12v battery maintenance, issues, etc.

[Corolly Poly]

19 minutes ago, RabButler said:

How does the car know you have disabled the key?

From what I understand I think it stops looking if it doesn't see a key for a while. This should also happen when the key is too far away such as in the house (or in a Faraday pouch), although with lots of houses if you keep the keys in the hallway and the car on the drive it will still be able to communicate. I think this is a security risk as well as a Battery risk.

[forkingabout]

Remember newer Toyota products have motion sensing keyless fobs which stop transmitting the signal after a few minutes once they stop sensing movement. 

No real need to switch the keyless system off or place these in a Faraday pouch.

[Cyker]

1 hour ago, RabButler said:

How does the car know you have disabled the key?

If it's a keyless entry fob, you hold down LOCK and press UNLOCK twice and it turns the fob transmitter off until you press one of the buttons again - Saves the Battery life of the fob and makes it impossible to use relay attacks on.

It won't make much difference to the car's Battery (Unless it's draining because the fob and car are too close and they keep pinging each other) - For that you need to turn of the smart entry system completely which shuts down all the power hungry keyless entry transmitters. (But not the remote unlock receivers, which use much less power)

IF you use the car regularly there's no point, but if it's going to be left for a long time, e.g. holiday, that might reduce the power draw on the 12v Battery just enough that it won't be dead when you get back.

[SDR]

1 hour ago, RabButler said:

How does the car know you have disabled the key?

I am not 100% sure that it does (which is why I said "believe") but based on this from the manual:

• In the following situations, the smart entry & start system may take some time to unlock the doors.

  • The electronic key has been left within approximately 3.5 m (11 ft.) of the outside of the vehicle for 2 minutes or longer.

  • The smart entry & start system has not been used for 5 days or longer.

My car lives under a car port right outside my back door and the key is within 3.5m of the car.  I figured that car and fob are probably close enough to be communicating so I would prevent that by switching off the fob.   I am hoping that is sufficient without turning off the smart entry system completely.

I would do it anyway because of the relay theft issue.   For the last few years I had been keeping my car keys in a Faraday pouch - until I read this:   https://www.honestjohn.co.uk/askhj/answer/187360/do-faraday-pouches-wear-out-

Sure enough, I tested mine, it was useless.   With the keys in the pouch in the kitchen I could easily open the car.

Ironically, just about everyone has a really good Faraday cage in their kitchen.   A microwave;   and it really does work  (it has to or microwave energy would escape the thing).   Which is fine unless you turn it on with the keys inside...

 

[SDR]

2 hours ago, forkingabout said:

Remember newer Toyota products have motion sensing keyless fobs which stop transmitting the signal after a few minutes once they stop sensing movement. 

No real need to switch the keyless system off or place these in a faraday pouch.

It seems so but all I can find in the manual is this (I was actually looking for something else!):

The electronic key function is suspended when

The electronic key function may be suspended when the electronic key is kept unmoved in a same location for a certain period, such as it is left on a same place. This is to reduce Battery consumption. The function will be restored automatically when the electronic key is moved, such as it is picked up.

Problem is that it says "may be" and "certain period".   As with quite a lot of the manual, it's open to interpretation.   Without certainty that this applies to my car and, if it does, what the "certain period" actually is, I am not minded to rely on it.

[Red_Corolla]

Just to clarify, it's only the keyfobs that supposedly go to sleep when sitting still. The car system continues to make transmissions to try and detect a fob that's both awake and in close proximity - this does turn off eventually, but it takes a couple of weeks, unless it's been disabled altogether via the menu system. I did a crude study of the Battery draw a couple of years ago and you can quite clearly see the current spikes, just over a second apart, that disappear with keyless entry turned off. The net effect on energy consumption is significant, but not huge. Link below for anyone interested.

 

https://www.toyotaownersclub.com/forums/topic/203030-constant-battery-drain-problem/?do=findComment&comment=1602456

 

[TonyHSD]

The proximity sensors and the keyless entry are the smallest thing to worry about 12v Battery draining. Also this is one of the best extras these cars has and why would you like to disable it.
You will be better off to disable connected services, turn off all automatic functions like auto fold side mirrors, auto parking brake, home lights functionality if you have any of these. 

