12v battery maintenance, issues, etc.

[Roy124]

15 minutes ago, loz8 said:

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

I bet they don't switch off from start until end of shift.

Probably do have a secondary Battery for all the extra gear.

[Wooster]

32 minutes ago, Roy124 said:

Probably do have a secondary battery for all the extra gear....

Yes, maybe, or just a better Battery and a much larger capacity. Surrey Police have Odyssey batteries The biggest system they have in place is to be able to leave the vehicle in the 'Ready' mode but un-drivable. (You can't put it into Drive because as soon as you put your foot on the brake, it kills everything.) This way the vehicle will keep the lights flashing for hours, (with the ICE keeping the Battery charged when necessary) but no-one can nip into the vehicle and drive it away. 

[forkingabout]

2 hours ago, Wooster said:

The biggest system they have in place is to be able to leave the vehicle in the 'Ready' mode but un-drivable. 

A run lock system - vehicle cannot be driven away without the key.

[Cyker]

I wonder, if you put the car in P, will it let you take the car out of P without the key present?

 

[RabButler]

Perhaps Toyota should remove the 'Accessory' option from the Start/Stop button. That would stop all this unnecessary angst.

[Derek.w]

I wonder how the police charge the second Battery fo all there extra kit?.

[Derek.w]

N. I am using Battery monitor via bluetooth & for the last 9 or 10 weeks solar charging using 3 solar panels.

So I now for the present do not need to use mains charging it may change in the winter months only time will tell.

Today I have changed back to my Yuasa 45Ah Battery this was removed to cary out a desulphation process process that takes about 4 or 5 hours 10 weeks ago since then its used a simlar solar charging process.

Note the old MuTlu will never regain its lost capacity but it still works well with solar charging setup above.

[SDR]

I can't speak for every make/model but I never heard of an extra Battery being fitted.   Some manufacturers do 'tweak' models for emergency services and that may include larger batteries, enhanced alternators, etc..

The key is to keep the Battery charged by using what is referred to above as a run lock system.   Driver presses a hidden button, exits and locks vehicle leaving the engine running (or a hybrid in ready mode, I suppose).   If anyone breaks in, pressing the brake (auto) or clutch (manual) stops the engine.

[Pannett]

There have been some interesting and helpful comments on this topic. Our car was collected by the dealer last Friday and returned on Monday. They applied a software update to stop background software activities when the car is parked. I can't be very specific as a report was not provided on the return of the car. So far it seems better. I'm monitoring the resting Battery voltage each evening after a drive and on the morning before a drive. For example last night after a 50-mile journey it was 12.1v and this morning 11.9v. I'll update the post if any further problems arise.

[Roker]

On 5/23/2024 at 6:45 PM, 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.

Looks like the inevitable , the 12v Battery is at the end of it's life

[AndrueC]

On 6/8/2024 at 8:10 AM, W1P30UT said:

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.

I'd dispute the 'most normal use cases'. I can't remember the last time I sat in a car and listened to the radio with the engine off. I'd either get out and do whatever it is I drove there for or I'd drive off and go somewhere else.

I'm not saying it's wrong but I think you're overestimating the significance of your predicament. You are a corner case. Even worse you are apparently choosing to remain so even though several people have told you how to fix the problem.

Don't leave the vehicle in Accessory Mode. Leave it in Ready Mode instead. Problem solved.

I have never felt comfortable leaving any vehicle in Accessory Mode. I think my Dad once told me that the ignition circuits were a drain on the Battery. He was possibly wrong. But either way I've known since the 1980s that sitting in a car and listening to the radio is bad for the Battery.

I really think you're blowing this up into a bigger deal than it really is. Millions of hybrid/EV owners are happy with the current system and/or have learnt to work with it. Why can't you?

[fred88]

Used to wait in the car listening to the radio for an hour or so while the kids had various after school lessons. Mind you that was pre-hybrid days!! But I'm sure others must be in a similar position today.

On old cars I was told not to leave the ignition on because it would burn out the coil. Is there an equivalent issue with a Corolla Hybrid in Ready mode?

[Corolly Poly]

38 minutes ago, fred88 said:

Used to wait in the car listening to the radio for an hour or so while the kids had various after school lessons. Mind you that was pre-hybrid days!! But I'm sure others must be in a similar position today.

On old cars I was told not to leave the ignition on because it would burn out the coil. Is there an equivalent issue with a Corolla Hybrid in Ready mode?

No, its akin to having the engine running in a conventional ICE. The ICE will just cut in and out when the Battery needs more juice.

[Mooly]

5 hours ago, AndrueC said:

I think my Dad once told me that the ignition circuits were a drain on the battery. He was possibly wrong.

He was correct but it would depend if the old mechanical contact breaker points in the distributer were closed or not and that would depend on the position of the engine as it comes to rest. If closed a current would flow which I would estimate in the 3 amp region. Even then it would take many hours to discharge the Battery but the coil would get hot and possibly suffer in the long term.

No such issue with any modern engine hybrid or not. 

Listening to the radio with the key in accessory mode was fine as it only powered the radio. You could listen all day if you wanted without issues.

