The car is 1985. Spiral Cell AGM Battery needs charging. Need Special process?

This info is correct found on Mazda Miata web site: One of the differences with the AGM battery compared to the wet-cell battery is the recharge rate. That is, how fast you can put energy back into the battery. With a wet-cell battery you can "quick charge" it at about 20 amps or more. Usually this is when you would boil the electrolyte right out of the battery. The AGM batteries require a lower charge rate, for a longer time period. If your battery will not crank the engine, you should charge the battery at a rate of 1 amp or less for 18-24 hours. If you try and charge it like a wet-cell battery, you will destroy the battery.