Ultra Max NPG18-12 AGM/GEL Battery 12V 18AH (Replace 12V 17AH, 12V 19AH, 12V 20AH, 12V 21AH, 12V 22AH). (12V 18Ah). GEL BATTERY. SUPERIOR SHELF LIFE WHEN COMPARED TO WET CELL BATTERIES. Weight / battery 6Kg.
eBay