NOTICE : STILL BEING EDITED
NO # 2 : MODERATE TEMPERATURE FOR MAXIMUM PERFORMANCE
It's common knowledge that extreme temperatures reduces the lifespan of lead acid batteries, I won't go into details about chemical reactions etc but I will state what I had done under existing circumstances (battery in the engine bay) being in a tropical country.
Cars that have their battery located in places other than the engine bay, the battery seems to be able to hold out longer than those in the engine Bay Area. Besides my father-in-law very old Toyota Corona with exceptionally large bonnet allows maximum Ventilation within a confined space as compared to modern smaller cars.
NOTE : I believe the key word is PROLONGED EXPOSURE TO EXTREME TEMPERATURES which actually reduces its lifespan.
A) INSULATE THE BATTERY - Having an insulator in place helps cut the heat being radiated to the battery drastically.
B) OPEN UP THE BONNET FOR MAXIMUM AERATION & HEAT DISSIPATION - After most of my drives where permissible, I will open up my bonnet even to the Service Center for the engine bay to cool faster.