The winter of 2012/2013 finally took its toll on the battery in my 1991 Mercedes-Benz 420 SEL. It was starting to show signs of failure upon cranking, so it was time to replace it before it left me stranded. For the replacement, I chose the Deka Intimidator Absorbed Glass Matt (AGM) battery. Sometimes, these batteries are referred to as Valve Regulated Lead Acid (VRLA) batteries. The BCI group size for this battery is 49. The Enersys Odyssey battery recently installed in my 1995 Ford F-250 is another example of AGM/VRLA technology.
The primary reason I chose the Deka over the Odyssey mainly has to do with fitment. I couldn't find an Odyssey battery that exactly matched the BCI group 49 size at the time I was researching a replacement. While the Odyssey edges out the Deka by sporting nearly 100% pure lead plates and tin coated brass terminals, both batteries are of exceptional quality and should last a very long time. The same benefits the Odyssey battery sports also apply to the Deka Intimidator. I also have a Deka AGM battery in my 1970 Mercedes-Benz 280 SEL and I've had very good luck with it.
Try to pay attention when you start your car and let the car "talk to you." In most cases, you can be alerted to issues, including the battery, that you can proactively address before they cause allot of inconvenience and perhaps money. (3/24/2013)