12v battery maintenance, issues, etc.

[Roy124]

38 minutes ago, TopGeek said:

Interesting. A few years ago, a woman damaged my car in a UK  supermarket car park and neither the police nor my insurance company were interested on the grounds that it was on private property.

Well I damaged another car in a very small Tesco car park, the police traced me using the store CCTV and I received a notice of intended prosecution.   It was out of time and the PC concerned was clearly sympathetic and told mecto tear it up.

[Derek.w]

You can lock the doors in ready mode just to keep yourself & goods not out of site safe 

door will open if you operate the door handle front doors anyway rear doors depending on child lock settings.

[TopGeek]

I don't know if an anecdote about anther brand of hybrid is acceptable here but I'll try it anyway.

This weekend, my daughter found her Kia Niro was dead. She had driven well overr 100kms the previous day so the Battery should have been fully charged. She called the breakdown service and the guy used his booster while telling the usual story about flat batteries being a common problem with hybrids. He never mentioned the fact that the Niro has a Battery Reset button. This is a safety feature that disconnects the Battery before the voltage drops too low. I imagine that protects  against a flat battery in situations like leaving the car with the lights on. The car is booked in for a check-up anyway.

[TonyHSD]

5 hours ago, CruxisCore said:

Can someone confirm/deny whether the remote control AC function will start ICE if necessary or will it only use the traction battery to the extent it can?

Cos if that function will star the ICE if battery level needs it, then it was probably that.

In these cars yes. Without car being set into ready mode no ac will be available. And when set in ready mode the ice will kick in to recharge the Battery. AC can quickly dry your hybrid Battery if it’s hot outside and need more power to cool down the cabin. This function works the best in electric cars as those has larger batteries. 

[TonyHSD]

24 minutes ago, TopGeek said:

I don't know if an anecdote about anther brand of hybrid is acceptable here but I'll try it anyway.

This weekend, my daughter found her Kia Niro was dead. She had driven well overr 100kms the previous day so the battery should have been fully charged. She called the breakdown service and the guy used his booster while telling the usual story about flat batteries being a common problem with hybrids. He never mentioned the fact that the Niro has a Battery Reset button. This is a safety feature that disconnects the battery before the voltage drops too low. I imagine that protects  against a flat battery in situations like leaving the car with the lights on. The car is booked in for a check-up anyway.

I have seen some electric cars can use their traction Battery to recharge their auxiliary 12v Battery. Kind a like onboard smart charger. Very cool. Nissan Leaf 2016 and Hyundai ioniq ev 2021 particularly. 

[Dala]

today two new information for me :

1/ at a voltage 12.2V ( SoC 60% ) a large reduction in parasitic drain

2/ at a voltage 12.1 V, the system charges the car Battery while driving 14.1 V approx. 40 minutes ( the headlights OFF ), then the system maintains the voltage at 12.8V

two rides today -  in the morning headlights OFF -  in the evening headlights ON

my measurement shows the following results:

driving during the day ( headlights OFF), the system charges the car Battery with a voltage higher than 14V, when the car Battery voltage is less than 12.13V before start driving (SoC 55%)

at a voltage 12.2V (SoC 60%) or more before driving during the day ( headlights OFF), the system only maintains the car battery at a voltage 12.8V

[TopGeek]

16 hours ago, TonyHSD said:

I have seen some electric cars can use their traction battery to recharge their auxiliary 12v battery. Kind a like onboard smart charger. Very cool. Nissan Leaf 2016 and Hyundai ioniq ev 2021 particularly. 

I presume the no-start situation on the hybrids is an indication that the traction Battery is also low on charge, otherwise it would maintain the 12v Battery.

[CPN]

29 minutes ago, TopGeek said:

I presume the no-start situation on the hybrids is an indication that the traction battery is also low on charge, otherwise it would maintain the 12v battery.

Not so. When the car is "off", the HV contacts are open and so the traction Battery is completely disconnected from the rest of the car and cannot therefore charge the 12v Battery.

[TonyHSD]

36 minutes ago, TopGeek said:

I presume the no-start situation on the hybrids is an indication that the traction battery is also low on charge, otherwise it would maintain the 12v battery.