All these extras  can be done manually when necessary and while the car is still in ready mode to preserve 12v Battery. All electronic actuators are high energy consumers and the one low energy consumer but constantly draining the Battery are the connected services and possibly the poor network connection all around the country. Since introduction of 5G standard in 2020, and later removing 3G masts doing calls or using mobile internet has worsened a lot. Poor signal drains phone batteries faster therefore no surprises if it actually makes things worse for all these cars with modern tech inside. 

[Red_Corolla]

@TonyHSD I think it's important to consider the difference between power and energy, remebering that it's the latter that we need to limit in order to preserve the Battery charge.

Sure, folding the mirrors draws a lot of power, but it's over in 3 seconds. It's not really a high energy consumer unless repeated a few times every day (not forgetting the other activity generated by unlocking the car like priming the brake servo etc.).  So, it all depends on use case: if you're using the car a few times every day then the mirrors are going to be the higher consumer, whereas someone like me, who will often fold them up once and leave the car standing for several days, will most certainly need to worry more about the background activity........e.g. keyless entry.😄

[Roy124]

Stuart, good point about high energy consumers which bears out what I have observed.  Frequent restart cycles,  even if Ready mode gives you an hour a week, reduce Battery energy 

[W1P30UT]

So my new Corolla is with the garage for the second time to investigate the low 12v Battery warning. The car is driven regularly, with some long journeys, and still I get this warning. As a courtesy car I got one of the managers approximately six month old Corolla. Guess what? 12v Low Battery warning on that too!

[W1P30UT]

Here's the latest update from Toyota.

"We cannot fault the Battery itself in terms of drains or charging concerns, he has guided me in explaining that if you are sat with the radio on with ignition off then naturally there will be a draw on the vehicle as a whole and the 12v Battery would be subject to this, granted if its small increments at a time then in theory it shouldn’t be depleted allot however its important to  explain that small journeys or shorter increments over time with maybe sitting stationary the vehicle 12v Battery would be lower than when constantly used and thus wouldn’t ever return from full charge state as hybrids communicate differently compared to none hybrid cars and this impacts how the 12v battery responds vs switching to electric mode. If the vehicle feels it has enough 12v battery charge to not require more charge and stays in electric mode stationary for regular periods and the isn’t used for any substantial journeys, then this can create low battery queries on the dash based on regular like events. However, we have noticed that those who do regular journeys and moderate mileage over 12 months and by moderate in my experience over 6/7k a year we don’t have any 12v battery concerns but again everyone using their car is different. I think in this instance if you have done some shorter journeys and then been local this may well be because of a low battery warning."

In short, don't do local short journeys. I can't say I am happy with owning a car that support regular short journeys. What do people think?

[forkingabout]

Do you still leave the vehicle in accessory mode to listen to the radio? 

[Neptuneblue]

35 minutes ago, W1P30UT said:

Here's the latest update from Toyota.

"We cannot fault the battery itself in terms of drains or charging concerns, he has guided me in explaining that if you are sat with the radio on with ignition off then naturally there will be a draw on the vehicle as a whole and the 12v battery would be subject to this, granted if its small increments at a time then in theory it shouldn’t be depleted allot however its important to  explain that small journeys or shorter increments over time with maybe sitting stationary the vehicle 12v battery would be lower than when constantly used and thus wouldn’t ever return from full charge state as hybrids communicate differently compared to none hybrid cars and this impacts how the 12v battery responds vs switching to electric mode. If the vehicle feels it has enough 12v battery charge to not require more charge and stays in electric mode stationary for regular periods and the isn’t used for any substantial journeys, then this can create low battery queries on the dash based on regular like events. However, we have noticed that those who do regular journeys and moderate mileage over 12 months and by moderate in my experience over 6/7k a year we don’t have any 12v battery concerns but again everyone using their car is different. I think in this instance if you have done some shorter journeys and then been local this may well be because of a low battery warning."

In short, don't do local short journeys. I can't say I am happy with owning a car that support regular short journeys. What do people think?

If you’re unhappy with the car, sell it and buy a non hybrid. I’ve just done the same with my previous 5 month old car (Sportage hybrid) as it was too big for my lifestyle (and it had a number of annoyances) and bought the Corolla as it’s perfect for me. Life is too short to be stressing about a car. Move on. 

