use Agm as starter battery in nissan pulsar??

If AGM batteries are factory fitted in the Rolls-Royce Phantom, Bentley Continental GT, Porsche Cayenne, Mercedes Benz SL and Audi A8...

Why not in a Nissan Pulsar?

The OP already gave the reason for his/her intention: you can pretty much discharge a spiral wound pure lead/tin AGM battery down to almost zilch SOC and still crank your car.

BTW, the saving over a stock standard flooded type battery isn't a couple of hundred Dollars. It's more like 60 or 70 bucks - peanuts really if you take into account the better life span and deep cyclability.

Peter

Peter,
What reason would you give for needing a cranking battery of 690 CCA's in a small 4 cylinder Nissan Pulser, a battery that will very easily start a large Diesel in a 4wd.

The battery in question is a Hungarian made Deep Cycle battery, however a spiral wound battery of lesser CCA's which is more suitable to a Pulsar, can be obtained for under $190, and I think that's a waste of money too compared to what is available, for instance I use a $99 battery in my 4 cylinder diesel without hassles and it will easily start a 6 cylinder Holden or Falcon.

Maîneÿ . . .

If you select a smaller spiral wound battery, you lose Ah.
And Ah is, what the OP wants the AGM for.
The high cranking and cold cranking amps is only a (positive) side effect.
It's that simple.

Peter

Peter,
are we both reading the same thread?

he states:
" wants to use Agm as *starter* battery in nissan pulsar

I am soon to replace my *starter* battery in my nissan pulsar.
Is it a good idea to replace with an agm ?
Would I expect agm to be more reliable and offer a longer life ?
Advice is welcomed.
Its main use would be as a *starter* battery but I thought as an agm would be more tollerent to lights being left on etc "

Maîneÿ . . .

The Ah are for this:
...but I thought as an agm would be more tollerent to lights being left on etc...

And if the OP wouldn't want 'this', then he/she is better advised using an ordinary cranking battery with no deep cycle capability.

Now my friend, that's all there is to it - I'm not going to enter one of you silly merry go rounds again.

Peter

If he leaves the lights on and flattens the battery it is flat, even if it is an AGM battery it is still flat and it won't start the vehicle.

I remember all the threads on EO claiming an Alternator will only charge a battery 80% - therefore it will never be fully charged *under those conditions* and will fail, as sure as night follows day.

Then there is of course the charging Voltage required to charge the Deep Cycle battery ??
Will the Pulsar Alternator be capable of fully charging the Deep Cycle battery ??
The small Blue top Optima specifications are Alternator charging @ 13.65 to 15.0 volts

So many questions left unanswered

Maîneÿ . . .

I have limited battery knowledge, but talking to a battery salesman today he told me that an AGM battery requires significantly less time to be charged by the alternator than a wet cell battery, and that the particular AGM I was looking at only needed a max of 14.6ish volts to charge it.

Cheers

TTTSA

Hello TTSA,

AGMs charge faster than flooded type batteries, that's correct.
F.e. spiral wound pure lead/tin AGM batteries can be recharged to over 90% of full charge, within 45 minutes.

And if the battery gets deeply discharged (and that's true for both AGM and flooded), then both types need a higher voltage just before the end of the charging process, to keep all six cells nicely balanced electrochemically.
For flooded batteries, this is called equalisation voltage and it's quite high - around 15.5V.

Due to lower cell polarisation in AGM batteries (caused by the O/H2 recombination near the negative plate surface), the terminal voltage requirement for cell equalisation is also lower.
And the terminology is also different: it's called boost voltage, instead of equalisation voltage.

Fact is, that AGM batteries are more prone to developing cell imbalances, because they're frequently used in deep cycle applications. And this is why they routinely (should) get charged at the higher boost voltage setting.
Flooded type 12V batteries are not designed for regular deep discharging.
F.e. a starter batteries may get to see only a few percent of depth of discharge before recharging takes place.
That's why you don't have to apply an equalisation charging voltage on these. 13.8V float charging keeps them happy.
Different story with flooded deep cycle 2V cells for cyclic energy storage apps like solar: these need to be equalisation charged every now and then to pull all cells in the 12V/24V/48V series string, in line.

To sum it up:
if you expect a long life from any battery which is subject to regular deep discharges, it's important to occasionally apply the higher voltage required for cell equalisation.
If you decide not to follow this advice, the six cells inside the battery will develop different Ah capacities, and it's a runaway effect.

That's precisely the reason why some seasoned 'battery users' insist that all you can expect from a deep cycle battery is a couple of hundred cycles, while if treated properly, the achievable cycle life can be five times higher.

Hope this clears things up for you.

Best regards, Peter

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Hello TerraFirma,

interesting that you mention the ride on mower.
On my old ride on, I think it's got a 12.5HP B&S engine - the charging circuit makes my AGM starter battery go up to 17V...
At this voltage, there's a lot of gassing going on, so I permanently disconnected the charging wire from the battery. When done mowing, I put the battery on a mains powered charger.

I guess your mower's charging system has a better regulated voltage output?
By any chance, have you measured it at some stage?

Would be interesting to know, thanks.

cheers, Peter

I believe Lithium versions (eg LiFePO4) are the future in batteries but who cares LOL

Thanks for taking the time to respond with a thanks to those that were helpful. Good luck with your purchase :)

Andrew