IF........you could be assured that the battery you were purchasing from the dealer had been made to the same specs as the ORIGINAL battery (that came from factory) in the tractor, then yes.............it MIGHT be worth the extra cost.
If you do the math based on cost of batteries factoring a hypothetical 7 year life span, your investment in the OEM battery would probably be much less. Especially if you consider your time and troubles involved in procuring the cheepo batteries.
But, I don't think it is safe to bet that buying an OEM battery will guarantee "a 7 year life span" for each and every situation.
There are many variables that can affect the longevity of any battery, regardless of where it was bought.
It is safe to say that most reputable OEMs will select a battery for the assembly line based on factors that retail mass marketeers are not really concerned about, such as leakage around posts, etc.
Just one "unknown factor" in this equation is the fact that during the 7 to 8 years since your present battery was placed into service by Deere, Deere might not be acquiring batteries for their replacement parts network from the same source that they used when building that production run "back when".
And even if they are........who can say if the present batteries are "as good" as the ones 7-8 years ago?

This post was edited by mownie on Tue, Feb 26, 13 at 12:23

I have used the cheap batteries for a long time, and get 2.5 to 3.5 years for each on a 350 amp/hour battery and spend less than $30 ea.

If you buy an OEM battery you will spend about twice that or $60 ea. OR it is a wash as far as cost per year.

I think it depends on how you treat the battery when we lived in Indiana the battery was always brought into the warmth of the garage, instead of leaving it on the tractor in the freezing shed.

When it comes to choosing an OEM battery supplier and the quality level of the battery an important consideration is the delivered price per unit to the location of the assembly facility. Batteries are expensive to ship, even in quantity, so the freight cost and distance from battery supplier to production line is important to the cost analysis people at the factory.

Another factor in OEM battery service life is that an OEM battery is installed in a brand new vehicle with brand new wiring and brand new connectors. This all contributes to longer battery service life.

My experience has also been that OEM batteries have a longer service life than replacement batteries if one buys replacements without really researching what one is getting for their money.

Between the major battery manufacturers in the US who are ESB (Exide), Johnson Controls, and DEKA (East Penn) the highest quality battery I've found are those manufactured by DEKA (East Penn). The DEKA made in USA batteries are commonly OEM and are sold as replacement batteries on the east side of the Mississippi. Some companies manufacture in Mexico like Johnson controls.

If you can find a DEKA (East Penn) LT/GT battery with the correct CCA for your application they are worth the trouble to find.

WalMart EverStart and Sears Die HARD and AutoZone LT/GT batteries have the shortest service life.

I have equaled the 6-7 year OEM battery life in two of my LT/GTs (Scotts and Toro) by hunting down DEKA (East Penn) replacement batteries with the same CCA and have never used battery tenders or the like. My current GT (JD X500) will get a DEKA battery when the time comes.

This post was edited by justalurker on Tue, Feb 26, 13 at 14:32

Are the replacement battery frames cracked?

I had the same experience with my Simplicity, got 5 years on the original battery and have replaced it every two years. This winter I hooked up a trickle charger not sure if that will extend the life or not.

One thing in real cold climates is that if you let your battery discharge it can freeze and break the plates.

That is why you should bring the battery into a warm area and keep it charged through the winter.

It will extend the battery's life

Gotta be a cracked battery frame - it's always been wheely's solution for everything else...

Batteries are based on CCA's, the more CCA's the more plates, the more plates more weight, more weight (lead) the more they cost. Cheap batteries has less weight, less weight less plates, less plates cheaper price. SO, IMO the more CCA's the longer the battery should last cause it don't take 350 CA's to turn small gas engine only about 100 give or take. Buy cheap get less, buy by weight (CCA's) get more...... I buy cheap cause I'm cheap and use all the ideas to make it last (usually about 3 to 5 years.

Well as you can see the tractor is garaged and is used regularly; a little more regularly this winter then last.

Thanks for the info justalurker.