Veebyes wrote:
A wet cell will typically only lose 10% of charge a month. Leaving it on a trickle charge runs the risk of charger malfunction & boiling off the acid. One trashed battery for no good reason.
That is why you use a float charger (Batterytender or work-a-like). Sulfation will start to occur when a battery’s charge state falls below 80 percent. The sulfate material attaches to the discharged portions of the battery's plates and begins to harden into crystals. The sulfate cannot be converted back into active plate material and slowly the battery's capacity is reduced and eventually the battery is destroyed.