I'm using an AGM battery from Batteries Plus. Mind the wrap...Those look like the Dekas, rebadged. Mine was a "Big Crank", which is also a rebadged Deka.
http://www.batteriesplus.com/products/558-CC/4518-Motorcycle-Batteries/136419-Kawasaki/ZG1000--A-Concours/1000CC-1986-to-2006/1.aspx
Damn Doug, 6 years on the stock battery. You must be doing something right. I had the stocker in my old Valkyrie for 7 years. Replaced it before i sold it to the new owner. let us know what you decide on.I did everything wrong and my stock (2006) battery is still in useable condition. I replaced it last year (5 seasons of use) because I abused it so badly. (Rarely checked water level, twice found it with about 1/2" of water left in all the cells - yet still started the bike just fine) But I put it in use for my electric start generator. Works fine there, and I can easily check the water level.
My Deka died after 13 months. (12 month warranty. ) Within a half hour of charging, it reads 11.5V. Not so happy with them at the moment. But the place I bought it from has offered to let me return it, and they'll test it and set it aside for the Deka rep to see if they'll honor the warranty anyway.Gotta give an update and a HUGE "Thank You" to the folks at batterymart.com They just informed me that they are going to honor the warranty and will be sending my new battery shortly. I'm only out $10.85 that it cost me to ship in a USPS Flat Rate box. (Got my money's worth out of that postage!)
So, now I'm using a battery pulled out of a Harbor Freight jump starter. Works well, and the claim on the jump starter is 400A, which surpasses the 310A of the Deka. Only change to the bike is longer screws in the front of the tool tray. (Which I haven't even done yet. ) For $40 for a sealed battery, it seems like a good deal.
I had another Deka in a Honda CB750F that I was quite happy with. Guess I just got a bad one this time around.
I'm running a Motobatt AGM that Murph used to sell. Been on it for 2 years now. No complaints.