No,

Toyota hybrids are very different from full electric cars and their traction batteries are tiny in comparison to bev’s.
This is the reasons why they can’t do this.
The hybrids batteries soc only matters in relation to starting the engine then the engine becomes generator for electricity that is directly used to propel the car and recharge the hybrid Battery. 
There are very rare occasions of non starter hybrids because of low traction batteries, due to been left unused for months or years, or driven after run out of fuel, or flash floods damage etc.

[TopGeek]

OK. Thanks for the info. In any case, there is room for improvement. No doubt the Battery Reset idea is patented but something similar will have to be developed to get around this very annoying common phenomenon.

[Dala]

another proof that long drives are not the solution to the problem

[TonyHSD]

Any chance these later cars with 12v Battery problems has actually inverter issues or software issues instead? 
Make sense longer you drive more charge to add to the Battery.
Even if been  top up quickly, then discharge a bit , then top up again, if this is how they work still should be fine.
On my last playing with the Battery on my Auris I noticed that 40 min in ready mode topped up the battery full from 12.3v when opened the door to 13.0v when switched off the car and measured. After 4-5 days of inactivity the voltage slowly drops to 12.2v but always unlocks and starts. Even on initial start up the voltage drops to 10.8v and still works.
 

[CruxisCore]

I think that once again very clearly shows that the magic number is around 12,3v. It more or less seems to ensure the Battery is above 12,3v and that it only charges it every now and then to keep it above that level. Why? Almost certainly cos literally every single milliamphour it pushes into the 12v is away from what you could've drive with electricity.

So again, they've looked for a sweet spot where the Battery (more or less) is charged enough to keep it up and not a smidge more to ensure best hybrid driving efficiency.

I'm like 99,9% sure this is deliberate and it's not a bug or a fault although one could argue that it should charge more. Also 99,9% certain this could be changed by an over the air update if they wanted to. Again, I feel they should allow some kinda "12v mode", where it charges the 12v more with the tradeoff of EV drive %

[Dala]

43 minutes ago, CruxisCore said:

I think that once again very clearly shows that the magic number is around 12,3v....

the problem is in the second magic number: 12.4V - sulfation car Battery

12.4V is voltage when a Battery is stored,  these values are different when the voltage is drawn (I found values 11.9V-12.3V for the car)

 

[CruxisCore]

37 minutes ago, Dala said:

the problem is in the second magic number: 12.4V - sulfation car battery

12.4V is voltage when a battery is stored,  these values are different when the voltage is drawn (I found values 11.9V-12.3V for the car)

 

I think it's not a great concern when the Battery is still constantly being charged with 13-14V and it's state of charge lives all the time. Stored Battery is quite different to one that is in active use. I havnt heard of Toyota batteries suffering from at least external sulfation, but who knows what goes on inside. 

It can definitely be a factor for the longevity of the Battery. Like here people are saying they have old ICEs with 10+ year old batteries, so maybe these new Hybrid cars will only have their 12Vs last for like.. 5. 

But it kinda doesnt matter if it's 5 years or 10 years. Battery is a consumable that is not expected to last 10 years. Of course problem arises if the sulfation was the cause for batteries dying within a year or something.

[MaDProFF]

I think the 12 volt batteries in todays cars are abused much more, same as cars that introduced the stop start engine when you stop, batteries in those cars started to have a lower life span, non charging hybrids again the batteries are abused more, on a side note, Tesla's more common call out fault is guess what? The 12 volt Battery issues, although Tesla are going to get rid of the 12 volt Battery altogether and go to 48 volt, much less copper in use, and more robust batteries

[Roy124]

2 hours ago, MaDProFF said:

think the 12 volt batteries in todays cars are abused much more,

Used not abused. 

For hybrid they do not have to power a starter motor.

My last car was specified for a stop start Battery though the car was not equipped to stop start.  I think it was almost 3 times the size of the Battery for a hybrid.

I think they do not have the capacity, charge, and load properly configured at the moment. 

[Tommy X]

I have removed the cover from the rear seat to find out the make of Battery fitted to my car first registered May 2023, just a plain white plastic on all four sides, maybe it's on the top but didn't yank the seat up so no wiser, under a flap on the red cover I found a connector similar to the jump/ charging point in the fusebox under the bonnet, maybe it's another jump/charging point, any ideas ?   

