Battery Cable problems of the 1996 Chevrolet Tahoe

I have a 96 chevy Tahoe. It has 37,000 miles and is, therefore, just outside the 36,000 mile bumper to bumper warranty. I have talked to several other chevy truck owners and they tell me that chevy trucks have a problem with batteries. Though the battery is rated at 72 months, it only lasts for approximately 24 months. I have asked two different mechanics at the chevy dealer (macpherson Chevrolet) and they say that it is true - batteries only last about 2 years. They also admit that they replace hundreds of batteries, often repeatedly on the same vehicles. They also tell me that in their opinion it is a gm design defect that the manufacturer has chosen to ignore. I have now replaced the battery twice (this is the third battery in the vehicle). The first time gm paid for it under the warranty. The second time it was just out of warranty so I had to pay for it. I also had to pay for repair of a battery cable that leaking battery fluid had damaged. Though the dealer admits that the 72 month warranty is printed right on the battery, they say that the warranty ends with all other warrantees at 36,000 miles. That is gm policy and they showed me a memo from gm saying so. I had planned to keep this vehicle for a couple of years. However I do not relish the thought of having a very unreliable vehicle when I travel for any distance, knowing that the battery may go dead at any time. By the way, when this happens, due to the all electronic nature of the engine, nothing works - the engine dies, the power brakes no longer work, and the power steering no longer works, even at freeway speed. In my opinion this is very dangerous behavior. Thanks for your assistance, tom nickelsen.