NOTE: Please keep in mind that these techniques work for the Perdix, Petrel, Petrel 2, and Predator despite the slightly different design of each computer.

O-ring Specification:

Petrel: #112, 70D, Buna-N (Nitrile, NBR)

Service Requirements:

  • For Each Battery change:  Clean, check for signs of damage, and lubricate without removing O-ring
  • Replace if damage detected: Remove, replace, lubricate and install new O-ring if signs of wear, compression set, cracking, corrosion or degradation

Removal procedure:

Note: Please contact dive shop if apprehensive with removing O-ring

1. Pierce O-ring with a pointed instrument (i.e. O-ring pick, Safety pin, Push pin)


Removal Step 1



Removal Step 2




WarningRISK OF FLOODING if inner surface of gland is scratched or damaged while piercing O-ring

2. Puncture surface and lift O-ring out of groove and over battery cap

Removal Step 4

Installation procedure:


1. Lubricate O-ring with a thin film before installing

Benefits of lubricating O-ring:

  • Protects the O-ring from damage by abrasion, pinching, or cutting.
  • Helps to seat the O-ring properly
  • Protection as a surface film
  • Protects from degradation by atmospheric elements such as ozone
  • Extends the service life

 Do not use lubricants with the same base materials
(i.e. Do not use Silicone grease with Silicone O-rings)


Installation Step 2
Install Final

2. Stretch O-ring over battery cap from the end without the spring and threads until O-ring is seated in groove


Ensure all component parts are clean at time of assembly. Foreign particles (i.e. dust, dirt, sand, grit, etc.) in the gland may cause leakage and can damage the O-ring and groove, reducing its life.

WarningRISK OF FLOODING from damage or twisting if forced over threads during installation

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