12v battery maintenance

[Roy124]

A hie, I don't know why you think you can't use it with a Lithium Battery. 

[Derek.w]

You can use a NICO GBX55  with any 12 volt Battery but once it starts the car then unless you are doing a long run it still needs tobe re-charged via a mains charger or you be stuck tomorow again with a flat Battery.

Once you used your NICO GBX55  dont forget to re-charge as a flat Battery degrades its proformance.

[Roy124]

Just about any jumper pack should be able to start a hybrid twice.  However having done one jump start, Ready mode for one hour is recommended. 

Or connect to a charger 

 

[barriechris@aol.com]

I have owned a 2020 C_HR for about two years. Previously I have owned one hybrid Yaris, several Prius’ and an Auris. Never had a flat 12v Battery and many were left at airports whilst on holiday. Last week the car would not start and following a call to Toyota Roadside Assistance, the AA arrived and tested the Battery. The result was a voltage of 3.8v. The previous seven days amounted to approximately 800 miles, so not due to lack of use. The AA jump started the car, my main dealer had the car and tested the Battery to find it required changing. This battery is three years old on a car that has covered 32,000 miles. The dealer changed the battery under warranty at no charge to myself. Having driven Toyota hybrids for many years because they are so reliable, indeed apart from tyres and servicing never spent any money on them, they have been absolutely faultless. So, what has changed with the 12v battery. I was pleased with the services of both the AA and main dealer, but doesn’t this suggest something has changed with respect to the fitted 12v batteries now used by Toyota?

[philip42h]

3 hours ago, barriechris@aol.com said:

Last week the car would not start and following a call to Toyota Roadside Assistance, the AA arrived and tested the battery. The result was a voltage of 3.8v. The previous seven days amounted to approximately 800 miles, so not due to lack of use. The AA jump started the car, my main dealer had the car and tested the battery to find it required changing. This battery is three years old on a car that has covered 32,000 miles.

We can assume that the Battery was 'good' the previous time you started the car. So, either there has been some sort of short circuit drain or, more likely, the Battery has just 'failed'. Three years is a rather short life for a Battery but at least you now have a replacement ... 😉

[ANGIEJ]

On 5/7/2023 at 7:48 AM, philip42h said:

Perfectly OK Angie. The GBX55 is way over spec'd for our hybrids but it will do the job perfectly fine.

Just a quick question.  They recommend leaving it in ready mode !!! Is that whilst in P MODE, or in D MODE!! 
as I got mine Friday n yea I am worried bout getting stuck in car park at work!! But that would be my last nightmare as we all like to escape from our places of work !! 

[philip42h]

50 minutes ago, ANGIEJ said:

Just a quick question.  They recommend leaving it in ready mode !!! Is that whilst in P MODE, or in D MODE!! 
as I got mine Friday n yea I am worried bout getting stuck in car park at work!! But that would be my last nightmare as we all like to escape from our places of work !! 

I guess it depends on how long you expected to be parked at work, but if you drove there in the morning you would switch the car to 'off', lock the doors and the car will be fine to get away in the evening. There is no issue with the 12v Battery over a period of a few days let alone a few hours.

To have the engine charge the 12v Battery you need to be in Ready mode - which really means that you must be with your car. Parked up at home - so Ready mode and Park is just fine. But for most of us 99% of the time it would be in Ready mode and Drive while we are driving our cars - which, of course, you will be doing on your way to work and home again! 😉

Note that the engine can't charge the 12v Battery when in Neutral - so don't leave the car in Neutral. We don't need to - leave it in Drive if you are going to be stationary for a short while, or Park if you are going to be stationary for longer.

The 12v battery problem only occurs if you plan leaving the car standing for several weeks - when the jump starter is a good idea - or if there is something more seriously wrong with your car / battery .

Enjoy your new car ... 🙂

[ANGIEJ]

34 minutes ago, philip42h said:

I guess it depends on how long you expected to be parked at work, but if you drove there in the morning you would switch the car to 'off', lock the doors and the car will be fine to get away in the evening. There is no issue with the 12v battery over a period of a few days let alone a few hours.

To have the engine charge the 12v battery you need to be in Ready mode - which really means that you must be with your car. Parked up at home - so Ready mode and Park is just fine. But for most of us 99% of the time it would be in Ready mode and Drive while we are driving our cars - which, of course, you will be doing on your way to work and home again! 😉

Note that the engine can't charge the 12v battery when in Neutral - so don't leave the car in Neutral. We don't need to - leave it in Drive if you are going to be stationary for a short while, or Park if you are going to be stationary for longer.

The 12v battery problem only occurs if you plan leaving the car standing for several weeks - when the jump starter is a good idea - or if there is something more seriously wrong with your car / battery .

