Which Suzuki do you have? Stock alternator replacement?
Can you verify that the problem is electrical? If so, the most common cause of electrical alternator failure is heat, usually caused by continuous high output current. Measure the voltage at the alternator AND then at the battery -- they should be almost identical. A small cheap digital voltmeter ($4 from harborfreight) will do. Measure the voltage across the battery charging wire from the alternator. It will be very, very low, but if it's more than a few millivolts, the alternator is putting out a large current. Put your hand on the alternator after it's been running a little while -- is it hot?
Stock Samurai battery is a BCI #51. It's kinda wimpy, but there's room for larger sizes.
I've crammed a #24 in there, but a #25 is a better fit, I think. Watch that the battery (+) post clears the hood. A short to the sheet metal would be catatrophic and would likely mean major carnage. Even a new battery can have a shorted cell, and that would keep the alternator running on high continuously.