Prevent Pressure Build-Up in CB-Series Data Wells

Due to temperature and barometric pressure changes, or in some cases, battery off-gassing, buoys with sealed compartments, including battery and data wells, can build up pressure or establish a vacuum over time. To reduce these effects, NexSens CB-Series buoy lids are equipped with either a membrane vent or, for rough water applications, a 5 PSI pressure relief valve. The membrane vent is better at equalizing the data well with atmospheric pressure; however, the downside is that it has a higher leakage potential if submerged in rough waters. Water intrusion into the battery well can cause significant issues, including battery failure and increased off-gassing.

If a user is utilizing their electronics and data well lid, NexSens highly recommends using a pressure relief valve that is rated either equal to or less than 5 PSI. Higher PSI ranges (>5 PSI) may not be adequate to equalize with atmospheric pressure or prevent off-gassing build-up. Regular cleaning and inspection of the vent are required to avoid blockages.

Safely Opening the Battery Well

When opening the battery well, NexSens recommends the following:

  1. Do not use power tools, grinders or other equipment that could spark until the air has been removed and the compartment is in equilibrium with atmospheric pressure.
  2. Loosen all bolts manually (9/16″ socket wrench) to approximately a one-half turn to allow the pressure to equalize.
    1. Follow the pattern outlined below to apply even pressure to the lid.

Figure 1: CB-Series lid bolt removal pattern.