Question: If calcium grids don't do well in flooded deep cycle applications... How can Dynacell use calcium grids in gel cells for deep cycle? Answer: Flooded calcium is a very efficient, low resistance battery. Therefore, when deeply discharge, the plates give up all of their available power... which eventually causes plate shedding and active material fall-out. Flooded antimony. The antimony in the grid helps lock the active material onto the grid. Therefore the plate does not shed as easily, which extends the cycle life of the battery when compared to flooded calcium. Gelled calcium (EPM's exclusive patented alloy) is very efficient with low resistance. However, when deeply discharged, because the battery is acid limited, the electrolyte is used up before the plates are totally discharged... which limits the discharge the plates can deliver, which protects the plates from shedding, which extends the life of the battery.