DGF Series batteries are flooded tubular battery, rechargeable lead-acid batteries which in contrast to conventional systems, retain positive plates as tubular structure. Reliable pillar sealing construction, absolute no pillar corrosion. Against short circuit design with the highest possibility to prevent any short circuit. Flexible option for automatic refilling system and air circulation system. Nonwoven protective gauntlet, better elastic, less pore size, less electrical resistance and higher air permeability.