Definitive Battery Thread???

pdreyfuss

Veteran Member
Joined
Mar 14, 2006
Location
Asheboro, NC
TDI
1999 Jetta
Yes, I am fully aware of that having worked as an electronics technologist in a lab environment most of my working life. We used to do real capacity tests using an Ah meter and then a more modern Torkel 860.

The question was, how many Ah are consumed during the period the glow plugs are on and I realize that varies slightly.

And the reason for asking is, members here claim the Ah rating of the battery is the most important specification. Well to make that statement, it has to be based on something other than thin air.
I think they are both important. Maybe they say ampere-hours are more important because "any" car or marine starting battery will have high CCA, but not necessarily high ampere-hours. So by specifying high A-h you get both. Just educated guesses here; I don't really know the exact numbers.
 

maxmoo

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Jan 19, 2011
Location
Lakefield, Ontario, Canada
TDI
2000 golf, 2001 golf, 2000 beetle, 2003 wagon, 2004 golf, 2004 jetta, all diesels
This backs up my reasoning for AH not being the all important factor in cold starting ability for these cars.. In the cold weather, cranking amps are what you need for easy starting.. I have a marine battery that advertizes 200AH, but my ALH will not crank fast enough with that battery to fire up in subzero conditions.. Will run the trolling motor all day though..
YUP!

From my personal experience CCA is an excellent comparative indicator of how well a battery will crank a diesel in a cold environment.

I am a firm believer in group 49 batteries with the highest cca rating that I can find for TDI's in colder climates, period.
 

tditom

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Sep 5, 2001
Location
Jackson, MI
TDI
formerly: 2001 Golf GL, '97 Passat (RIP) '98 NB, '05 B5 sedan
YUP!

From my personal experience CCA is an excellent comparative indicator of how well a battery will crank a diesel in a cold environment.

I am a firm believer in group 49 batteries with the highest cca rating that I can find for TDI's in colder climates, period.
You can't go wrong with the group 49. In addition to sufficient CCA it also provides a significant Ah advantage over the OE battery that the car was designed to operate. ;)

Essentially you can't go wrong with choosing the biggest, heaviest STARTING battery that can be secured in your vehicle.
 

993er

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Oct 10, 2013
Location
Canada
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None
You can't go wrong with the group 49.
By the way, what OEM group size is in my 2013 Jetta?

I was looking at a battery list the other day and it showed a group 48 which is also used in my Porsche. They do look about the same in size.

L = 272 mm, W = 175 mm, H = ~185 mm (difficult to measure in-car with battery blanket in place).
This would make it a group 48 battery.

A group 49 battery is a whopping 75 mm (2.9 inches) longer. There is no way it would fit (my car) and still provide the required clearance around the battery.
 
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maxmoo

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Joined
Jan 19, 2011
Location
Lakefield, Ontario, Canada
TDI
2000 golf, 2001 golf, 2000 beetle, 2003 wagon, 2004 golf, 2004 jetta, all diesels
definitive

You can't go wrong with the group 49. In addition to sufficient CCA it also provides a significant Ah advantage over the OE battery that the car was designed to operate. ;)

Essentially you can't go wrong with choosing the biggest, heaviest STARTING battery that can be secured in your vehicle.
There you have it folks.....the definitive answer to the definitive battery thread! :)
 

993er

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Oct 10, 2013
Location
Canada
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From my personal experience CCA is an excellent comparative indicator of how well a battery will crank a diesel in a cold environment.
Now I wonder where the importance of that CCA thing came from all of a sudden in this forum. ;) :D
 

tditom

Top Post Dawg
Joined
Sep 5, 2001
Location
Jackson, MI
TDI
formerly: 2001 Golf GL, '97 Passat (RIP) '98 NB, '05 B5 sedan
By the way, what OEM group size is in my 2013 Jetta?

I was looking at a battery list the other day and it showed a group 48 which is also used in my Porsche. They do look about the same in size.

L = 272 mm, W = 175 mm, H = ~185 mm (difficult to measure in-car with battery blanket in place).
This would make it a group 48 battery.

A group 49 battery is a whopping 75 mm (2.9 inches) longer. There is no way it would fit (my car) and still provide the required clearance around the battery.
I'm not sure anyone has claimed that the OE battery in the cr tdi is lacking. If that is the case with you, you could just replace it with the same unit from the dealer when the time comes. Optionally, if you can fit a 94R into the battery holder you could go that route too.

