12v battery maintenance, issues, etc.

[TonyHSD]

Guys, you are thinking of a bit too much. 
Thete is no difference between driving or stationary. The alternator will provide constant voltage no matter of engine rpm. 
The dc to dc converter in Toyota hybrids too. The voltage fluctuation will depend on Battery soc and 12v system load. And my old car does behave exactly as your . Just coming in from troubleshooting a possible  12v Battery issue for a first time after 13 years & 249000 miles. 
Once the 12v Battery is dead is dead. 
Why yours in a new cars goes bang so quickly is another matter. Most likely connected services drainage  while car asleep, too many automated auxiliaries, additional cameras or gps devices, a lots of ECU’s, the DCM issues, a bad batches battery from suppliers, neglect by dealers while cars in transit and on PDI , lack of use by the owners. , or perhaps a combination of all above. 

[Roy124]

Core, that's why I said gather evidence then try and get a free,  or at least subsidised replacement. 

Of Phillipe bought it recently he has a better chance of a dealer replacement.

 

[Susan Shaw]

I have had the same problem on the Toyota Yaris Cross I bought in Nov 2022.  It has failed to start three times now after leaving it unused for a week.  Toyota have suggested a fit a solar panel to my windscreen at my own expense - so that I don;t need to use jump leads.  I am not happy with this response and believe it is a design fault.  Possibly the security system with this flashing dashboard light is draining the Battery - my best guess!  Talking to Toyota tomorrow again.  

[CruxisCore]

Have you had it properly charged since or is it just jump and go?

It'd probably be smart to actually hook it up to a mains charger for the night or whatever if it runs flat, still a chance to save it from a one-off flat Battery

[FROSTYBALLS]

Similar topics merged.

[Derek.w]

If using the car stationary just to charge the Battery I do not have the time to do that at least with a mains Battery charger I can lock the car up then go back after 4 or 5 hours and its fully charged.

[MCatPG]

This morning a van drew up beside me in a car park and the passenger introduced himself as working for a Toyota dealer. He asked how I was getting on with our car. I said OK but when is Toyota going to come up with a permanent fix for the 12V auxilary Battery problems? His response was to describe the problem from the dealers' perspective (short version: they are fed up with it). He mentioned getting a bigger Battery but I said the underlyng problems are the charging logic, including the lack of charge when in READY+P instead of READY+D, and the parasitic drains. He said the latter is the biggest problem because, wait for it, there are 52 ECUs in the car, all taking their own tiny little bit of current. 52 of the little blighters! I said that's madness and he agreed. But obviously that's something we are stuck with. My final remark was that all the hybrid manufacturers should be fitting charging points and telling customers that they need to provide an external charge to maintain their 12V auxilary batteries in good condition, and he agreed with that. However it's never going to happen and so perhaps this thread will live on for many years into the future. 

[Max_Headroom]

20 minutes ago, MCatPG said:

so perhaps this thread will live on for many years into the future.

It doesn't need to simply drive the car every few days or leave it in "Ready" when you are sat in the car at the supermarket etc waiting for your partner to do the shop, what better way to get out of doing that awful weekly trudge round the stores!

If i originally had no intention of buying a hybrid i would buy one for this reason alone 😉 

[Cyker]

It's fairly normal to have so many ECUs - They split off the functions instead of having one massive ECU that did anything to e.g. ease packaging, allow reuse across different platforms, improve repairability etc.

Most of them are unpowered when the car is off anyway.

The thing is, it should be fine under normal use unless you're one of the unlucky people who had a duff Battery to begin with (As they are just normal 12v starter batteries, once they drop below 50% charge they are irreparably damaged and, while they'll still work, will have lost significant capacity that they are unlikely to get back, even with a really good Battery conditioner).

I and many others haven't had a problem, but I use mine regularly for, not even necessarily long trips - Some of my trips are only a few miles, but as those few miles are crawling through traffic it takes a good chunk of time, and that time-on is what'll help keep the 12v batteries charged enough.

Still, it is disappointing that Toyota don't seem to have done anything to mitigate the problem - They've had these issues with 12v batteries in the past, again with the hybrid model being more prone to it. They're usually better than this at fixing known issues.

The main options for us to mitigate it are some combination of use the car more, fit a higher capacity Battery, use a trickle charger or carry a jump pack.

[RickyC]

23 hours ago, Dala said:

stationary parking 60 minutes

 

Except for two short peaks the DC-DC converter seems to just keep the voltage without charging the Battery. 

Obviously it could depend on the Battery state of charge.  Probably yours one is in good state.  Maybe in case the SOC is lower the 14V peak has a longer duration.    

[TonyHSD]

The number of ECU’s will definitely  affect  the Battery load but the biggest problem is when car is off and the stupid connected services, and in addition to that are all cameras or tracking device fitted as options in dealers. 
What Toyota should offer is an option that the owner can disable permanently these extras and not worry about if the car will start or not if left without use for a week. Also reading that agm batteries are better for hybrids, why some new models come without agm but with wet batteries? 
 

[Tommy X]

7 hours ago, MCatPG said:

 My final remark was that all the hybrid manufacturers should be fitting charging points and telling customers that they need to provide an external charge to maintain their 12V auxilary batteries in good condition, and he agreed with that. However it's never going to happen and so perhaps this thread will live on for many years into the future. 

Toyota do fit a charging point, it's located in the fusebox under the bonnet, my supplying dealer showed me how to connect a smart charger, no problems, I'll wait for the sarcastic comments 😉 

[Dala]

For WET batteries it is always written: not suitable for the START-STOP system.
I was looking for an AGM Battery for dimensions 175x175x190.
I only found one model.
Chinese Battery and only for the Russian market.

https://www.магазин-берёзка.рф/moscow/web-shop/shop?page=shop.product_details&flypage=garden_flypage.tpl&product_id=999&category_id=236

https://rdrive.pro/en/index.php

[Roy124]

I wonder:

A Toyota Hybrid just needs a fairly modest 12v supply to start the system as evidenced by the very small Li packs.

