Thanks for the correction, would the same be said for a petrol or diesel tank?

 

Do they generate energy or simply convert it? Is it not the alternator generating the energy? Answering my own question that is actually converting rotational force created by combustion.

 

I agree with the self discharge and made mention of it a few times, 30 years ago it was the only thing affecting how long a car could remain unused and still restart, now it is de minimus compared to the parasitic discharge of the cars electronic systems.

2 hours ago, J.R. said:

Thanks for the correction, would the same be said for a petrol or diesel tank?

 

Do they generate energy or simply convert it? Is it not the alternator generating the energy? Answering my own question that is actually converting rotational force created by combustion.

 

I agree with the self discharge and made mention of it a few times, 30 years ago it was the only thing affecting how long a car could remain unused and still restart, now it is de minimus compared to the parasitic discharge of the cars electronic systems.

The chemical reaction occurs in the engine, the fuel tank simply stores the potential energy.

But to get back on topic, the OPs battery is very likely to lose up to 25% of initial charge, purely from self-discharge over four months - add to that the quiescent load to the various electronic modules (quite possibly the same) and bearing in mind the battery probably only being 75-80% charged, maximum, (due to the smart alternator control) at the start of the layup, it is conceivable that the SOC could drop to around 30%, even with a battery in perfect condition.

Lead acid battery lifespan can be significantly reduced if kept at a low state of charge.  

Edited 8 December, 20241 yr by Warrior193
typo

In answer to the question does the alternator generate the energy? - no, it doesn't directly - it acts to reverse the chemical reaction the battery cells undergo on discharge.

The chemical composition of the cell plates is changed between charged and discharged state. 

Edited 8 December, 20241 yr by Warrior193
typo

1 hour ago, Warrior193 said:

But to get back on topic, the OPs battery is very likely to lose up to 25% of initial charge, purely from self-discharge over four months - add to that the quiescent load to the various electronic modules (quite possibly the same) and bearing in mind the battery probably only being 75-80% charged, maximum, (due to the smart alternator control) at the start of the layup, it is conceivable that the SOC could drop to around 30%, even with a battery in perfect condition.

Lead acid battery lifespan can be significantly reduced if kept at a low state of charge.  

 

A very good summary 👍

9 hours ago, sussamb said:

Stop/start batteries only 'take a beating' as you put it if you allow them too, plus the system puts more strain on starter motor etc,  it's why i always switch it off before I drive off!

 

I turn it off for shorter journeys as I don't like a cold engine being cranked ten times in the space of 5 minutes. Once it's warm I usually turn it on, as I like saving some petrol. 

 

Starting the car requires a lot of current draw. If the battery is not adequately charged, it is very cold, etc, then the engine stop/starting will put even more strain on the battery. Even when using it normally, the constant cranking of the engine with the rest of the car's systems being on (unlike when on the drive) still strains the battery. Imagine sitting at the lights with a/c, digi dash, lights, music, and everything else that's on. Yes, EFB and AGM batteries are better designed to combat this, but the point remains. Stick a normal battery in a start/stop car and see how long it lasts!

 

Bottom line - yes, modern batteries are more efficient and resilient than older ones, however using start/stop does put more strain on the battery and shorten its life. Fact.

 

Note - doesn't include the start/stop systems that stop the engine just before a cylinder fires, and then restarts the engine by firing it.

 

I was very surprised that keeping the doors open for most of the day (interior lights turned off, etc) killed my battery. Okay, it probably wasn't the healthiest to begin with, but the car is only three/four years old. The parasitic draw in modern cars is insane, all this keyless entry stuff, etc. There's a reason it's only electric cars that have those sentry mode cameras!

46 minutes ago, Occy245 said:

 

I turn it off for shorter journeys as I don't like a cold engine being cranked ten times in the space of 5 minutes. Once it's warm I usually turn it on, as I like saving some petrol. 

 

Starting the car requires a lot of current draw. If the battery is not adequately charged, it is very cold, etc, then the engine stop/starting will put even more strain on the battery. Even when using it normally, the constant cranking of the engine with the rest of the car's systems being on (unlike when on the drive) still strains the battery. Imagine sitting at the lights with a/c, digi dash, lights, music, and everything else that's on. Yes, EFB and AGM batteries are better designed to combat this, but the point remains. Stick a normal battery in a start/stop car and see how long it lasts!

 

Bottom line - yes, modern batteries are more efficient and resilient than older ones, however using start/stop does put more strain on the battery and shorten its life. Fact.

 

Note - doesn't include the start/stop systems that stop the engine just before a cylinder fires, and then restarts the engine by firing it.

