12v battery maintenance, issues, etc.

[50p]

1 hour ago, Mr Billiards said:

When you use the Ctek via the + in the fuse box terminal under the bonnet , where do you connect the negative lead to.

Any earth connection or a convenient part of engine, NOT the -ve Battery terminal as it can mess up the electronics.

[DC_Ms]

4 hours ago, Mr Billiards said:

Thanks for that, much appreciated. I will give it a try next time I wash the car and leave it in ready mode for an hour.

I have the car for 6 months now , I do valet my car inside and out … so I do really take my time with cleaning the car … but so far I have never put the car in Ready mode … and so far so good. The car is driven though every single day , long hours continuously 

[Elmahdi]

On 3/10/2022 at 12:41 PM, Spo2 said:

Call me naive but is there any harm if the battery is discharged? When you come back, start with a portable jump starter, drive amd you should be fine? 

I had the same problem after two weeks off. I had to jump start the 12v Battery located in the back that’s all.

[TrackLink]

I’m planning to connect the 12V Battery of my 1.8 Corolla to a smart charger once every 2-3 weeks to keep the Battery in a healthy state of charge. Having read through this thread I’m not 100% clear whether I’m OK connecting the negative croc clip from my smart charger to the negative terminal on the Battery though. Would appreciate confirmation that this is or isn’t OK to do!

[Cyker]

It would be better if you had some proper leads - the big crocodile clips used for jump-starting are not really suitable for connecting to trickle-charge a Battery long term in a car, as they can slip off easily and touch things you really don't want them touching.

Other than that, it would work though.

Note that you only need to do this if you basically don't drive the car.

If you actually use it for stuff regularly, it shouldn't need extra charging.

[Geoff W]

I took my car in for it's annual service on Friday and was interested to see on the service reception desk a prominent display for a solar powered Battery top up device with a poster saying that "modern cars still use electricity when they are not being driven". Toyota apparently admitting there's a problem with the Battery capacity?

£50 if you're interested!

  

[Roy124]

38 minutes ago, Geoff W said:

a solar powered battery top up device with a poster 

  

But you're jiggered if you have a garage or you park under cover 🤔 

[Geoff W]

And, disappointingly, it came with big crocodile clips - not something you could just plug in to one of the car's sockets. But are any of the sockets live anyway when the car is parked?

[TrackLink]

13 hours ago, Cyker said:

It would be better if you had some proper leads - the big crocodile clips used for jump-starting are not really suitable for connecting to trickle-charge a battery long term in a car, as they can slip off easily and touch things you really don't want them touching.

Other than that, it would work though.

Note that you only need to do this if you basically don't drive the car.

If you actually use it for stuff regularly, it shouldn't need extra charging.

Thanks Cyker. My smart charger came with O-ring connectors which can be permanently connected to the Battery terminals. Unfortunately I forgot to remove these connectors from the Battery of my previous car before selling it to Toyota as part exchange for my new Corolla 🤪. The charger also comes with compact croc clip connectors so I’ll need to use those. The Corolla will be doing about three 30-minute journeys a week and longer weekend journeys (1-2 hours) approx. twice a month, so perhaps that will be enough to keep the 12V Battery in a healthy state without topping up via the smart charger.

[Sergus]

Has somebody tried Defa onboard charger, like 1205 or 1210 flex?

[Fake_Empire]

Hi all,

Corolla TS 2.0 Hybrid 2020 - I haven't driven it since January 9th. Yesterday, I went to my garage, expecting the Battery to be discharged, as it has happened before. However, I didn't anticipate being unable to unlock the doors at all. It seems like the 12V Battery is completely dead. I tried unlocking it with the key, but that didn't work either. You can see a  short video of me attempting to unlock the doors here (rest assured, I spent at least half an hour there; this is just a brief demo showing my efforts). I also tried the backup key, applied some WD40, and said a prayer. I'm positive that I was able to unlock the doors before with the key - it just clicked. However, this time, it doesn't work.

I found a post on a different Toyota forum (not sure if I can post it here, but you should be able to find it: "Toyota hybrid Battery dead key not working" on Toyota Nation's website). Based on that, I figured out that some hybrids can't be opened mechanically when the 12V battery is completely dead?? Some people even tested this with the 12V battery connected/disconnected. I still can't believe Toyota would do that, but after a sleepless night, I'm slowly losing hope.

