12v battery maintenance, issues, etc.

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Regarding the lights, they are intended for connection to the battery to tell you the state of charge and whether you need to use the charger. 

I will try in the future. I have it as a reduction between a fixed connection from the solar panel (it will be used the most) and a 220V charger.

I had a long run in the car last weekend, over 2 hours driving.  Out of interest I measured the Battery voltage half hour after getting home, it was 12.42v seems a little low for a fully charged Battery I was expecting it to be higher.

What were you expecting?

3 hours ago, Trewithy said:

I had a long run in the car last weekend, over 2 hours driving.  Out of interest I measured the battery voltage half hour after getting home, it was 12.42v seems a little low for a fully charged battery I was expecting it to be higher.

I think it’s absolutely fine. You can try to measure when your brake pump depressurises and see what the voltage will be, if it drops below 11v the Battery is weak. To do that start the car open bonnet or boot and gain access to your 12v Battery, get ready to measure , turn off ignition, leave drivers door slightly open and go quickly to the Battery, hook up your terminals and watch the voltage how much will fluctuate when you hear the pump noise from the front probably a minute later after you turned off ignition. 👍

As it happens I tested my Battery voltage yesterday a few minutes after a 2 hour journey.  It was also exactly 12.42v

I am amazed that people are just accepting this problem with these Toyota batteries.My brother has 2021 yaris hybrid and he had no problems with it when bought from new.Driving the same way as before and now Battery will only last 2 days parked up.This should not be happening.In the 1970s I had Skoda coupe could leave it in snow and cold and never refused to start.Car company's know they are having a lot of sub standard batteries, I had to buy new Battery myself after less than 2 years this was not a hybrid car was Seat Ateca.Rise up and look for car makers to supply new Battery.

It is disappointing to read this is still such an issue on hybrid cars which have a secondary Battery. I have fitted a larger Battery and solar panel to my old ICE RAV4. I was hoping I wouldn’t have this annoyance on a new modern car.

Why do they insist on fitting a tiny P9 and have systems which have a parasitic drain?

On 1/21/2022 at 6:55 PM, Joby1 said:

Hello

I’ve have a 2020 new model yaris hybrid. In the last 10 days I’ve had to get roadside assistance twice as the 12v Battery was dead. First time the car had been stationary for 3 days, the second time 2 days. Dealership today checked if there was a electrical fault (no) but said it needed a full charge up, which they did. Issue is - apparently flat 12v Battery is a hybrid issue (due to of engine running from hybrid Battery mainly it doesn’t fully charge the 12v.) Apparently there have been cases of people going on holiday for 2 weeks, coming back to a dead battery. I’m concerned as over the next few months due to work I will be leaving my car a few times for a week or two at the airport.

Seems a serious design fault of Toyota when they have a strong reputation for reliability!  
Has anyone else experienced this? Does anyone have a solution? Am thinking I may well be better to sell the car and start afresh. 
Thank you for any advice. 

I am having the same problem, and simply fail to understand the complexity! Why two batteries with no ability for each to back up the other? Why is the control system (which seems to be what goes flat) not on THE most reliable Battery?

Toyota- lift your game! I have owned my Yaris Cross Hybrid for about a year, and this issue has caused me to call roadside assist now 4 times! they mean well, but each come up with different solutions! The local dealer is hopeless "not our problem"

I am going to tell you what has been said by others. Making claims like "Toyota-Lift Your Game" will only be seen by forum members. TOC is not affiliated in any way to Toyota the car manufacturer. If you want to get your message across to Toyota you need to contact them via your importer .

Obviously, you are not the only one to suffer this Battery issue over the last 12 months, as you know. But it would be better if everyone was coordinated and at a set time on a set day you all contact Toyota direct, flood them out with the same message and they may "get the message" that lots of their customers are not happy.

It does seem to be a combination of the Smart entry system and also people not using the cars enough. I have noticed with Toyota vehicles, esp. the more efficient ones like the old diesels and the hybrids, that they expect to be used regularly. When they aren't, that's when they tend to develop issues, and not just the Battery draining!

It is surprising to me that it is still an issue tho', given how long this 12v drain has been a problem in their older cars.

What market are you in (AU ?) as the Yaris cross wasn't released till late 2020, why are there 2 batteries, safety even tesla use 2 the 12v and HV - replace the 12v Battery or put a Battery maintainer on it 2019 to 22 cars had lots of Battery issues due to car sitting especially when new and coming into the country,

The battery is an AGM type* and needs to be charged low and slow the DC to DC inventor is intelligent and doesn't charge all the time, it can take up 200 miles to get a full charge or 48 hours on a charger off the car - *some new cars use a lead acid

The battery is only covered for a year a dealer with fast charge a battery then test it, it then tests good do this a few times, and it spanks the battery

TLDR: suck it up and buy a new battery - oem is Yuasa or ask if they will do it as goodwill

1 hour ago, QldStew said:

I am having the same problem, and simply fail to understand the complexity! Why two batteries with no ability for each to back up the other? Why is the control system (which seems to be what goes flat) not on THE most reliable battery?

Toyota- lift your game! I have owned my Yaris Cross Hybrid for about a year, and this issue has caused me to call roadside assist now 4 times! they mean well, but each come up with different solutions! The local dealer is hopeless "not our problem"

The problem is, all the computers run on 12v, as do the door locks, lights etc.

The Nissan Leaf for example, will start charging the 12v Battery from the bigger Battery. But, there's one big difference.

The big Battery in a Leaf is a minimum of 24kWh. The 12v battery in a Yaris is 0.4kWh, the big battery is 0.7-0.8kWh.

You simply don't have enough in the big battery to keep topping up the smaller one, and a discharged HV battery can be a nightmare.

