What is a Flooded battery?

A Flooded battery is a lead-acid electric storage battery with excess electrolytes (water and sulfuric acid) flooding the individual cells of the battery. The fluid levels must be maintained above the plates and connectors for a flooded battery to avoid premature failure.

Flooded or wet batteries:

  • It can have either sealed manifold venting or accessible venting designs.
  • Can use High Antimony, Low Antimony or Calcium Lead metal grid alloys or a combination of Calcium and Low Antimony grids (hybrid).
  • Uses various grid thicknesses relative to application needs and cost requirements.
  • Thin grid + low active material ratios & low material density - used in general-purpose starting applications. More plates mean more cold-cranking performance.
  • Thicker grids + higher active material ratios with increasing material densities - used in purpose-built Enhanced Flooded Batteries (EFB) for Micro-cyclic start-stop vehicles and other emerging specialty transportation requirements. Also, in general-purpose Marine/RV high cycle applications.
  • Thick grid + high active material ratios & high material density - used in purpose-built Semi-Traction Industrial and commercial Deep Cycle and Long-Life Renewable Energy use.
  • Requires rigorous levels of maintenance depending upon use.
  • Its entire electrolyte volume is free to move within the cell with nothing to prevent the escape of hydrogen and oxygen gases usually lost during charging and discharging (particularly in Deep Cycle applications).
  • Are considered Flooded because it has an excess of electrolytes, which allows the plates to be completely and even over-discharged while delivering the batteries usable power.
  • Escaping gasses in the discharge/charge cycle can be detrimental to users, sensitive electronic equipment and the environment due to its corrosive nature.
  • They are spillable and, therefore, can only be operated in an upright position. This includes sealed maintenance-free versions of the flooded battery type.
  • Are classified as Hazardous.
  • Flooded batteries need equalization charging as a countermeasure against acid stratification, which is the #1 killer of lead-acid batteries.