I'm based in Slovakia. I called my insurance company, and they advised towing the car to the nearest Toyota dealer. However, this is impossible as the car is parked in the garage, and I can't put it into neutral (there are other garages opposite mine, and steering is needed to get out). I'm thinking a locksmith is my only option, but so far, I haven't been able to find one who can open a fairly new car. I saw a video where someone opened the doors with balloons; so far, this seems like the best option? Am I going crazy, or you really can't open a Corolla Hybrid with a mechanical key when the battery is completely dead? Has anyone been through this? Any other tips on how to get into the car?

Thanks.

[Chas G]

@Fake_Empire sorry to hear of your problem. I hope you manage to sort it out. I assume the door lock isn't frozen??

If all else fails a set of wheel dollies would move the car to a place where it is accessible. 

 https://www.sgs-engineering.com/catalog/product/view/id/2927/s/ws4000-680kg-wheel-skates/?gad_source=1&gclid=Cj0KCQiAn-2tBhDVARIsAGmStVl4uhywcFvJx8HkGiks2JRZoeCVM4c9zep0cIA2ERFu-VWvAaZPb50aAuPiEALw_wcB

[Roy124]

On 1/23/2024 at 1:31 PM, TrackLink said:

Unfortunately I forgot to remove these connectors from the battery of my previous car before selling it to Toyota as part exchange for my new Corolla 🤪.

You could buy a new tail, have I.  However the dealer plans to swap out my dashcams.

 

[Roy124]

@Fake_Empire while a locksmith might be an obvious answer, there is another option.  Do you have breakdown insurance?  Many, such as AA in UK are adept at opening cars when owbers contrive to lock themselves out.

[AEG]

On 7/16/2022 at 9:27 PM, Geoffrey Bailey said:

Toyota guidance as follows:

Toyota hybrids generally contain two batteries: a 12-volt Battery (which powers systems such as the headlamps and audio) and a high-voltage hybrid system Battery (which supplies the power to start the combustion engine and drive the electric motors).

The simplest way to maintain charge in both of these batteries is to simply go through the normal start procedure: press the ‘Start’ button with your foot on the brake and ensure the ‘Ready’ light is illuminated on the dashboard.

We recommend you put the car in ‘Ready’ mode for about 60 minutes before switching it off again and repeat the process at least once a week.

With regards to the information above, I'm interested to know what is the charging rate from the hybrid system Battery to the auxiliary Battery whilst in ‘Ready’ mode.

(Toyota Corolla Hybrid 1.8 owner)

[APS]

On 1/23/2024 at 4:19 PM, Sergus said:

Has somebody tried Defa onboard charger, like 1205 or 1210 flex?

No I have not tried their chargers. Defa is mostly popular in its native Scandinavia and countries with colder climates. Hence not much experience in the UK. However, having used many of their products over the years I see no reason to believe their chargers would be anything but of very high quality. Good option for a more permanent installation that charges your Battery while pre-heating the engine too. 

[AEG]

On 7/16/2022 at 9:27 PM, Geoffrey Bailey said:

Toyota guidance as follows:

Toyota hybrids generally contain two batteries: a 12-volt battery (which powers systems such as the headlamps and audio) and a high-voltage hybrid system battery (which supplies the power to start the combustion engine and drive the electric motors).

The simplest way to maintain charge in both of these batteries is to simply go through the normal start procedure: press the ‘Start’ button with your foot on the brake and ensure the ‘Ready’ light is illuminated on the dashboard.

We recommend you put the car in ‘Ready’ mode for about 60 minutes before switching it off again and repeat the process at least once a week.

With regards to the information above, I'm interested to know what is the charging rate from the hybrid system battery to the auxiliary battery whilst in ‘Ready’ mode.

(Toyota Corolla Hybrid 1.8 owner)

I checked the charging rate on the 12v Battery which was approx 40% charged and it was 14A to start with. This slowly dropped. I used a current clamp metre to take the measurement.

My 2.0  Hybrid, would drop from 90% SoC charge down to  30% SoC in 6 days if left unused. The car would not start. The voltage reading across the Battery was 10 Volts  unloaded. 

 

[Pannett]

For the second time. our Corolla wouldn't start today (Thursday). Fortunately the car was at a garage with a booster pack, so we were able to start the car and drive it for a while to charge the Battery. Last Saturday we did about 60 miles, then on Monday we did 4 miles and Tuesday we did 18 miles. The car  stood for three days and then would not start.  This is worrying: for example if we go on holiday and leave the car at the airport car park for a period of time, it's highly likely that the car won't start on our return. The car is awaiting a call from the dealer to do some overnight testing of the Battery, but does anyone know of a fix? If not, I am considering rejecting the car because it is not acceptable that this problem occurs and could be serious if we are on the Moors with our dog in the boot and no 'phone signal to call for help.

