[chetan]

The battery died on my 4.5 year old skoda Fabia 1.2 petrol. I am not able to locate the 'ah', could somebody let me know if 36ah is sufficient or should I go with a 45ah.

How is the service of batterybhai in Bangalore ? Any reviews ?

[heysac]

Hi All,

I will need to go for a replacement for my Swift K-Series 2010 battery soon. I noticed both AC Delco and Luminous Livfast car batteries are made by Amaron but are much cheaper. Lumnious costs only about 2500 compared to Amaron for 3000. What do people think?

I am being extra careful since last time I bought Prestolite and have been having throttle body problem since which is basically body not moving enough which could be due to less startup current provided by the battery. I am not sure a battery change would cure it but might help.

Amaron article stating that they manufacture these batteries: http://www.amaron.in/privatelabel.php

[khoj]

As is typical for European makes there would be a reading on the battery stating DIN XY, wherein XY would be 40;45;60; etc and that is the rating.

OTOH, you could refer to the specifications chapter in the owner's manual which will give the alternators rating in AH for sure. A battery with rating equal to or less than the alternators rating would be suitable as long as it fits dimensionally in to the space provided.

Originally Posted by chetan

The battery died on my 4.5 year old skoda Fabia 1.2 petrol. I am not able to locate the 'ah', could somebody let me know if 36ah is sufficient or should I go with a 45ah.

How is the service of batterybhai in Bangalore ? Any reviews ?

[Sutripta]

Originally Posted by khoj

A battery with rating equal to or less than the alternators rating would be suitable

What's wrong with a larger battery?

Regards
Sutripta

[khoj]

The alternator will take a longer time to bring it up to full or required level of charge / may not be able to cope with the additional demand / may wear out prematurely. Besides the larger battery may not even fit into the space provided.

Originally Posted by Sutripta

What's wrong with a larger battery?

Regards
Sutripta

[lapis_lazuli]

Originally Posted by khoj

may not be able to cope with the additional demand / may wear out prematurely

The battery per se, will not "demand" anything more. It is reliant on how much the alternator will "gift" it with, to get "fully charged"! You were right, it might take a somewhat longer time to be "fully charged" but will definitely not wear out a previously good alternator.

[Sutripta]

Originally Posted by khoj

The alternator will take a longer time to bring it up to full or required level of charge / may not be able to cope with the additional demand / may wear out prematurely.

If we start from a known SoC, say fully charged, there will be no difference time wise. Think of the battery as a reservoir of charge, from which we withdraw, and replenish charge. Bigger will actually be better (though not weight or cost wise). And both battery and alternator will be in fine fettle.

Originally Posted by lapis_lazuli

You were right, it might take a somewhat longer time to be "fully charged" but will definitely not wear out a previously good alternator.

Even if you start off with an almost dead battery, topping up is a one time thing. After that battery size makes no difference, in the context of this discussion.

Regards
Sutripta

[lapis_lazuli]

Originally Posted by Sutripta

If we start from a known SoC, say fully charged, there will be no difference time wise.

Quite evident. Obvious actually.

Think of the battery as a reservoir of charge, from which we withdraw, and replenish charge.

Umm well, almost. In practice it is a bit different.

Bigger will actually be better (though not weight or cost wise). And both battery and alternator will be in fine fettle....no difference

Yes and NO. In certain cases (cannot put an exhaustive list here), say, where a car does excessive start stop trips, too many cranks and less travel, effectively leaving the battery in perpetual "need for top up" or in plain words, partially charged over an extended period of time, can be detrimental to the limited life and health of the "bigger" battery. For sure, in no case will the alternator feel any heat!

https://www.princeton.edu/~spikelab/papers/101.pdf

Slightly OT, but since you study and think quite a bit, the above can be a good read.

Context

What context???

[Sutripta]

Originally Posted by lapis_lazuli

What context???

Replacement of OE battery by bigger battery.

The OE battery is going to be the cheapest battery the manufacturer could get which meets his criteria. In case of SIL batteries, that effectively means meeting CCA requirements. The bigger replacement is unlikely to be more than ~10% bigger. (The cheapest etc. part also applies tyres. Which lots of people promptly change/ upsize on buying a new car)

Umm well, almost. In practice it is a bit different.

Talking of factors which influence charge acceptance, or something else? If something else, pls. don't keep us in suspense!

Yes and NO. In certain cases (cannot put an exhaustive list here), say, where a car does excessive start stop trips, too many cranks and less travel, effectively leaving the battery in perpetual "need for top up" or in plain words, partially charged over an extended period of time, can be detrimental to the limited life and health of the "bigger" battery.

