Hydro-Eye LLC was formed in 1999 and a US patent (# 6040079) was issued in March 2000. Flow-Rite Controls asked for a probe that would fit their standard inspection port and has been a steady customer since early 1999. Since starting, Hydro-Eye has sold over 65,000 probes, all of the monitor type using a single green LED as an indicator of an acceptable water level in a flooded lead-acid battery.

In 2005, in our ninth year of operation, we have decided to expand our product line to include active probes rather than just those with a passive LED. The primary objective is to alert the user as to a low water level rather than just displaying an extinguished green LED. The result is a whole family of probes. We have the basic Monitor types, as before, plus Alarm probes that flash either a bright red or a blue LED when the water is low, or Combo units, with both the green Monitor LED as well as the flashing Alarm LED. These two new types will fit in the basic quarter-turn vent cap, but the 5/8" diameter cap used in the original EEP-2 design is too small and had to be increased to 7/8" diameter instead.

We have expanded our product line to include the Push-In cap used on 8D batteries and cell covers with built-in probes for Group 24 and Group 27 batteries for those not wanting to install the probe itself (even though it's easy).

Hydro-Eye is also working with Watermaster of America on a probe for their exciting new golf cart battery watering system.