[sportse]

The dealership can run it though a Battery tester to check the health as well as the overnight test. 
 

depending on the Battery type, they can be damaged if they have gone flat and never recover fully so have to be replaced. 
 

a normal healthy Battery that’s been driven as yours should last at least 2-3 weeks when the car is locked and not used. 

[SDR]

16 hours ago, Pannett said:

For the second time. our Corolla wouldn't start today (Thursday). Fortunately the car was at a garage with a booster pack, so we were able to start the car and drive it for a while to charge the battery. Last Saturday we did about 60 miles, then on Monday we did 4 miles and Tuesday we did 18 miles. The car  stood for three days and then would not start.  This is worrying: for example if we go on holiday and leave the car at the airport car park for a period of time, it's highly likely that the car won't start on our return. The car is awaiting a call from the dealer to do some overnight testing of the battery, but does anyone know of a fix? If not, I am considering rejecting the car because it is not acceptable that this problem occurs and could be serious if we are on the Moors with our dog in the boot and no 'phone signal to call for help.

This seems to be a running theme, to a certain extent on Corollas, and perhaps more so on the Yaris.   Out of interest, is yours a 1.8 or 2.0?

I think that I have just kind of accepted that this is an unwelcome characteristic of the car.   I already had an Optimate smart charger, from biking days, so I've wired the lead to the Battery.   I give it a top-up charge if I'm not using the car for a few days.   My Optimate is really intended for bike batteries - charges at 0.8A max - but the Corolla Battery is only 45Ah and it works fine.

I also carry a Li-ion jump starter in the car.   They are small and light.   It doesn't need to be very powerful because the 12v Battery doesn't actually start the car (as in turn over the engine), it just initialises the systems.

[FROSTYBALLS]

12v Battery issues are relatively commonplace on hybrids, and affect other makes as well. 

[SDR]

15 minutes ago, FROSTYBALLS said:

12v battery issues are relatively commonplace on hybrids, and affect other makes as well. 

That may be so although, as a by-the-by, my brother has a Mitsubishi Outlander PHEV (2015) that has never had 12v Battery issues. 

I believe that some Hyundai/Kia hybrids have a button on the dash that gives the 12v Battery a boost from the traction Battery in case the 12v battery is too low to start the car?   I'm sure that I have seen same, probably in a Hyundai, although I don't remember the details.    That does seem like an acknowledgement of a problem but at least with a solution. 

All I would say, as a (long time) former electrical/electronic engineer, is that if this is a common problem then it is a symptom of poor design. 

I am not suggesting that other car manufacturers are any better, mind!

[sportse]

1 hour ago, SDR said:

 

I believe that some Hyundai/Kia hybrids have a button on the dash that gives the 12v battery a boost from the traction battery in case the 12v battery is too low to start the car?   I'm sure that I have seen same, probably in a Hyundai, although I don't remember the details.   

Yes, I was looking at Hyundai's a while ago - it seemed to be a virtual Battery without an actual real 12V one fitted.

The computer sets aside a portion of the main big Battery to use as a 12V one.

If it goes flat, you push the button and the computer just allocates a different part of the big Battery to use as a 12V one and the car starts up. Provided you have power in the big battery.

[sportse]

2 hours ago, FROSTYBALLS said:

12v battery issues are relatively commonplace on hybrids, and affect other makes as well. 

My Yaris had a tiny little Battery under the back seat, so hardly any power in it.

The newer models do seem to be better, my Corolla has a decent size Battery that you would be likely to find in a normal petrol car.

Maybe Toyota has learned from all the issues from having small batteries.

[TonyHSD]

That’s not the case in Hyundai kia cars, they do have physical small 12v batteries similar to Toyota hybrids and they do suffer similar faith in some models. The option to recharge from the traction Battery does work on evs as I tested it and no need to press a button, the car does it automatically when it’s necessary, however on Toyota hybrids the traction batteries are so small that this is not an option.  
The op has its Battery dead and even if it’s showing ok on the dealer tests he should request a new Battery replacement. It seems this Corolla doesn’t get enormously drive time to maintain good battery charge. If we do short trips and each time the car is on for less than a 30 mim this will kill the battery, plus the latest models has added connected services, all that equals premature battery failure 🪫