Enjoy your new car ... 🙂

Hiya 

I work 8 hour shifts so car is parked up for that length of time 

but my drive to work is 10 mins there n 10 mins back but 5 times a week . (Short journeys)
obviously I go out now with this car further a field of which will help 

I was a little worried as knowing others have ended up with flat batteries 

I do have the noco jump starter n a multimeter (to keep eye on the battery) I just need to see how to check Battery etc 

thank you so much for your reply as what helpful n given me peace of mind 

thank you 

[philip42h]

9 minutes ago, ANGIEJ said:

my drive to work is 10 mins there n 10 mins back but 5 times a week

... so that's 20 minutes per day, or 100 minutes per week - which is more than enough to maintain the state of charge of your 12v Battery. Toyota made the recommendation of 60 minutes per week during lock-down when our cars weren't going anywhere very much - you'll be doing way more than that!

There's nothing to worry about - enjoy your car ... 😉

[Dala]

Look at my chart.

Driving time is also not important. Modern cars do whatever they want.

[ANGIEJ]

9 minutes ago, philip42h said:

... so that's 20 minutes per day, or 100 minutes per week - which is more than enough to maintain the state of charge of your 12v battery. Toyota made the recommendation of 60 minutes per week during lock-down when our cars weren't going anywhere very much - you'll be doing way more than that!

There's nothing to worry about - enjoy your car ... 😉

Thank you so so much 

[ANGIEJ]

3 minutes ago, Dala said:

Look at my chart.

Driving time is also not important. Modern cars do whatever they want.

Oh wowww, I wonder if there’s that chart for mine 

so that’s your 12v performance of which is interesting 

I did have a look on my T but couldn’t see anything 

I’ve sussed out all other stuff n I’m currently studying the HYBRID too seeing it go up n down !! 

[Haliotis]

I realise that my C-HR hybrid Battery is of a smaller ampere/hour because it demands less loads than a conventional car BUT, if Toyota have got their sums right, should not the C-HR Battery be just as reliable as that in a conventional petrol/diesel car?  Why could not Toyota have equipped the Hybrid with a similar  ampere/hour rating as for a conventional car?  On longer journeys, fitting the smaller Battery has robbed owners of the advantage of building up more storage capacity to compensate for any subsequent short trip/long standing events which can apply due to many issues for any driver at any time.

My previous cars have all suffered  short journeys and several days standing at times, but have NEVER failed nor needed charging, and none ever replaced during my ownership of the cars.

All were VW diesels - Golf 4-years / Touran 4-years / Touran 9-years / Caravelle 5-years.  These are all factors which may cause me to avoid hybrids in the future, and go back to either petrol or diesel.  Exclusive reliance on EV does not appeal to me.

[philip42h]

46 minutes ago, Haliotis said:

Why could not Toyota have equipped the Hybrid with a similar  ampere/hour rating as for a conventional car?

Because the 12V Battery is NOT required to turn the 'starter motor' - the traction Battery is used for that.

And, to be clear, there is no issue with short journeys on a hybrid - only lack of use and excessive standing time.

[Haliotis]

2 hours ago, philip42h said:

 - only lack of use and excessive standing time.

But, if this happens with a hybrid, yet not a conventional ICE, then in my humble opinion there IS an avoidable issue.  Regardless of lower everyday demands on a hybrid’s 12 volt Battery, the ability to store energy at the same levels as an ICE car is a fundamental necessity.  Lack of use and/or excessive standing time isn’t relative to whether the owner has a hybrid or an ICE.  In reality, a hybrid could be the likely choice for an owner who does make short, infrequent journeys, but would this factor change if prospective owners were advised of the Battery failure risk before they purchased a hybrid?

However, having made this choice, I will be resolving the problem by using a suitable trickle charging unit to keep the Battery in good condition.

[ANGIEJ]

6 hours ago, philip42h said:

Because the 12V battery is NOT required to turn the 'starter motor' - the traction battery is used for that.

And, to be clear, there is no issue with short journeys on a hybrid - only lack of use and excessive standing time.

Hiya Philip, 

I’m off work for the next week n half, so I will be taking my car for a spin here n there but yesterday I put the car in ready mode for a hour n hopefully that will help .. 

they do recommend doing that too as well as taking it out 

I have a Nico jumpstart Incase of an emergency n a multimeter to check said 12v Battery !  Of which I’m yet to pluck up courage n test it.. 

Other than that my car has been ok !! I just wanna be on top of it , and avoid a situation (touch wood) 

again thank you 

 

[Martschr]

Apparently the 12v Battery isn't charged up with a alternator on a CHR hybrid its charged up by the wheels turning?  so I've just been told by a service guy at Toyota's. 

Edited July 17, 2023 by Martschr
Missed a word out

[FROSTYBALLS]

Similar topics merged.

[Bob110023]

Hyundai came up with a clever ideal. If your 12 volt Battery goes flat for what ever reason, you press a button on the dash and the hybrid Battery will jump start the 12volt Battery and away you go. 👍

[ANGIEJ]

11 minutes ago, Bob110023 said:

Hyundai came up with a clever ideal. If your 12 volt battery goes flat for what ever reason, you press a button on the dash and the hybrid battery will jump start the 12volt battery and away you go. 👍

I’ve heard that too n very clever 

[philip42h]

1 hour ago, Martschr said:

Apparently the 12v battery isn't charged up with a alternator on a CHR hybrid its charged up by the wheels turning?  so I've just been told by a service guy at Toyota's. 

