This extension battery is an additional item to extend longer running times on the Solar SDS Generators. Operates via the Solar SDS cigarette socket. Added to this you can connect additional extension batteries (daisy chain) by connecting through the separate parallel female cigarette socket. The Solar SDS 12V 33 Ah Extension Battery, is a valve regulated lead acid battery with absorbed glass matt separators. Simply connect the cigarette housing into the Solar SDS for longer running time. It can be used to power other applications, & is maintenance free. Transport by air, sea & road This type of battery has the same cyclic advantages commonly associated with GEL types, but also provides greater capacity per unit size, therefore handles larger load duration. The base technology is absorbed glass matt, as the battery electrolyte is fully absorbed within the internal separators within the battery, this means there is no possibility of electrolyte spillage even if broken. In turn these batteries are classified non-hazardous, & not subject to any transport restrictions.