But we have a much larger Ca, Pb or AGM that is knackered if its charge drops below 50%.

A caravan with a 12v system does not have a problem with a deep cycle Battery.

Why can't hybrids use a deep cycle Battery.

[Cyker]

I have been wondering this for years!  

I thought they had started using them in their hybrids, but apparently no, still using normal starter batteries that are designed for short bursts of high energy output and don't like long low level drain. Heck, the Yaris Mk4 has even gone backwards, from the AGM Battery they started using, back to a bog standard flooded one!

At least they're relatively cheap to replace I suppose...

I do wonder if I could fit one of the deep-cycle AGM batteries we use in our UPS'...   (Could be tricky since they use completely different terminals and are the wrong shape and size  )

[Derek.w]

Cyker.

Yes I would like the answer to that one if you can just swap batterys or do the charger itself needs tobe told what type of Battery it is charging or will it just work it out for itself.

[Tommy X]

1 hour ago, Dala said:

For WET batteries it is always written: not suitable for the START-STOP system.
I was looking for an AGM battery for dimensions 175x175x190.
I only found one model.
Chinese battery and only for the Russian market.

https://www.магазин-берёзка.рф/moscow/web-shop/shop?page=shop.product_details&flypage=garden_flypage.tpl&product_id=999&category_id=236

https://rdrive.pro/en/index.php

The Yaris X doesn't use a conventional stop/start system,there is no starter motor and I wonder if it is wise to deviate from the type of Battery fitted as standard, just a thought.  

[TonyHSD]

I had a strange issue yesterday with my car. 
For some unknown to me reason the car has stopped recognising the key fobs, both of which had recently new batteries fitted. 
So what actually happened:  -  I had tried to unlock the passenger door but nothing happened, tried with the remote, again nothing.
Looked inside the red led was flashing normally which indicates the alarm is set and there is power. I tried the emergency key, the central locking worked, unlocked the car and set the alarm off. Tried to stop the alarm but the car didn’t respond at all and it was keep sounding loudly and shortly after it made these dying noises, then back to normal loud sounds again. I then jumped in and started the car all ok but then key not detected on dashboard message appeared. Left the car in ready mode for around 10 min, checked the 12v jump terminal under bonnet and showed 14.4v charging and after switched off 12.54v which means Battery is ok. Checked the key Battery showed 2.97v, hm here might be an issue. Putted a new one which measured at 3.2v but the car still didn’t recognised the both keys. They had stop workmanship so no keyless, no remote, kind of like these are not the right keys. Quick check online suggested reprogramming the keys. I did that on one of the fobs and then after both were back to normal.
Very strange, why the car decided that these aren’t her keys?! 
A bit of research about the 12v batteries in hybrids and conclusion is that AGM batteries showed be only fitted in Toyota hybrids and those had been a deep cycle batteries. Prices checked too best ones are Toyota dealer all in for £165. The idea is that if the car came out of factory with AGM the replacement Battery should  also be an AGM, same specs. 

[Dala]

This video at 18:28 shows a sheet metal for mounting a 12V car Battery. Wouldn't it be replaced with a larger metal holder ?
AGM car batteries can already be purchased for a larger size.

https://youtu.be/ZR1nsxCzwy0?t=1108

[Derek.w]

23 minutes ago, Tommy X said:

The Yaris X doesn't use a conventional stop/start system,there is no starter motor and I wonder if it is wise to deviate from the type of battery fitted as standard, just a thought.  

Just looked at the Yuasa YBX 5202 Battery its a wet Battery no mention of Not sutable for stop/start systems.

Then again NOT all stop start systems are the same IE beefed up starter motor on a petrol engine comperd to a HYBRID system where its only starting relays, computers, automatic handbrake and vacuum pump.

[Dala]

https://batteryworld.varta-automotive.com/en-gb/advantages-agm

[Derek.w]

18 minutes ago, Dala said:

This video at 18:28 shows a sheet metal for mounting a 12V car battery. Wouldn't it be replaced with a larger metal holder ?
AGM car batteries can already be purchased for a larger size.

https://youtu.be/ZR1nsxCzwy0?t=1108

I suspect you wont have room to fit a larger Battery (physical dimensions) as it will interfere with side leads & plugs for the HV Battery on top of that you are restricting its air space for cooling both batterys.

[Cyker]

1 hour ago, Derek.w said:

Cyker.

Yes I would like the answer to that one if you can just swap batterys or do the charger itself needs tobe told what type of battery it is charging or will it just work it out for itself.

As long as the cell chemistry is the same, i.e. lead and sulphuric acid and not some fancy calcium or silver etc. type, it should be fine in theory - I don't think starter-type vs deep-cycle type need different charging strategies. That said, wet cells are the most tolerant of wonky charge voltage while AGM and gel types really don't like being overvolted.

 

[Roy124]

Deep Cycle battery: my caravan Battery sat in its own plastic case with an integral charger.  At this remove I cannot remember if it was a 12v-12v or 240v-12v.  The point is it was not hit with high ampage recharging.

Toyota Hybrid: we had assumed Pb under the bonnet and AGM in the cab.  A CTEK 5 needs to have the Battery type selected. 

But - it seems the Yaris Cross has a Ca Battery and CTEK cannot advise which setting to use.

Confused of Little Snoring

[TonyHSD]

My Aldi smart charger recognising what Battery is connected to automatically but of course I can change settings to my preferences. 
Here interesting video about agm batteries.