That's worrying - either the service guy doesn't know what he's talking about or something got lost in translation ... 😉

There is no alternator (or starter motor as such) on a Toyota hybrid. The 12V auxiliary Battery is charged from the traction Battery via a DC-DC converter. It has nothing at all to do with whether the wheels are turning ...

The DC-DC converter is active only when the car is in Ready mode (and not otherwise).

[ANGIEJ]

7 minutes ago, philip42h said:

That's worrying - either the service guy doesn't know what he's talking about or something got lost in translation ... 😉

There is no alternator (or starter motor as such) on a Toyota hybrid. The 12V auxiliary battery is charged from the traction battery via a DC-DC converter. It has nothing at all to do with whether the wheels are turning ...

The DC-DC converter is active only when the car is in Ready mode (and not otherwise).

Hiya Philip, 

Totally agree with you, I’m waiting for the next comment !! 
“square wheels is needed to keep the 12v Battery going”

🤪😜🤪🤪

that will be the next !! 
 

take care 

[Cyker]

On 7/16/2023 at 1:39 PM, Haliotis said:

My previous cars have all suffered  short journeys and several days standing at times, but have NEVER failed nor needed charging, and none ever replaced during my ownership of the cars.

All were VW diesels - Golf 4-years / Touran 4-years / Touran 9-years / Caravelle 5-years.  These are all factors which may cause me to avoid hybrids in the future, and go back to either petrol or diesel.  Exclusive reliance on EV does not appeal to me.

Diesel 12v batteries are massive and diesel cars tend to need fewer high-draw electrics (No HV system for spark plugs) so they have big advantages with 12v batteries. The one in my Mk1 D4D was 10 years old and still started easily even in winter!

I sometimes wonder if hybrids have some sort of higher parasitic draw as they have historically been more prone to discharging the 12v, or if it's the higher usage of 12v in the car, even tho' it is being driven by the traction Battery via the DC-DC system most of the time.

Hybrids and EVs have much more electrically driven stuff than normal cars, where almost everything is driven by the crankshaft. AC compressor pump, coolant pump, vacuum pump, sometimes even oil pumps... lots of high current stuff!

3 hours ago, Bob110023 said:

Hyundai came up with a clever ideal. If your 12 volt battery goes flat for what ever reason, you press a button on the dash and the hybrid battery will jump start the 12volt battery and away you go. 👍

Absolutely - It doesn't work quite how you say*, but they really need to license/copy this from Hyundai; It's such a simple thing but so effective, and shows they are actually doing something about it rather than ignoring it for the past 10 years!

*Their system actually cuts off the 12v Battery when it drops to a certain level, before it goes flat, so there is still enough charge in it. The button just reconnects it for a short amount of time, just long enough to start the car. If you don't, it cuts off the Battery again.

They've started putting a different system in their EVs, which detects when the 12v is low, and engages the high-voltage system contactors to charge it with the traction battery, but this is fully automatic. Wouldn't work with our hybrids tho' as our traction batteries are 100x smaller than what EVs use, so the first idea would be better!!

[Roy124]

34 minutes ago, Cyker said:

I sometimes wonder if hybrids have some sort of higher parasitic draw as they have historically been more prone to discharging the 12v, or if it's the higher usage of 12v in the car, even tho' it is being driven by the traction battery via the DC-DC system most of the time.

Hybrids and EVs have much more electrically driven stuff than normal cars, where almost everything is driven by the crankshaft. AC compressor pump, coolant pump, vacuum pump, sometimes even oil pumps... lots of 

I think the recharge current on the DC DC is much less than an alternator system.  With an ICE flat Battery you don't need to run it for an hour to charge it.

I therefore suspect that the DC DC system may run in deficit if the 12v demands are at maximum. 

I had this many years ago with a SAAB 99.  Compared with the standard vehicle I had fitted a number of additional systems.   The headlights were upgraded, fog lights front and rear added, headlight wipers add,  and a radio too. 

On one dark wintery night, everything on and heater on maxi fan, the car would not start after a brief stop.

Under the right conditions your mini-12v hybrid could easily run in deficit.  Add parasitic draw over a week or so and there you are.

[Cyker]

I thought that initially, but someone said the DC-DC system can deliver something like 70-100A which should be more than enough to run everything and charge the Battery...!

That said, I think under normal circumstances, the DC-DC system doesn't run all the time and sometimes lets the Battery power all the 12v stuff when the load isn't very high. It's just a hunch as I've noticed the windscreen wipers sometimes go quickly and sometimes slowly, similar to my old cars when the engine was on or off. Also, when I start my Mk4 when it's raining, the wipers will sometimes start to move at the slower speed, then speed up significantly mid-swing, presumably as the DC-DC system comes on-line...?