If the batteries have similar chemistries and construction, I would say if one battery is going to be partially charged, so would the other. Only difference is that the smaller battery is going to be cycled deeper.

Slightly OT, but since you study and think quite a bit,

And when did you come to that conclusion? (Because I got the distinct impression that first time we interacted, you thought me to be a moron who did not know what he was talking about. (Mind you, the moron part, and the not knowing what I'm talking about part might be the correct evaluation ... ))

Regards
Sutripta

[lapis_lazuli]

Originally Posted by Sutripta

The bigger replacement is unlikely to be more than ~10% bigger.

OK. Agree. Was not as evident earlier.

Talking of factors which influence charge acceptance, or something else? If something else, pls. don't keep us in suspense!

Quite there. See, consider 2 buckets, reservoirs. One empty, the other filled to the brim. You could fill the empty one using a small mug, dipping and decanting 50 times from the filled one, or you could instantly fill it up by decanting the filled bucket itself. So, charge(fill up) and discharge(decant) could be virtually near instantaneous or slow; governed by the user/demand.

While for the battery, nopes. While you "could" discharge near instantaneously, charge instantly : NEVER. (For capacitors, yes to a certain degree.) In the battery it is the conduction current PLUS the inertia of the chemical process, while for the capacitor reservoir, it is something called the displacement current! There is no conduction current at all. ( I had to bring in the capacitor part.)

If the batteries have similar chemistries and construction, I would say if one battery is going to be partially charged, so would the other.

Yes to varying degrees of SoC; on the same scale, at different notches. But what you say, is not a conclusive statement. Let us understand. The culprit is the temperature inside the bay. The bigger battery, (for sure not a ~10% uprated one), would kick the bucket much earlier. I would say, even a 20% uprated model, is calling for premature failure. The damage starts from the first partial charge event onwards, and quick rise to 80 degrees at the plates makes it worse! The depth of discharge and subsequent partial charge "sensitivity" is greater for the battery with larger surface area of plates. (Sulfation model kicks in now) That somebody (or some thousand people) was lucky with his batteries, is no ground for disproving a menace plaguing the relevant industry!

We have actually spent 3 years characterizing to arrive at a reliable "gas gauge" algorithm for battery life prediction. Simple coulomb counting fails here. You could look at the mathworks paper on battery modelling. It is quite popular in the industry. It is also surprising that we take it for granted that a 3--4 year life time of a battery in a car or 2 years at home is enuff! What gross misuse!!!

And when did you come to that conclusion? (Because I got the distinct impression that first time we interacted, you thought me to be a moron who did not know what he was talking about. (Mind you, the moron part, and the not knowing what I'm talking about part might be the correct evaluation ... ))

Irrelevant and I sense latent anger and/or sarcasm..

On a lighter note, you often throw profound questions, but actually answer them only on rare occasions. Often, questions for which you already have the best answers by virtue of experience, experiments or exemplary knowledge. Not sure.

We are going off topic. While your badge ensures you are immune to wrath, I am not!

Good night. I would like to meet with you some day. I am quite curious!

[Sutripta]

Originally Posted by lapis_lazuli

Quite there. See, consider 2 buckets, reservoirs. One empty, the other filled to the brim. You could fill the empty one using a small mug, dipping and decanting 50 times from the filled one, or you could instantly fill it up by decanting the filled bucket itself. So, charge(fill up) and discharge(decant) could be virtually near instantaneous or slow; governed by the user/demand.

Can't quite make out the point you are trying to make here.

Yes to varying degrees of SoC; on the same scale, at different notches. But what you say, is not a conclusive statement. Let us understand. The culprit is the temperature inside the bay. The bigger battery, (for sure not a ~10% uprated one), would kick the bucket much earlier. I would say, even a 20% uprated model, is calling for premature failure. The damage starts from the first partial charge event onwards, and quick rise to 80 degrees at the plates makes it worse! The depth of discharge and subsequent partial charge "sensitivity" is greater for the battery with larger surface area of plates. (Sulfation model kicks in now) That somebody (or some thousand people) was lucky with his batteries, is no ground for disproving a menace plaguing the relevant industry!

It would be interesting to look at the models you are using, if you can share them. (I do know those are likely to be actually proprietary. Unlike the nondisclosure cover some people take shelter under.)

We have actually spent 3 years characterizing to arrive at a reliable "gas gauge" algorithm for battery life prediction. Simple coulomb counting fails here. You could look at the mathworks paper on battery modelling. It is quite popular in the industry. It is also surprising that we take it for granted that a 3--4 year life time of a battery in a car or 2 years at home is enuff! What gross misuse!!!