Note- there are new naming conventions in use (H6, H7, H8) that differ from the BCI (group 48, 49, 94R, etc). I always forget which is which.
 

maxmoo

Veteran Member
Joined
Jan 19, 2011
Location
Lakefield, Ontario, Canada
TDI
2000 golf, 2001 golf, 2000 beetle, 2003 wagon, 2004 golf, 2004 jetta, all diesels
By the way, what OEM group size is in my 2013 Jetta?

I was looking at a battery list the other day and it showed a group 48 which is also used in my Porsche. They do look about the same in size.

L = 272 mm, W = 175 mm, H = ~185 mm (difficult to measure in-car with battery blanket in place).
This would make it a group 48 battery.

A group 49 battery is a whopping 75 mm (2.9 inches) longer. There is no way it would fit (my car) and still provide the required clearance around the battery.
The group 49 fits in mk4 jettas and golfs.
Other models may not be able to fit a group 49, however most vw's do have the room to move up one or two sizes from what they originally came with. Do your own research and measuring.
 

Gruni14

Well-known member
Joined
Dec 23, 2007
Location
Madison
TDI
2002 Jetta
I've been running an Optima yellow top D75/25 (620CCA) for years. No problems. And we get lots of -20* and colder temps in the winter here. Car sits outside 100% of time. Never had a single iota of a problem starting.
http://www.atbatt.com/optima-d75-25-yellowtop-battery-8042-218-bci-group-size-75-25.asp

As for fitment, the poles are opposite of the OEM battery but the Optima is smaller. The + is tight like a fiddle string because the poles on this battery are at the edges. The only issue is the top thing-a-ma-jig snaps down on one side, but not quite on the driver's side. But the cover fits on. I believe it is like 1/4" from the seat where it should be and doesn't snap in place, but overall works. It's probably been in there 5 years now.

Optima has other batteries like the D35 or D34 that have slightly different pole arrangements that would probably work better. A red top would be cheaper, but at the time when my vehicle died I had an Optima Yellow-top sitting on the shop floor (on a board of course) and asked my wife to grab it and bring it down. So that's what I used. Napa quoted me like $300 for a German made, VW-fit battery at the time so there wasn't any reason to pull the Optima out. I like the top/side terminal arrangement of the D75/25 as a good 'universal' battery for some of my GM vehicles and non-GM vehicles. I have several Yellow-tops. Never had a problem with them.
 
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tditom

Top Post Dawg
Joined
Sep 5, 2001
Location
Jackson, MI
TDI
formerly: 2001 Golf GL, '97 Passat (RIP) '98 NB, '05 B5 sedan
I've been running an Optima yellow top D75/25 (620CCA) for years. No problems. And we get lots of -20* and colder temps in the winter here. Car sits outside 100% of time. Never had a single iota of a problem starting.
http://www.atbatt.com/optima-d75-25-yellowtop-battery-8042-218-bci-group-size-75-25.asp

As for fitment, the poles are opposite of the OEM battery but the Optima is smaller. The + is tight like a fiddle string because the poles on this battery are at the edges. The only issue is the top thing-a-ma-jig snaps down on one side, but not quite on the driver's side. But the cover fits on. I believe it is like 1/4" from the seat where it should be and doesn't snap in place, but overall works. It's probably been in there 5 years now.

Optima has other batteries like the D35 or D34 that have slightly different pole arrangements that would probably work better. A red top would be cheaper, but at the time when my vehicle died I had an Optima Yellow-top sitting on the shop floor (on a board of course) and asked my wife to grab it and bring it down. So that's what I used. Napa quoted me like $300 for a German made, VW-fit battery at the time so there wasn't any reason to pull the Optima out. I like the top/side terminal arrangement of the D75/25 as a good 'universal' battery for some of my GM vehicles and non-GM vehicles. I have several Yellow-tops. Never had a problem with them.
I think you've been lucky so far to not have an issue. It's very important to secure the battery and to give adequate service loop to the cable. If it is under tension as you say then its only a matter of time before something breaks. And that never seems to happen at a convenient time...
 

cheoah

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Oct 6, 2013
Location
Western NC
TDI
'06 Jetta PD, '14 Passat
Deep cycle batteries like marine batteries are different, with much thicker plates. They are not capable of delivering the kind of amperage that a starting battery can. Dual purpose batts are popular in marine stores. The diesel on my sailboat once used a marine type battery but I replaced it with an automotive type. The thin plates also take a charge quickly. I put a NAPA in my 06, not sure what grp it is.




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