Grompix said:

I have one of those 12v Lighter Socket ‘thingies’ that displays the battery state of the car (see pics). The voltage of the battery shows 12.6v after charging for an hour or more with the car standing in ‘READY’ mode but quickly drops to 11.9v after using the multimedia for a few minutes.

Similarly, in ‘READY’ mode and driving (with the traction battery also supplying a charge), the battery never gets above 13.7v. I would have assumed that a healthy 12v battery would show 14+v at this point.

The Battery voltage also drops to 11.9v with the car in Ignition mode too (see pic).

 

Replying to the specific questions above, not as a hybrid owner, but as an electrical engineer:

The charging voltage is untypically low, as is the value after a few minutes on load.  There are three possibilities- (1)The meter is reading low, so verify these values with a decent quality multimeter, (2) the Battery is below par/defective, so disconnect it and charge it with a trickle charger, and then recheck the above voltages, or have it checked at a Battery outlet (not a Toyota dealer), and (3) the car's dc/dc converter is defective and is outputting too low a voltage - this needs to be checked by reference to the Toyota diagnostic information, so, if (1) and (2) are ok, take the car to a Toyota dealer, insist on speaking to the diagnostician and give him the information, to convince him that the dc/dc converter needs to be checked.

Regarding the second question, the value you see is largely dependent on the output of the dc/dc converter, not the Battery, so the diagnostic test will address that.  The 3rd question suggests the dc/dc converter again, but subject to validation of your meter, as above.

I hope that helps.

[robo1]

Regarding the accuracy of the USB meter I bought a similar meter to give me some idea of the state of charge of the 12v Battery. I checked it’s accuracy against a multimeter and it was reading 0.3v low.

[Grompix]

10 hours ago, IanML said:

Replying to the specific questions above, not as a hybrid owner, but as an electrical engineer:

The charging voltage is untypically low, as is the value after a few minutes on load.  There are three possibilities- (1)The meter is reading low, so verify these values with a decent quality multimeter, (2) the battery is below par/defective, so disconnect it and charge it with a trickle charger, and then recheck the above voltages, or have it checked at a battery outlet (not a Toyota dealer), and (3) the car's dc/dc converter is defective and is outputting too low a voltage 

Thanks for your feedback Ian and Keith.
Playing on my suspicions (paranoia!), I decided to take the advice purveyed on this forum and last week purchased a CTEK MX5 charger. Bit pricey but my partner's Golf is also appears to be exhibiting Battery symptoms. She's owned the car for over 10 years from new with no Battery change so her battery is very likely on it's way out.
The CTEK purports to help revive and rejuvinate ailing batteries so I thought  the purchase  might be a good investment. 
Three days ago I connected my Battery to the CTEK through the Yaris under-bonnet jump-start/charging connections, chose the AGM cycle and left it to do its stuff overnight. The next day, the CTEK reported no problems but ever since then my battery has exhibited readings much more like a healthy battery should (see attached pics). Full marks for CTEK.
Need to try it on my partner's Golf now.
You'll see I have tested the 'JEBSON'S' USB car-voltage against my old multimeter, and they seem near enough.
I'll keep a close watch on my battery voltage to see if it declines in any way.
Thanks again chaps.
Chris 😊👍          

[IanML]

That all sounds pretty good, although I am surprised that the low Battery could drag the 14.2V down to 13.7.  That could just be a high resistance connection somewhere in the wiring, rather than a fault in the converter.

I'd be interested to hear whether it will keep things up to the mark in the future, or whether you will have to bring out the trickle charger again.