[Poohs]

Tommy X,

Yep, it's another "easy access" connection point to the 12 volt Battery positive terminal - well, that's what I've used it for when experimenting with connecting a Battery saver to my wife's Yaris.  Achieved exactly the same result as connecting the Battery saver to the jump-start connector in the under bonnet fuse box.

I suspect it isnt mentioned in the user manual as it's intended for technical use by mechanics or engineers.

Since my last post, the vehicle has been back to Toyota for a 24-48 hour parasitic current draw test - no fault found, battery "okay" was the result.  They did do a software update for something listed on their database that had been known to drain the 12 volt battery, but this made no difference.

When taken delivery of, the vehicle would need jump starting if left unused for 8 to 10 weeks, but now some 30 months later it now only takes 5 to 6 weeks, so I assume the 12 volt battery is loosing capacity - as it's a faff, I dont always connect the battery saver.  The car is kept garaged so short of wrapping the car in a duvet, it couldnt have a less hostile environment for the 12 volt battery to hang on to its charge.

I'm currently in the process of getting the car booked in for an extended parasitic current draw test (they said maybe 72 to 96 hours), but if this is also "no fault found", I'll give up.  It shouldnt be this way, but I shall probably replace the 12 volt battery with a higher capacity rating one at my own expense and just live with this "feature" of Toyota hybrid's design.

[Derek.w]

4 hours ago, Tommy X said:

I have removed the cover from the rear seat to find out the make of battery fitted to my car first registered May 2023, just a plain white plastic on all four sides, maybe it's on the top but didn't yank the seat up so no wiser, under a flap on the red cover I found a connector similar to the jump/ charging point in the fusebox under the bonnet, maybe it's another jump/charging point, any ideas ?   

It defiantly a jump start / Battery charging post. It was nice of Toyota to have the Battery info on the top of the Battery but its at the back in line with the positive post.

So if you carnt see it from bove because of a seat protector thats fixed under the seat cushion you have to slide the battery out to read it and that will mean disconnecting the battery posts.

Negitive post first.

[Derek.w]

8 hours ago, MaDProFF said:

I think the 12 volt batteries in todays cars are abused much more, same as cars that introduced the stop start engine when you stop, batteries in those cars started to have a lower life span, non charging hybrids again the batteries are abused more, on a side note, Tesla's more common call out fault is guess what? The 12 volt battery issues, although Tesla are going to get rid of the 12 volt battery altogether and go to 48 volt, much less copper in use, and more robust batteries

Tesla are using 16 volt model 3 batterys but they are extreamly small Li-ion type and are extreamely expensive.

[Tommy X]

2 hours ago, Derek.w said:

It defiantly a jump start / battery charging post. It was nice of Toyota to have the battery info on the top of the battery but its at the back in line with the positive post.

So if you carnt see it from bove because of a seat protector thats fixed under the seat cushion you have to slide the battery out to read it and that will mean disconnecting the battery posts.

Negitive post first.

Thanks Poohs and Derek, thought that's what it was, I was just curious to find the make of Battery on my car as some posters on this topic were interested in types of Battery fitted, I'm in the "If it ain't broke don't try and fix it" camp so won't be delving into removing the battery 😉 Cheers    

[Derek.w]

The Yaris and the Yaris cross may use diffrent types of Battery technology.

[MaDProFF]

3 hours ago, Derek.w said:

Tesla are using 16 volt model 3 batterys but they are extreamly small Li-ion type and are extreamely expensive.

I am talking about the 12 volt on the tesla, the 12 volt Battery to be replaced with a 48 volt system in the future

[anchorman]

I’ve dealt with two of these frequently discharged Battery cars and appear to have cured them with Yuasa higher capacity batteries.  They cost £83 each and to be honest, for that and about 20 minutes time, I couldn’t be bothered to trail back and forth to the dealer while they go through these extended tests.  I’m sure the batteries meet the spec new but they get to a precipice point where they don’t respond to charging.  One of them in particular was getting a no start condition after fairly lengthy runs that didn’t make any sense.  The Battery had plenty of time to absorb a charge.