[nickyt]

In practice, my last several AGM batteries are lasting shorter, not longer.

My last AGM developed a tumor (swelled case) around a single point. That of course indicates that one single cell short circuited and during that process, it got hot enough to cause damage to the plastic case the AGM was installed in.

Since it was inside a 100% sealed case, I consider that a manufacturer fault. Alas, it was just a few months past any warranty. I would have liked to got my $3.60 credit for being in the last 3 months of a pro-rated battery warranty claim.

You didn't do anything wrong with an AGM (I have used several) but I doubt that you gained any additional lifespan.

A CTEK battery charger is imo the best and what I normally use. They are AGM rated.

FWIW, last year I retired an 11 year old flooded cell battery. That was one heck of a good battery. I replaced it with another flooded cell. They are just lasting longer.

 

[Gadgetman]

I'm looking to buy a kirkland battery as mine is slowly dying. Do we need AGM battery or a old lead liquid battery will do the trick. I'm asking because the battery is right under my seat and I dont want sulfuric acid in my a** if something wrong happens to the battery.
There is no BEM code on it and I dont have the 61 module in my car ( 2013 tdi execline). SO will I have to code something ? ( if yes, what can I code since there is not BEM sticker on it )
thank you

I think you can replace it with anything that has similar performance, but make sure it is a sealed type (no removable cell caps) with a vent at the end, there is a small vent tube from the battery box to the outside that needs to be reconnected to the new battery. For coding find a similar battery in the coding list and use that, but may not be a big deal as long as the serial# and capacity are coded. The changed serial forces the computer to recognize it as a new battery. The manufacturer code is supposed to optimize the charging for that battery according to the manufacturer.

For others good luck relocating the battery, it is a PITA to change but in reality is in a great location, when I removed my old battery you would have thought it was still brand new, it was so clean without any corrosion.

 

[BenTDI]

For a 2015 TDI, is the H9/95R-the correct size for a direct replacement?

 

[Gadgetman]

I have no idea, what I did was checked what was installed and purchased a similar battery, I have the V8 TDI so it's the largest that will fit, yours maybe smaller, and you could go larger if you wanted. I installed a Bosch ST Hightec AGM LN6 which is actually manufactured by Varta.