[Cyker]

On older cars Aux pretty much just powered the radio, but on modern cars the whole computer system has to be powered on, and the screen of the infotainment system alone probably uses more power than a standard single-DIN head unit!  

Some cars, esp. the bigger SUVs, have 2 12v batteries (One starter type and one caravan-esque deep-cycle/leisure type) to power the infotainment system without the engine.

 

[Mooly]

Even a modern vehicle info system should be able to be powered for many hours from a fully charged 35Ah Battery. Just think of a large screen laptop that has something like a 100Wh Battery vs the 400+Wh of even a small 35Ah car Battery. The standard laptop could run for anywhere from around 4 or 5 hours to 15 or more dependent on what tasks it was doing. On the car battery and it goes into days...

I'd bet these issues are addressed in future models as the battery technology and charge management is addressed. 

[Kieranm9091]

I am curious as to what all the fuss is about in this part of the forum.

I have just returned from a second three month stint within 12 months working abroad, leaving my car at the house. The car was driven a total of once (for 20 mins) on both occasions, and upon return the car performs as intended with no sign of the 12-V or hybrid Battery underperforming.

 

Want to know what other peoples experience are with it. I notice people being wary about leaving the car for a week or two weeks.....really? I cannot fathom why that is even a concern for the new cars.

Please enlighten me.

[Paul john]

24 minutes ago, Kieranm9091 said:

I am curious as to what all the fuss is about in this part of the forum.

I have just returned from a second three month stint within 12 months working abroad, leaving my car at the house. The car was driven a total of once (for 20 mins) on both occasions, and upon return the car performs as intended with no sign of the 12-V or hybrid battery underperforming.

 

Want to know what other peoples experience are with it. I notice people being wary about leaving the car for a week or two weeks.....really? I cannot fathom why that is even a concern for the new cars.

Please enlighten me.

I too drive a 2022 toy…

i think the underlying issue is with “connected services”

if this is enabled and always on the car has a voltage haemorrhage. 
 

mine “connected services” limited in function and shown as “trial” in mytoyota…

therefore no drain. 
 

others not so much

[Kieranm9091]

17 hours ago, Paul john said:

I too drive a 2022 toy…

i think the underlying issue is with “connected services”

if this is enabled and always on the car has a voltage haemorrhage. 
 

mine “connected services” limited in function and shown as “trial” in mytoyota…

therefore no drain. 
 

others not so much

Okay so an issue more with the newer model which has the remote A/C iirc

 

Surely leaving for a week or two weeks for a holiday isn’t a problem…and if it is, Toyota have a bigger problem.

[Paul john]

4 hours ago, Kieranm9091 said:

Okay so an issue more with the newer model which has the remote A/C iirc

 

Surely leaving for a week or two weeks for a holiday isn’t a problem…and if it is, Toyota have a bigger problem.

Many here with 2023/2024 models have reported a daily drain so yes… there may be a Toyota problem…

[Pannett]

Here is a brief update. The car was returned on 10th June after the software update and I've been monitoring the resting voltage on most days since then. The value typically drops by 0.1v overnight, which reassures me that the larger drops before the update have been fixed. I do like the car immensely, particularly the impressive performance and economy, so rejection is now off the cards. I was irritated before the fix about our Corolla because our Octavia PHEV gave us 2 1/2 years of software issues and the car should have been rejected early on in its ownership, but we liked the car so much otherwise that we hung on to it.  I'll check the resting voltage less often, wait in the car whilst my wife shops leaving it in park, carry the booster pack 'just in case' and go out a bit more. Now there is just the faulty key fob to fix, so the car is being collected tomorrow. Then my wife and I will be happy!

[Fall2684]

I’m in a situation where I’m going to leave the car parked as I’m going to be away for about 7 weeks. What should I expect of the Battery when I come back? Should I just buy a charger now so when I come back I take the Battery out and charge it in the house? Or what is the safest procedure? Is jump starting OK with these hybrids?

[ThomasL]

2019 model: you'll be fine.

If you want to be 100% certain, just disconnect the Battery. When you reconnect and drive away the car will recalibrate some of its sensors over a few meters/minutes of driving.

If the 12V ever does go too low, jump starting is fine, but then your Battery might already be damaged beyond what a recharge can properly fix (depending on what Battery tech is used - 1.8L's battery in engine bay is different to 2L's battery in the boot)

[Pannett]

Here is an update. The 12v Battery was still losing voltage, albeit more slowly. A week last Sunday we did a 260-mile journey and next day the resting voltage was 11.6v. So I called the service deoartment at our dealership and today a new 12v Battery was fitted under warranty. I'll keep on monitoring the voltage and report whether the problem has been fixed.

[W1P30UT]

An update on my car relating to the 12v issue and some other problems with the car.

 

I've successfully rejected the car within the 30 day rule, achieving a full refund, put back to a position before I purchased the car. I've now purchased a hybrid from Honda, which exhibits none of the 12v issues of the Toyota, so in my humble opinion this isn't a hybrid issue, but a Toyota issue they need to resolve with all there hybrids. I've had many happy Lexus and Toyota ownerships over the decade, but this will likely be my last for the foreseeable, which is a shame as I liked the Corolla except for it's issues. I wish you all the best with your 12v issues and getting a proper resolution from Toyota.