I think we all know about the pitfalls in designing a SoC/ SoL gauge for a battery.

Irrelevant and I sense latent anger and/or sarcasm..

A quiet chuckle actually.

On a lighter note, you often throw profound questions, but actually answer them only on rare occasions.

Think we'll use the tag "profound" for matters involving love, life, and death.

Normally asking a question is enough to get a discussion back on track (or at least the track I think it should be on). And I can then disappear back into the background.
Other times my posts are in the nature of a private conversation in a public room (eg. this conversation. It is between you and me, but held in a public forum). And if the other party to the dialogue stops responding, so do I.

We are going off topic. While your badge ensures you are immune to wrath, I am not!

No such thing!
You would be surprised at the number of posts of mine which have been deleted.

Regards
Sutripta

[lapis_lazuli]

Originally Posted by Sutripta

Can't quite make out the point you are trying to make here.

Various type of reservoirs : the easy reservoir, and the "sluggish" reservoir (the battery)! I had mentioned elsewhere, about it being a "bit different" IIRC.

I think we all know about the pitfalls in designing a SoC/ SoL gauge for a battery.

Whoa! Is the understanding of the ACTUAL underlying problems, as trivial?

On the other hand, in case of a misinformed/generalized, emotional opinion, joke, or a scorn, as in "we all know", I have to disagree, and earnestly request all such readers, to first accept that there could be concepts deeper than PopSci comprehension, then dive a little deeper.

Think we'll use the tag "profound" for matters involving love, life, and death.

Entirely your (their) choice.

Quoting Bill Clancey et al from their book "Contemplating Minds A forum for Artificial Intelligence"

"too many profound technical questions are still open..."

Nobody corrected them, I don't stand corrected either!

Regarding the models you requested: the references in the Mathworks paper I mentioned above, and the paper itself, will be quite exhaustive and enlightening.

[Sutripta]

Originally Posted by lapis_lazuli

Various type of reservoirs : the easy reservoir, and the "sluggish" reservoir (the battery)! I had mentioned elsewhere, about it being a "bit different" IIRC.

Of course analogies have their limits. Just like models.

Whoa! Is the understanding of the ACTUAL underlying problems, as trivial?

Have I said it is trivial? Trivialising holy grails is sacrilege!

Entirely your (their) choice.

Quoting Bill Clancey et al from their book "Contemplating Minds A forum for Artificial Intelligence"

"too many profound technical questions are still open..."

Omniscient Google tells me it is in reference to somebody elses thoughts on technology and its interaction with society.
Totally totally OT, can you list a couple of purely technical questions on this forum which you would consider profound?

On the other hand, in case of a misinformed/generalized, emotional opinion, joke, or a scorn, as in "we all know", I have to disagree, and earnestly request all such readers, to first accept that there could be concepts deeper than PopSci comprehension, then dive a little deeper.

I tell others not to do so! Show me one place (in the context of my 3000+ posts on this forum) where I have done so!

Regarding the models you requested: the references in the Mathworks paper I mentioned above, and the paper itself, will be quite exhaustive and enlightening.

Will take a look when I have some time (Puja holidays maybe).
In the meantime I take it that this is the crux of your argument:
The bigger battery will have the shorter life because other things being equal, it will run hotter. Have I understood you right?

Regards
Sutripta

[lapis_lazuli]

Originally Posted by Sutripta

Crux...argument....The bigger battery will have the shorter life because other things being equal, it will run hotter. Have I understood you right?

Regards
Sutripta

For benefit of other readers:

"Bigger battery, shorter life, all other conditions identical": An emphatic Yes, in cases of repeated sub-optimal charge replenishment (one of the main causes), that too, while being simultaneously exposed to high ambient temperatures (aiding the earlier cause in brackets) in the engine bay, whence the cumulative degradation is more pronounced.

What do you mean by "it will run hotter?" Being exposed to high ambient temperature in its day to day life? HEAT is another CAUSE to the effect of degradation.

I have tried to summarize in a single sentence here, though I find it difficult to believe you interpreted the facts in your last post, the way you project it to be. Sophisticated trolling?

Good night!

[Sutripta]

^^^
So if I've understood it properly this time, the bigger battery will have a shorter life because
a) the (engine/ battery) bay temperatures will be higher (won't make the mistake of saying battery will run hotter),
and
b) the battery will be 'suboptimally' charged.

Trolling part:- leave for others to come to their own conclusion.

Regards
Sutripta