The HV is protected you need the 12v Battery to engage the contactors

don't mix up BEV and Hybrid as they are vastly different

What's different in this case though? Both rely on 12v contactors to engage the Battery, both charge the 12v Battery through a DC-DC converter. The difference is that some EVs will engage the contactors to charge the 12v Battery when the vehicle appears 'off' and whilst it isn't plugged in.

The problem for the Hybrids is that the 12v battery isn't that much smaller than the HV one, so charging it would require a not inconsequential amount of power from it. You'd not get many chances before flattening your HV battery.

Hyundai in their some of their HEVs and PHEVs use a Lithium 12v battery with a generous low voltage cut out. There's a button in the cabin to override that cut-out and still start the car.

Today I tilted the solar panel to a slope of about 35st
According to measurements, the solar panel works fine and gives 0.8V more than when it is laid
Outdoor temperature at night -5C to -7C
Without recharging by the solar panel, the car Battery has 12.2V - 12.3V in the morning 

10:00 - 12,5V

11:00 - 12,9V

11:15  - 13,2V

11:45 - 13,5V

12:15 - 13,7V

13:30 - 13,5V

14:00 - 12,9V

14:30 - 12,7V

16:00 - 12,6V

On 3/14/2022 at 11:20 AM, flash22 said:

The HV is protected you need the 12v battery to engage the contactors

don't mix up BEV and Hybrid as they are vastly different

It says hybrid on the Badge, manual, and key. What is BEV? 

It's an abbreviation of  Battery Electric Vehicle (i.e what most people call an EV nowadays).

(As opposed to:

HEV - Hybrid Electric Vehicle - e.g. Prius, Corolla

PHEV - Plugin Hybrid Electric Vehicle - e.g. RAV4 Prime, Outlander

FCEV - Fuel Cell Electric Vehicle - e.g. Mirai)

Which app are using to monitor Battery voltage ?

it is a car alarm - it also has car Battery voltage monitoring 

https://pandorainfo.com/shop/pandora-smart-pro-v3/

unfortunately the remote start does not go to Yaris

I have a Toyota Yaris Hybrid 1497 Hybrid  from model year 2013.  

I need to replace the 12V Battery because it has gone flat.  

Nobody will do this for me and nobody can explain why or direct me to a service which can.  

I cannot take the car to a dealer without paying for a flatbed truck, which seems excessive for a simple Battery change.  

Toyota dealer doesn't want to advise as usual - they're only interested in selling new cars.  

I have this issue on an older Yaris Hybrid.  

It is absolutely infuriating.  It makes the car completely unreliable as you never know whether it will start after not being used for a couple of days.  

Toyota dealers don't want to know.

Are you not a member of a breakdown service (eg. the AA or similar)??

17 minutes ago, BanburyMan said:

I have a Toyota Yaris Hybrid 1497 Hybrid  from model year 2013.  

I need to replace the 12V battery because it has gone flat.  

Nobody will do this for me and nobody can explain why or direct me to a service which can.  

I cannot take the car to a dealer without paying for a flatbed truck, which seems excessive for a simple battery change.  

Toyota dealer doesn't want to advise as usual - they're only interested in selling new cars.  

Sorry to hear you have a bad experience with typically a reliable car. 12v Battery in Toyota hybrids and most other cars from post 2010 my can go flat in the car has not been used regularly. Been a hybrid the car has a small 12v Battery that requires a regular drive for over 20-30 min each time or regular maintenance with external charger, your local dealer should have explained all that. Since the car has a completely dead Battery best practice is to buy a new exact type replacement battery, fit and measure if the inverter charges the battery correctly when the car is in ready mode (ignition ON and ready to drive). After that it is a good idea to buy a smart charger like ctek 5 or similar and once a month to connect and recharge your new battery to prolong its life. If you use the car often you don’t need to worry about it. You can search in Google for local mobile mechanic and book an appointment for battery replacement at your address. Batteries are available online or from Toyota dealers. Suggestion to keep the car in ready mode as long as you can when in use also helps to keep your battery in healthy condition. 
Regards 

AA, RAC and Halfords and all similar services claim to be out of stock on batteries for Toyota Yaris Hybrid.  There is clearly an issue here and they don't want to touch it.  

1 hour ago, BanburyMan said:

I have a Toyota Yaris Hybrid 1497 Hybrid  from model year 2013.  

I need to replace the 12V battery because it has gone flat.  

Nobody will do this for me and nobody can explain why or direct me to a service which can.  

I cannot take the car to a dealer without paying for a flatbed truck, which seems excessive for a simple battery change.  

Toyota dealer doesn't want to advise as usual - they're only interested in selling new cars.  

It is a straight forward job to change batterie, Adam. Try You Tube for a video  "12v Battery replacement Toyota Yaris hybrid."         

Wear a pair of gloves and eye shield for safety.

Disconnect the negative connection first, that is the black connection. Put it somewhere away from the red cable/terminal.   

Disconnect the positive terminal, the red terminal. Put that away from the black cable/terminal.

The new Battery should be the same as the one removed, make sure the connectors are the right ones and positive connection is the same position as the old one. If the old Battery as a tube venting maybe through the floor then the new one must have Omit that if your battery is under the bonnet). Like for Like.

Putting the new battery in is reverse of the above ie red connection first, then black connection.

You can put some silicone grease, or better still dielectric silicone grease, on the 2 battery terminals.

Make sure the terminals are fastened up well.

The new battery may or may not be well charge, so do as Tony said above....... either take it for a good run at least 40 minutes OR in a safe place switch the car on so READY shows on the dash (tis is the position just before you put in D or R and drive off. Do this for 40 minutes.

Do the above charging regularly, once or twice a week in winter, probably only once in summer IF you do not use the car regularly or for only short runs.