How long should a battery last?

"Burgerman" gurgled happily, sounding much like they were saying:

What, by running 'em flat every day for a couple of months?

No 80 percent average odd day at 90 percent discharged.

Definition of a deep cycle battery

They managed 30 cycles, or a month. Charged every morning with a 5 stage purpose built EV vehicle charger. Measured and state of charge tested after each 8 hour night disconnected and logged as usual.

Optimas, hawkers, oem fitted Sonnenchiens all maneged to do the 300 plus much more in some cases as they are real deep cycle batteries. The halfords ones were sticker only. They performed only slightly better than a starter battery would be expected to do. 10+ times shorter lived...

"Burgerman" gurgled happily, sounding much like they were saying:

Lovely, an' all.

But - and this is the point you seem to be completely failing to grasp - completely and utterly irrelevant to use in 99%+ of cars.

No this was in response to battery warranties and in particular halfords!

Honouring a warranty usually means replacing once. If all their products needed replacement several times during the warranty they'd soon be out of business - so I'd say it's only fair they questioned the abuse of the product.

I'm not sure I'd take Halfords word for anything. ;-)

I'd say they were operating on the same principle as B&Q with their power tools and long warranties - the majority who buy such things simply don't use them enough to wear them out within that time. So the overall high sales pays for the odd one who does.

As I said, you don't usually get a bargain by buying the cheapest.

Err, since you claim to be such and expert and Optima are perfect why didn't you stick with them?

Apart from the cost.

The point I was making is that in normal use (in a car) a quality car battery will last just as long and not give any problems. For about a third of the price.

FWIW I use all types of batteries in my job as a sound engineer. Including lead acid (SLA) to run video monitors. These don't have a high current demand - but do tend to get run 'flat'. In an ideal world they'd get changed on a time basis so they were only ever partially discharged - but life isn't that organised. I tend to use whatever is the best value at the time from places like CPC or RS and haven't really found much difference in life. And yes, I have tried Optima. And didn't find them value for money in that case either.

One day when you are a bit older you will realise that its the least important consideration. And some othe less good batteries cost more. If you are destitute or jelous of those that want them then yes its an issue...

Will cost the same! There are a good few in this sector...

will last just as long and not give any problems. For about a

No it wont. For two thirds the price there are a few pretenders but no trr shirt.

But with heavy current demand in the heavy hundreds of amps the capacity becomes irrelivant since its like the starter has the same resistance as the cheap battery! Especially as charge level drops.

In an ideal world they'd

Well unless taking huge currents optimas wont perform better than a cheap deep cycle. But this thread was about engine starting where internal resistance determines performance above all else.

So I still dont think you got it.

You seem to have introduced about every other possible use in your bid to promote Optima.

I dont promote them and havent sold them in years. They are not even particularly expensive though compared to the equivelent AGMs from the likes of Varta or Hawker (cheaper in many cases while being superior in specs.)

I am just explaining to those that are a bit dim when it comes to batteries why they are better but its not possible with everybody..

You seem to be taking much longer than others to understand. My GF teaches kids maths. She has the same problem with some of them. Not all kids are created equal apparently and some never will get it.

"Burgerman" gurgled happily, sounding much like they were saying:

Bollocks. Your entire participation in this thread is a sales pitch.

No, you're coming up with a whole bunch of irrelevancies to try to justify why they're "better" for Joe Public. Which they aren't.

Sounds that way but its not true. I have nothing to gain.

They are provably and demonstrably better in all physical and electrical ways compared to a standard starter battery. So they ARE better. You may not like that but its true. Try and match the specs with something else cheaper, and you cant.

The only argument that any logical (counts you and dave out) person can have is is it worth the expense for them? Or can they afford it.

Indeed. And you don't appear to have convinced anyone. And rightly so - as I said they're a con for a normal car. I'm really not concerned with other uses here.

You seem to miss the point entirely.

As apparently did your GF with her flat ordinary battery. Still, you'll know what to give her for Xmas. So romantic.

Do they make the car perform better? Save fuel? Improve the handling? Make it look better or more comfortable? Sound better? No?

The makers spec the battery for a car - not some so styled amateur expert. If they reckon it needed a better spec then I'm pretty certain the upmarket ones would do so. Like they do with tyres.