 

I was very surprised that keeping the doors open for most of the day (interior lights turned off, etc) killed my battery. Okay, it probably wasn't the healthiest to begin with, but the car is only three/four years old. The parasitic draw in modern cars is insane, all this keyless entry stuff, etc. There's a reason it's only electric cars that have those sentry mode cameras!

The reason for your battery failing when you left the door open, interior lights off, will be because the various electronic modules etc. were prevented from going into 'sleep mode' - the resultant current draw is much higher then. 

1 minute ago, Warrior193 said:

The reason for your battery failing when you left the door open, interior lights off, will be because the various electronic modules etc. were prevented from going into 'sleep mode' - the resultant current draw is much higher then. 

 

Yes, of course. My point was I didn't expect that to kill the battery - strain/drain it yes, but not kill it. Clearly, it shows the sheer amount of draw that all these modules draw from the battery. I was very careful to make sure the digi dash was off, etc, but the battery didn't like it either way. 

Yes I have been caught out like that before, in the past leaving sidelights on overnight would flatten the battery although a new one would usually restart the vehicle the next morning, recharging it would bring it back to full health, my brand new Bosch battery was mortally wounded through doing that and not even overnight, it charged but the electronic tester showed it at something like 60% capacity, it had been at 100%, its cell voltage after charging is less than my old standby batteries. It was as you say the high discharge from all the active modules.

 

I'm still using it a couple of years later but can't expect a lot from it now.

 

My car times out the interior lights if I leave a door open, it does the same if I switch off leaving the headlights on, I don't lock the car at home so it takes longer for the modules to go to sleep, the shut off timer does not work on the sidelights though, I guess because you would use them to alert oncoming traffic if you left the car after a breakdown to get fuel or help.

 

Edited 8 December, 20241 yr by J.R.

Guys, do what I do and just use your car normally.  It involves just using your car normally🤷🏻‍♂️

 

If that means not using your car for days on end, or using it every single day then so be it, you’ll probably find that you have zero battery issues either way.

 

I do, have done for as long as I can remember, no issues whatsoever.

 

Threads like this literally twist my melon man🤷🏻‍♂️😂😂

Edited 8 December, 20241 yr by carefree

The OP has been unable to use his car normally due to health issues for 3 months and the non use will continue for at least another month hence him asking for advice.

 

One persons normal will be different to another.

 

I am surprised that someone asking for and receiving advice on a car forum should trigger you.

8 minutes ago, J.R. said:

The OP has been unable to use his car normally due to health issues for 3 months and the non use will continue for at least another month hence him asking for advice.

 

One persons normal will be different to another.

 

I am surprised that someone asking for and receiving advice on a car forum should trigger you.

Hahaha brilliant.  I’m nowhere near triggered mate, just telling you how it is.  A modern battery should NOT struggle after 3 months out of use.  If you/ anyone thinks otherwise then you need your heads wobbling/ 

or you have no experience of cars whatsoever.

 

Aside from anything else, what’s it got to do with you?  Wind your neck in🙄😂😂

 

 

Edited 8 December, 20241 yr by carefree

'Should not'. 

Exactly, but plenty modern batteries do struggle after 3 months out of use.  Or 2-3 weeks at a airport long stay car park.

Maybe because of their age. But not always.

Just a fact that you see at Dealerships when they need a Boost, as at auctions where a car might be only a few days sitting from coming off a transporter. 

 

RAC / AA ? Greenflag and other responders out jumping cars, changing batteries just because someone somewhere was that poor sod with 'No experience of cars whatsoever'.

 

They just imagined it, internet myth. 

Edited 8 December, 20241 yr by Ootohere

6 minutes ago, carefree said:

Hahaha brilliant.  I’m nowhere near triggered mate, just telling you how it is.  A modern battery should NOT struggle after 3 months out of use.  If you/ anyone thinks otherwise then you need your heads wobbling/ 

or you have no experience of cars whatsoever.

 

Aside from anything else, what’s it got to do with you?  Wind your neck in🙄😂😂

 

 

 

With some impartiality, you could take your own advice... You comment on a post specifically about an abnormal occurance, and your advice is to be normal - really great, valued and considered input.

 

As JR says, the OP has left the car for autumn and half of winter without starting it. While I think it will start, I personally would charge it a bit first as I suspect it will have a low SoC. I wouldn't be suprised if it doesn't. 

 

Most dealerships trickle charge their cars and they are quite literally brand new. Most supercars trickle charge and their batteries are quite modern.

To the op ,chances are your car will start after being stood ,but if you have a smart charger to trickle charge and keep battery topped up then you know all will be good 👍

Edited 8 December, 20241 yr by Mickvrs220

52 minutes ago, Ootohere said:

'Should not'. 

Exactly, but plenty modern batteries do struggle after 3 months out of use.  Or 2-3 weeks at a airport long stay car park.

