Abstract: A wet cell battery electrolyte level monitor monitors the electrolyte fluid level of individual battery cells on battery powered mobile or stationary equipment. The one piece monitor includes a probe housing with associated circuitry and two wire leads. The monitor wire leads may be permanently or temporarily attached to the battery system voltage and battery system ground. After removing the battery fill cap of a specific cell, the probe is inserted into the fill cap opening on the battery. The monitor's electrolyte level indicator provides an indication that the electrolyte is at the battery manufacturer's recommended level. If the indicator does not illuminate, water needs to be added to the batteries.