Thread: D2a TD5 Auto Cranking Battery

Originally Posted by sharmy

AGMs are not designed to be used as starting batteries and while many do, they really should not be placed under the bonnet. They do not like too much heat and can swell up.

They are just plain starting flatteries as far as I can tell, can't see AGM anywhere.

Originally Posted by sierrafery

You need a minimum 110AH battery, the high CCA is not enough on it's own

I disagree coz I want to disagree even if you're correct ( I'm like that), it is a starting battery and has a good RC too, anyway what is a 'minimum' of 110AH mean to a mug like me, if it starts the car it is a good flattery as the alternator runs the car after that.

Only time I have ever had issues (in a different car) is aircon working with thermatics continually on in stop start traffic with a dud low output alternator, the battery was draining at the traffic lights and the driving in between wasn't enough to top it up. Ended up a very hot drive with aircon off.

A well tuned and behaving car doesn't need as much current to turn over as people believe.

But in my opinion always having a starting battery with overkill cca specs above manufacturer requirements and a good top up and float charge every so often leads to a very happy long lived unit.

Originally Posted by sharmy

AGMs are not designed to be used as starting batteries and while many do, they really should not be placed under the bonnet. They do not like too much heat and can swell up.

Not true in any way shape or form.

You keep making these comments and they are totally incorrect.

There are specific “house” AGMs which aren’t fit for this purpose, then there are versions designed for exactly use under bonnet, cranking and stop/start.

Wet cells evap/boil off under bonnet also. Location of battery, airflow and operating environment all play a part.

I think the argument re high AH is more about the well known parasitic draw from the D2 system.

I have a smaller wet battery (750CCA) next to my turbo as a starting battery and it does go down to about 12.5 after only a few days. The biggest I could fit in the ARB cradle.

I had a Yellow top there but the cell nearest the turbo seemed to lose power as it would only charge to say 12.7 so I replaced it with a high quality( long warranty) Exide Extreme XDIN66HDMF.
So far about 2 years no problem.

I recommend the biggest physical and CCA wet battery that you can fit in the stock cradle which takes a 330MM long battery. The Exide Extremes seem quite good.

I have a pulse generator also on mine so that should reduce sulphation , and the Exide Extreme has anti sulphation additives.
I have an AGM in my stock cradle as house battery which is 130AH and seems to be good as it usually holds over 13 volts.
Regards PhilipA

Originally Posted by sierrafery

Maybe the D2 charges AGM "fine" but not well IMHO... AFAIK AGM batteries need higher(around 14,8) and more constant voltage for charge than the D2's alternator was designed for cos it was conceived for lead acid battery..................

AGM's are SLA's (Sealed Lead Acid) I know as I went to Battery University, no really, BU-201a: Absorbent Glass Mat (AGM) - Battery University

Originally Posted by Tombie

Not true in any way shape or form.

You keep making these comments and they are totally incorrect.

There are specific “house” AGMs which aren’t fit for this purpose, then there are versions designed for exactly use under bonnet, cranking and stop/start.

Wet cells evap/boil off under bonnet also. Location of battery, airflow and operating environment all play a part.

Ok, list all my totally incorrect comments and tell me which AGMs have "house" emblazed on them. I stuck an AGM under the bonnet to start my car so I could take it to my local battery dealer to replace a starter one that had failed failed. That's when I was told they should not be placed under the bonnet. Then there was a tv news report, when the fire brigade was called to a caravan park to hose down a super swollen AGM battery,
Cheers to you

Originally Posted by sharmy

.... Then there was a tv news report, when the fire brigade was called to a caravan park to hose down a super swollen AGM battery,
Cheers to you

It was more likely over charged, than heat affected.

I have had 2 AGMs next to my turbo and no swelling.
The stock cradle is in a cooler place than many other cars eg Toyotas so IMHO AGMs are OK there.
Some AGMs with only an AH rating should only be house batteries. Dual purpose ones will have AH and CCA on them.
Regards PhilipA