Maybe because of their age. But not always.

Just a fact that you see at Dealerships when they need a Boost, as at auctions where a car might be only a few days sitting from coming off a transporter. 

 

RAC / AA ? Greenflag and other responders out jumping cars, changing batteries just because someone somewhere was that poor sod with 'No experience of cars whatsoever'.

 

They just imagined it, internet myth. 

As I’ve said, the many cars I’ve owned over the last two decades have NEVER had a battery issue.  You can give me all the in depth scientific evidence you like, fact is in my experience it’s either rarer than rocking horse sh!t or a total myth.  Your choice🤣

53 minutes ago, Occy245 said:

 

With some impartiality, you could take your own advice... You comment on a post specifically about an abnormal occurance, and your advice is to be normal - really great, valued and considered input.

 

As JR says, the OP has left the car for autumn and half of winter without starting it. While I think it will start, I personally would charge it a bit first as I suspect it will have a low SoC. I wouldn't be suprised if it doesn't. 

 

Most dealerships trickle charge their cars and they are quite literally brand new. Most supercars trickle charge and their batteries are quite modern.

You don’t have to value it or consider it mate, it couldn’t care less either way.  Just know that in well over 20 years and probably 10 different cars I have never once had a battery issue.  It’s a lived experience mate, but you go

with what you go with 🙄🤣🤣

8 minutes ago, carefree said:

As I’ve said, the many cars I’ve owned over the last two decades have NEVER had a battery issue.  You can give me all the in depth scientific evidence you like, fact is in my experience it’s either rarer than rocking horse sh!t or a total myth.  Your choice🤣

They’re probably too scared to give any issues in case you start talking.

 

Nobody is saying not having issues is impossible - but I don’t know anyone that hasn’t had at least one flat battery at SOME point.

 

Not to mention, for the third time, that you likely haven’t left your car for four months in winter without starting it.

 

Please, don’t just take it from me - take the hint from the other members’ reactions to your posts…

 

Your opinion is your opinion, whatever it may be, but there is no need for the sarcasm or the attacking of other members. In this instance, you are offering absolutely nothing, except confusion for the OP and others to sift through.
 

It’s like you’re commenting on a post on Enyaq charging issues, and you come along commenting that you’ve never had a problem on your numerous ICE cars. Your famed ‘lived experience’ is completely irrelevant - you just can’t see it.

Edited 8 December, 20241 yr by Occy245

They?  Who’s they?

 

Mate, I’ve been driving cars since 1988 and I can categorically tell you that not once have I had a battery issue.  Maybe certain people don’t know how to drive/maintain cars, who knows?

 

Oh, and for the second time I HAVE left my car for almost 4 months over a freezing winter, and it started first time without issue.  
 

Confusion?  No mate, I merely stated that in all the years I’ve been driving I have NEVER once encountered a battery issue.  You call that confusion?  Jesus🤣
 

Frankly, this is boring me now🙄🤣🤣

Edited 8 December, 20241 yr by carefree

26 minutes ago, carefree said:

They?  Who’s they?

 

Mate, I’ve been driving cars since 1988 and I can categorically tell you that not once have I had a battery issue.  Maybe certain people don’t know how to drive/maintain cars, who knows?

 

Oh, and for the second time I HAVE left my car for almost 4 months over a freezing winter, and it started first time without issue.  
 

Confusion?  No mate, I merely stated that in all the years I’ve been driving I have NEVER once encountered a battery issue.  You call that confusion?  Jesus🤣
 

Frankly, this is boring me now🙄🤣🤣

 

I'm sure you're able to see. Equally, if it's boring you, then why reply to the thread?

 

It brings all of us great joy to hear that you've not had an issue since 1988 - you must be very special and know exactly what you're doing! It's very impressive to read that you, with your ten different cars, have all managed to beat the simple physics of electrons and ions.

 

Every other person on this thread has said, correctly, that it would likely be best to put a charger on the OP's battery for a little bit. You then comment, dripping with self-righteousness, about how 'any half decent battery' will be fine and that it is 'OP's money', failing to read that the OP already has a battery charger. Doh!

 

You then argued that a modern EFB or AGM battery can't be compared to an old lead acid one. You're correct - it can't. However, the parasitic draw of a modern car also can't be compared to an Austin Allegro. Fear not though, you are quick to bring rocket science to the party - failing once again to understand that developments in battery technology haven't beaten physics. It is true that batteries are more advanced now, however modern cars are significantly more advanced.

 

Upon being met with this abundance of scientific reality, you then tell someone to 'wind their neck in', for no obvious reason?

 

As @J.R. said - "Your vehicle restarting after a 4 day shift pattern does not mean you can say that the OP is taking completely unnecessary precautions when his vehicle will be standing unused for 4 months!".