[SDR]

4 hours ago, W1P30UT said:

Here's the latest update from Toyota.

"We cannot fault the battery itself in terms of drains or charging concerns, he has guided me in explaining that if you are sat with the radio on with ignition off then naturally there will be a draw on the vehicle as a whole and the 12v battery would be subject to this, granted if its small increments at a time then in theory it shouldn’t be depleted allot however its important to  explain that small journeys or shorter increments over time with maybe sitting stationary the vehicle 12v battery would be lower than when constantly used and thus wouldn’t ever return from full charge state as hybrids communicate differently compared to none hybrid cars and this impacts how the 12v battery responds vs switching to electric mode. If the vehicle feels it has enough 12v battery charge to not require more charge and stays in electric mode stationary for regular periods and the isn’t used for any substantial journeys, then this can create low battery queries on the dash based on regular like events. However, we have noticed that those who do regular journeys and moderate mileage over 12 months and by moderate in my experience over 6/7k a year we don’t have any 12v battery concerns but again everyone using their car is different. I think in this instance if you have done some shorter journeys and then been local this may well be because of a low battery warning."

In short, don't do local short journeys. I can't say I am happy with owning a car that support regular short journeys. What do people think?

First thought is wondering who at Toyota (?) - or what (AI?) - wrote this garbage.   A candidate for a Crystal Mark from the Plain English Campaign it isn’t.    Auto-translated I suppose. 

Second thought is that if this the reality of owning a hybrid (Toyota and probably others too) then so be it;   the problem could be considered as not being with the cars but with dealer sales people who don't make this clear to potential buyers.   Diesel cars fitted with DPFs (so since 2009ish) aren't suited to regular short journeys either;   but do car sales people still sell them without asking potential customers about their intended use (rhetorical)?

[DV21VSV]

This problem is becoming common with new hybrids. I had similar with 2021 chr. I got a voltmeter and was horrified at the voltage capacitance.  Check the voltage at end of day and again next morning. I was getting up to 0.5v drop and after 2 days car failed to start. AA told me the problem is getting worse. Now I have a trickle charger as recommended by the toyota dealer service manager. The toyota 12v batteries can't even support a radio with engine switched off for over 4 minutes. The engine restarts because of the voltage drop. It can't support a next base 2k Dashcam in service with engine running cos that needs 13V. As I see it they have microdesigned the 12v Battery to only be able to supply engines run daily and to support the heavy demands of the cars engine and security monitoring systems. My next step is to buy Battery monitor with bluetooth feed to mobile that records voltage 24/7. They only cost £20. 

[W1P30UT]

Quote

13 hours ago, Neptuneblue said:

If you’re unhappy with the car, sell it and buy a non hybrid. I’ve just done the same with my previous 5 month old car (Sportage hybrid) as it was too big for my lifestyle (and it had a number of annoyances) and bought the Corolla as it’s perfect for me. Life is too short to be stressing about a car. Move on. 

 

Thanks, I am happy with the car. I am not satisfied with the 12v low Battery issue. My car is just over 1 month old. Why should I take a financial hit of depreciation for Toyota not designing a car to work with most normal use cases, or warn prospective buyers of the limitiation.

[W1P30UT]

Quote

9 hours ago, SDR said:

First thought is wondering who at Toyota (?) - or what (AI?) - wrote this garbage.   A candidate for a Crystal Mark from the Plain English Campaign it isn’t.    Auto-translated I suppose. 

Second thought is that if this the reality of owning a hybrid (Toyota and probably others too) then so be it;   the problem could be considered as not being with the cars but with dealer sales people who don't make this clear to potential buyers.   Diesel cars fitted with DPFs (so since 2009ish) aren't suited to regular short journeys either;   but do car sales people still sell them without asking potential customers about their intended use (rhetorical)?

 

Agreed it's a garbage statement. They should make this limitation clear to prospective buyers.

