... , hot-dip galvanized, plastic spray coating,C, Life span, no rusting within 30 years.Solar panel: A, Solar panel, amorphous ... panel's Characteristic, conversion efficiency is high(15—19%),the size is small and the life time is long.C, Life span ... casing, insulation & waterproof of the electrodes are well considered, therefore no electricity leakage & water seepage when the battery is buried underground ...