Which brings me back to my original point you simply can't accept. They are an unnecessary expense for an ordinary car - therefore by the advertising on that site you wrote, a con.

Mony a mickle maks a muckle, as they say.

Yep! When it wont go because someone left something plugged in or because it failed early due to its electrical characteristics, OETC.

Well since you asked then yes. Probably not much but its lower internal resistance means more efficient recharge after starting.

Its lighter...

Make

Looks better than with jump leads attached!

Yes that flat battery sound is pretty bad...

Yes.

They spec something thats suitable yes. At a price.

Why do you think people bother to modify cars? To fit better ICE, tyres, batteries, etc etc...

The upmarket ones DO DO SO.

Many up market cars already have a stock AGM battery fitted as standard.

There is no con other than in your miind. If you want a better battery you have to pay for it. And I have repeatedly explained quite clearly why its better but you seem to dim to understand it. And Optimas are no more expensive than any other AGM battery.

That makes about as much sense as you do.

Have you any proof this saves energy - or is it just another wild claim?

It's science, isn't it. The internally wound "spiral" technology inside the battery acts like a Helter-Skelter for the electrons. That's where the reduced internal resistance comes from. Also, because they're moving so much faster (assisted by Gravity), they make a much bigger bang when they come out of the battery - stands to reason. They're going faster so they have more energy.

Richard

Well if you had even a tiny grasp of physics you wouldnt need to ask such a stupid question.

So I will now give you a school kid level physics lesson since you obviously still dont seem very good at logic or physics.

I already told you the answer in dozens of posts that you choose to ignore. So here goes yet again.

Take your cheap low CCA and high resistance crappy battery and turn the key. The battery voltage typically drops from 12.7 fully charged to around 8v to

Do the same trick with an AGM high CCA (therefore low internal resistance) battery like Optima, hawker, Varta, or any others and you get much less volt drop. This does 2 things.

a) it spins your motor over faster giving faster starts (yes even when almost discharged!) so less wasted current. But ignoring this: b) it means much less energy WASTED heating up the battery.

Now once started that energy needs to be replaced by the alternator. And again we have several reasons why a lower resistance high CCA battery (actually the same thing)is better and more efficient.

a) the battery charges faster (lower internal resistance works both ways - charging and discharging efficiency) c) less wasted energy while charging due to heating the battery due to the same low internal resistance d) less energy needed to be put back anyway since we didnt wast much in heating up the battery due to its voltage drop/resistance when starting.

Now I dont expect this will add up to much saving but you asked. And obviously didnt understand the basics of batterirs or physics.

You dont also need me to explain that this extra battery energy and extra recharge energy comes from the alternator and directly rtelates to fuel used due to EMF do you???

Maybe you do...

Keep going this is fun.

Optima 50 amp hour battery CCA and Internal resistance figures. Compare it to any other 50 ah battery. Then maybe you will begin to get it...

Cranking Amps (SAE): 980 CA Cold Cranking Amps (SAE): 800 CCA Cold Cranking Amps (EN): 815 CCA Capacity (C/20 rate): 50 Ah Internal Resistance: 3,0mOhm

Thats better physics than Dave P!

Actually part of that is correct though... The reduced internal resistance comes from the fact that more lead surface area can be fitted into the same sized case since it doesent have to be self supporting like flat plates do. So it can be thinner and rolled up. And pure lead so that the spongy lead coating that falls off with abuse doesent need to be used to get enough surface area.

Bored now!

Au contraire, dear boy. The charging of any battery has far more to do with chemistry than physics.

This might be interesting given you need to preface it with sarcasm. Which usually means one is unsure of one's ground.

My question was about the efficiency of charging one. But get the usual spiel off your chest.

Ah - you think that? Are you using a generator with a fixed output? I think you'd find even your marvellous Optima wouldn't survive long with one of those.

Think even with your superb knowledge of physics you need to revise on the meaning of source and load impedance...

Red herring. That wasn't the question.

I was hoping for a satisfactory explanation.

If I were you I'd think about 'energy' and see how in this case the internal impedance of the battery isn't releveant. It is a product of the time and watts required for the charging process. Very little to do with the internal impedance where a regulator is involved.

It certainly seems to be taxing you.

Is that the advert over?