[W1P30UT]

7 hours ago, DV21VSV said:

This problem is becoming common with new hybrids. I had similar with 2021 chr. I got a voltmeter and was horrified at the voltage capacitance.  Check the voltage at end of day and again next morning. I was getting up to 0.5v drop and after 2 days car failed to start. AA told me the problem is getting worse. Now I have a trickle charger as recommended by the toyota dealer service manager. The toyota 12v batteries can't even support a radio with engine switched off for over 4 minutes. The engine restarts because of the voltage drop. It can't support a next base 2k dashcam in service with engine running cos that needs 13V. As I see it they have microdesigned the 12v battery to only be able to supply engines run daily and to support the heavy demands of the cars engine and security monitoring systems. My next step is to buy battery monitor with Bluetooth feed to mobile that records voltage 24/7. They only cost £20. 

I had thought of putting a 12v bluetooth monitoring on the Battery. But if the Battery has such a low volage capacitance I am concerned it will exasperate the problem.

[W1P30UT]

Quote

14 hours ago, forkingabout said:

Do you still leave the vehicle in accessory mode to listen to the radio? 

No.

 

[Roy124]

15 hours ago, W1P30UT said:

ts important to  explain that small journeys or shorter increments over time with maybe sitting stationary the vehicle 12v battery would be lower than when constantly used and thus wouldn’t ever return from full charge state

.... if the vehicle feels it has enough 12v battery charge to not require more charge and stays in electric mode stationary for regular periods and the isn’t used for any substantial journeys, then this can create low battery queries

........

we have noticed that those who do regular journeys and moderate mileage over 12 months and by moderate in my experience over 6/7k a year we don’t have any 12v battery concerns

......

If you have done some shorter journeys ..... this may well be because of a low battery warning."

And this is exactly what I have concluded from observing my Battery monitor data. Two hours driving per week with 2 journeys day of 12 minutes is not sufficient. 

We have been stressing that the essential criteria for Battery management was time not mileage but that should be quality time, ie the 'one hour per week in Ready mode'.  Ideally that should be for one hour and not an accumulated hour.  3x20 minutes or 2x30 minutes will probably be acceptable. 

"Just pop in to the shop Dear, I have to stay in the car for an hour."

Job done,  both happy.😀

[TonyHSD]

Funny but true. 
This is exactly the concept of all vehicles, petrol, diesels, hybrids or Battery electric and they all will suffer the same faith if you start stop driving them. 
This is the reason why on many delivery vehicles drivers keep engine running or on even if they arrive at their destination, to preserve Battery charge, stop and start frequently kills your Battery. 
For example, after new battery replacement it is best to use the car for longer time between on and off, 30 min or more each time.
If this is not possible , then solar charger, smart charger or ready mode once a week are necessary to extend the life of the new battery, otherwise it will slowly but surely degrade quickly and let you down. And if anyone argue, but all my previous cars had no issues at all , I will agree, but ask yourself a question., did all of them had connected services, huge screens and everything digital and electronic inside? 
It’s not just Toyota these days but all car brands suffer same problems. 

[fred88]

Anyone seen this? Not a great situation really.

https://www.honestjohn.co.uk/askhj/answer/189428/my-new-hybrid-keeps-showing-low-battery-warnings---should-i-reject-it-

[loz8]

Emergency services,[cops] are useing these models,how do they cope,a second Battery? I'll ask at upcomeing service.

[forkingabout]

5 minutes ago, loz8 said:

Emergency services,[cops] are useing these models,how do they cope,a second battery? I'll ask at upcomeing service.

The Police Corolla Touring Sports have a special Police equipment specification with many modifications.

https://media.toyota.co.uk/toyota-works-with-the-police-to-produce-new-corolla-patrol-car/

https://mag.toyota.co.uk/toyota-corolla-police-car-a-force-for-good/

[Roy124]

3 hours ago, fred88 said:

Anyone seen this? Not a great situation really.

https://www.honestjohn.co.uk/askhj/answer/189428/my-new-hybrid-keeps-showing-low-battery-warnings---should-i-reject-it-

The Question appears to be based on the classic ICE model with no knowledge of the new methods for a modern HEV.

No mention of the actual profile,  how were the long drives in relation to the short?  Was the radio used on ACC mode?  That used to be necessary in ICE to avoid overheating the coil or burning fuel unnecessarily.

The advice is as we have all said, Ready mode and a charger.

If you want the radio on when parked up, stay in Ready mode, switch AC off.