 

I don't think any of us understand why some simple, best practice advice, has to turn into a competition over 'in my vast experience I've NEVER had a problem, blah, blah, blah'. We are simply suggesting that the OP should use his charger for a bit before starting, as it will likely mitigate any risk of over straining the battery. Even if you're right and we are all wrong, what's the OP lost? Ten minutes of his time and about 5p of electricity.

 

I'm quite new to the forum and must say, for someone that is so 'carefree', the history of your crushingly righteous comments on posts seems quite antagonistic and unpleasant. 

You have a carefree way with words, it's called the wrong way

 

Speaking for myself I am not your "mate" and sympathise with those who are.

 

@Occy245 The moderators intervened earlier to remove the worst of the insulting comments, I think its best to leave the contributor to have the last word.

Edited 8 December, 20241 yr by J.R.

9 minutes ago, J.R. said:

You have a carefree way with words, it's called the wrong way

 

Speaking for myself I am not your "mate" and sympathise with those who are.

 

Yes, I took offence at that too, but didn't want to spoil his illusion of a blossoming friendship. He must have a hard time reading the room over an internet forum.

 

@J.R. I agree, I just don't like not saying anything when people are so unreasonably rude. It's probably best not to engage, but then again, I was born on this side of the millenia!

 

TLDR - @RallySimon I wish you a speedy recovery. Pop a charger on the battery at some point, and you should be absolutely fine!

Edited 8 December, 20241 yr by Occy245
Update/Reply

8 hours ago, Occy245 said:

 

I'm sure you're able to see. Equally, if it's boring you, then why reply to the thread?

 

It brings all of us great joy to hear that you've not had an issue since 1988 - you must be very special and know exactly what you're doing! It's very impressive to read that you, with your ten different cars, have all managed to beat the simple physics of electrons and ions.

 

Every other person on this thread has said, correctly, that it would likely be best to put a charger on the OP's battery for a little bit. You then comment, dripping with self-righteousness, about how 'any half decent battery' will be fine and that it is 'OP's money', failing to read that the OP already has a battery charger. Doh!

 

You then argued that a modern EFB or AGM battery can't be compared to an old lead acid one. You're correct - it can't. However, the parasitic draw of a modern car also can't be compared to an Austin Allegro. Fear not though, you are quick to bring rocket science to the party - failing once again to understand that developments in battery technology haven't beaten physics. It is true that batteries are more advanced now, however modern cars are significantly more advanced.

 

Upon being met with this abundance of scientific reality, you then tell someone to 'wind their neck in', for no obvious reason?

 

As @J.R. said - "Your vehicle restarting after a 4 day shift pattern does not mean you can say that the OP is taking completely unnecessary precautions when his vehicle will be standing unused for 4 months!".

 

I don't think any of us understand why some simple, best practice advice, has to turn into a competition over 'in my vast experience I've NEVER had a problem, blah, blah, blah'. We are simply suggesting that the OP should use his charger for a bit before starting, as it will likely mitigate any risk of over straining the battery. Even if you're right and we are all wrong, what's the OP lost? Ten minutes of his time and about 5p of electricity.

 

I'm quite new to the forum and must say, for someone that is so 'carefree', the history of your crushingly righteous comments on posts seems quite antagonistic and unpleasant. 

I read the first few words and then gave up mate, beyond boring.🥱

8 hours ago, J.R. said:

You have a carefree way with words, it's called the wrong way

 

Speaking for myself I am not your "mate" and sympathise with those who are.

 

@Occy245 The moderators intervened earlier to remove the worst of the insulting comments, I think its best to leave the contributor to have the last word.

Don’t be like that mate.

8 hours ago, Occy245 said:

 

Yes, I took offence at that too, but didn't want to spoil his illusion of a blossoming friendship. He must have a hard time reading the room over an internet forum.

 

@J.R. I agree, I just don't like not saying anything when people are so unreasonably rude. It's probably best not to engage, but then again, I was born on this side of the millenia!

 

TLDR - @RallySimon I wish you a speedy recovery. Pop a charger on the battery at some point, and you should be absolutely fine!

Brilliant😂😂

@carefree just for clarity about where your various cars over the years sit for however long in what ever weather, where are you in the UK?

Is it possibly in the milder southern part of the UK?

 

I never have battery issues and have not had for 5 decades and hundreds of old cars and new cars, other than with a Volvo S60 & 4x4 automatics that really need big batteries to start and require a boost if sat awhile, and once with a brand new Hyundai i30 that could not sit unused for a week.

Every vehicle i have had is an automatic, and i have traded in cars and repaired them since i was at school.

I have assisted plenty jump starting or boosting cars over the years with all sorts of vehicles,

Edited 9 December, 20241 yr by Ootohere