Exide INVA GOLD is manufactured as per Exides proprietary Premium Akkumulatoren using one of the worlds most exclusive, advanced and state-of-the-art HADI high pressure spine casting machines, which is not commonly available. With hi-tech R&D center at Kolkata, Exide Inva Gold has developed the high-corrosion resistant and robust spine technology using the HADI process, which ensures a super fine grain structure, for strength, long life and highest reliability.This battery most sucessful for Solar system and compare to other models like Exide Solar blitz and Exide EL series .