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2007 VW EOS 3.2 V6 DSG
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Discussion Starter · #1 ·
Does anyone have any views/experience of using Optima 6V Red Top batteries in the VW V6 Eos (two 6V batteries connected in series)? The original Optima 6V Yellow Top batteries do not seem to be available (I suspect they were a VW Eos special production item) and I know some people use the Red Top batteries as a replacement.

From the full service records I have for my car it looks like the original Yellow Top batteries lasted 12 years. The replacement Red Top batteries are just three years old and are showing signs of impending failure.

I understand that Optima Yellow Top batteries are deep cycle AGM batteries intended for high power drain cars like an Eos when the roof is being put up and down. Red Top batteries are not designed to handle this high power drain - hence I was expecting a shorter life - but three years is not enough.

According to Optima "Key benefits of OPTIMA YELLOWTOP® batteries include deep-cycling battery and OPTIMAL starting power ..". But "Key benefits of REDTOP® Batteries include the strongest starting burst" which clearing does not include the deep-cycling capability.

I am reluctant to install another set of two 6V Optima Red Top batteries - I am thinking of purchasing a high end suitable AGM deep cycling 12V battery and making some changes in my boot (the batteries main wire leads, the battery trays and the battery covers) to accomodate a single better battery with a long prospective life.

Has anyone gone down this path when they needed a new battery(ies) in their VW Eos V6?

Cheers

Catweazle
 

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2008 Volkswagen VR6 Eos
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The yellow tops are still available from many suppliers.


The concept behind using deep cycle batteries was so that the top could be open/closed many times without the car running. If you have the car running when you operate the top, you negate the need for deep cycle batteries. Although I have no direct experience with the red top Optimas, most all that have used them in their VR6 have reported no issues.

A battery lasting 12 years is an anomaly and not typical of any battery

The 4 cyl EOS uses a non deep cycle AGM battery, its a 61 AH, 330 CCA battery.
 

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2007 VW EOS 3.2 V6 DSG
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Discussion Starter · #3 ·
The yellow tops are still available from many suppliers.


The concept behind using deep cycle batteries was so that the top could be open/closed many times without the car running. If you have the car running when you operate the top, you negate the need for deep cycle batteries. Although I have no direct experience with the red top Optimas, most all that have used them in their VR6 have reported no issues.

A battery lasting 12 years is an anomaly and not typical of any battery

The 4 cyl EOS uses a non deep cycle AGM battery, its a 61 AH, 330 CCA battery.
Yes - seems to be in the UK. But not in New Zealand and google does not suggest these batteries are available in other markets.

Cheers

Catweazle
 

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I understand that Optima Yellow Top batteries are deep cycle AGM batteries intended for high power drain cars like an Eos when the roof is being put up and down.
You shouldn't do that, always run the engine so the alternator is charging.

The biggest load on a car battery is the starter cranking current (high for a V6?) and that's one of the specs on most battery types (CCA). Battery life is significantly shorter when you leave the car standing for long periods and start with a low charge battery. 24/7 trickle tender is the answer if you park near a mains point. Some cars have high battery drain problems which can leave a battery very low in charge when left even for a week. Best to get ignition key off drain checked before condemning the batteries.

My suspicion is it will be the high V6 starting CCA that will reduce your battery life: Looking at the specs, a yellow top AGM is 55Ah capacity with a 450 CCA. A red top AGM is 720 CCA but their CCA specs seem to vary with the actual part number used? IMHO you need at least 680 - 750 CCA for the diesel and V6 - higher is best. Sufficient CCA and maintaining a full charge should give best battery life. The V6 will have the higher long cable loss which will increase the CCA demand when cranking.

The EOS might be regarded as a high current consumer, that will mostly apply when the engine isn't running. Even the roof pump load should be balanced out at idle. But it's the high current shock loads that are important.

 

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2008 Volkswagen VR6 Eos
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You shouldn't do that, always run the engine so the alternator is charging.

The biggest load on a car battery is the starter cranking current (high for a V6?) and that's one of the specs on most battery types (CCA). Battery life is significantly shorter when you leave the car standing for long periods and start with a low charge battery. 24/7 trickle tender is the answer if you park near a mains point. Some cars have high battery drain problems which can leave a battery very low in charge when left even for a week. Best to get ignition key off drain checked before condemning the batteries.

My suspicion is it will be the high V6 starting CCA that will reduce your battery life: Looking at the specs, a yellow top AGM is 55Ah capacity with a 450 CCA. A red top AGM is 720 CCA but their CCA specs seem to vary with the actual part number used? IMHO you need at least 680 - 750 CCA for the diesel and V6 - higher is best. Sufficient CCA and maintaining a full charge should give best battery life. The V6 will have the higher long cable loss which will increase the CCA demand when cranking.

The EOS might be regarded as a high current consumer, that will mostly apply when the engine isn't running. Even the roof pump load should be balanced out at idle. But it's the high current shock loads that are important.

FWIW, the factory yellow top optima batteries are 750 CCA not 450 CCA. The red top Optima is listed as 800 CCA and 50 AH. While there are several different varieties of 6 volt red tops, there is only one that has the exact dimensions as the yellow top.

 

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but their CCA specs seem to vary with the actual part number used?
Just goes to show the color of the top doesn't define the spec:
The one I looked at was 12V @ 450 CCA with yellow tops. Thanks for the clarification.
 
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