BLOG
Waterproof Robot Power Supply Design: How to Meet IP68 Standards for Autonomous Marine Robots
Table of contents
Why IP68 Power Supplies Are Essential for Marine Robotics
Autonomous marine robots—including underwater drones, inspection ROVs, surface boats, and environmental monitoring bots—operate in some of the harshest environments on Earth. Whether submerged in saltwater, exposed to wave impact, or left tethered on marine platforms, these systems demand IP68-certified power supplies that can withstand continuous water exposure, high pressure, and corrosion.
IP68-rated equipment is both:
- Dust-tight (IP6X)
- Waterproof under continuous immersion (typically beyond 1 meter for extended durations)
In marine applications, this standard is not optional—it’s mission-critical. Failures caused by water ingress can lead to:
- Battery short circuits or thermal events
- Loss of propulsion or communication
- Complete mission failure or environmental hazards
For OEMs designing marine robotics, the power supply must be the most robust, sealed, and reliable component in the system. It must deliver regulated voltage and current under high salinity, variable pressure, and thermal load—without failure.
Top Features
- Fully potted or hermetically sealed AC-DC or DC-DC power supplies
- Wide input ranges to support battery or shore-powered modes
- Waterproof connectors with mechanical locking and shielding
Top Benefits
- Prevents downtime or recovery operations in inaccessible areas
- Ensures safe operation even in saltwater or brackish environments
- Enables long-duration missions with minimal service intervention
Best Practices
- Validate IP68 through pressure and immersion testing beyond standard minimums
- Use marine-rated materials (e.g., 316L stainless, UV-resistant polycarbonate)
- Isolate heat zones to prevent thermal degradation of seals or potting
Marine robot performance starts with watertight, power-stable engineering—and IP68 is your first line of defense.
Key Engineering Principles for IP68 Waterproof Power Supply Design
Designing to IP68 requires more than just applying sealant—it involves a fundamental rethinking of how the enclosure, internal layout, thermal dissipation, and cable interfaces all work together in a submerged or splash-prone environment.
Critical elements include:
- Full potting or resin encapsulation of internal electronics
- Use of marine-grade o-rings and gaskets with compression-tolerant geometry
- Selection of non-corrosive materials for housing, connectors, and mounting points
- Design for low internal air volume to prevent pressure differential issues
Unlike IP67 designs (which handle temporary immersion), IP68 units must survive long-term submersion and sometimes pressurization depending on depth. This adds strain to seals, vent membranes, and solder joints.
Thermal management is also different. In some cases, water acts as a coolant—so power modules can be designed to transfer heat outward through the enclosure wall. However, these surfaces must be isolated from the electrical system and carefully rated for both conductivity and insulation.
Top Features
- Fully sealed, molded resin units with no air gaps
- External heat sinking via the housing or interface plates
- Pressure-rated vent membranes for equalization without water entry
Top Benefits
- Ensures full waterproofing without relying on mechanical fasteners alone
- Increases MTBF in underwater and coastal deployments
- Minimizes weight and bulk with integrated thermal pathways
Best Practices
- Design with potting-first strategy, not retrofit sealing
- Select adhesives and sealants with chemical resistance to salt, algae, and UV
- Verify material performance at both room and marine operating temperatures
IP68 success begins with design—not testing. If it’s not watertight in CAD, it won’t be watertight in the field.
Managing Power Conversion and Thermal Load in Fully Sealed Systems
One of the biggest engineering challenges in IP68 power supplies is managing heat. In a fully potted or sealed enclosure, heat has nowhere to escape internally, and air can’t flow. In marine robotics—especially in battery charging or propulsion scenarios—thermal buildup is unavoidable.
Strategies include:
- Thermally conductive potting compounds to spread heat across the housing
- Overmolded heat fins or plates to transfer heat into the water directly
- Active thermal throttling or derating curves built into firmware
For DC-DC converters (used in underwater battery charging), peak efficiency must be >90%, and transient suppression must handle back-EMF from motors or prop-driven systems. For AC-DC modules (used in docking or tethered boats), full isolation and surge protection is mandatory due to harsh marine grids or generator noise.
Top Features
- Heat-spreading enclosures with embedded copper or aluminum planes
- Internal temperature sensors with real-time control
- Wide operating range: –20°C to +70°C or more
Top Benefits
- Protects sensitive components without opening or airflow
- Enables higher power density in waterproof form factors
- Prevents overheating during long missions or active charging cycles
Best Practices
- Validate thermal performance in submerged and surface conditions
- Model heat flow through potting and wall materials during design
- Include firmware-based derating curves for sustained operation
The best waterproof supply doesn’t just survive water—it manages heat like it’s underwater all the time.
CLIENT'S QUOTE
"Phihong’s PoE solutions have made a huge difference for us! Our network runs more efficiently, and we’ve seen real cost savings. We couldn’t be happier!"
Waterproof Connector and Cable Design for Submerged Use
Cables and connectors are the most common point of failure in IP68 systems. Even if the enclosure is flawless, a poorly sealed connector or cable can compromise the entire supply. That’s why marine-grade cabling and waterproof connectors are essential.
Use connectors rated for:
- IP68 or IP69K ingress protection
- Full submersion and locking engagement
- Resistance to salt corrosion, UV radiation, and temperature cycling
Standard options include:
- M12 circular connectors with o-ring seals and metal threads
- Subsea connectors for deeper immersion
- Overmolded cable harnesses with strain relief and epoxy seals
In addition, DC wiring should be:
- Double-insulated with tinned copper conductors
- Shielded to prevent EMI in long tethered runs
- Terminated with sealing glands or potted pigtails
For maximum durability, cables should be co-molded or fully integrated into the housing using IP-rated bushings and resin fills.
Top Features
- Saltwater-resistant cabling (IEC 60332, UL 1581-rated)
- UV-resistant sheathing with low flex fatigue
- Connector interfaces tested to ISO 20653 or MIL-STD-810
Top Benefits
- Prevents shorts and degradation even during full immersion
- Extends dock or charger cable life despite movement or strain
- Ensures long-term underwater performance in all conditions
Best Practices
- Avoid plug/socket systems in favor of hardwired or twist-lock types
- Conduct pressure tests on final cable assemblies
- Use only connectors rated for continuous submersion (not splash only)
Water always finds the weak point—don’t let it be your cable gland.
Testing and Certification for IP68 Compliance in Marine Robotics
True IP68 compliance requires more than just theoretical design—it must be proven through physical testing, both in-house and by third-party certification bodies. Most marine applications also require additional environmental and electrical tests beyond standard IP ratings.
Key certification processes include:
- Ingress protection testing (dust chamber + immersion tank)
- High-pressure jet and immersion cycling
- Thermal shock testing for temperature gradients (IEC 60068)
- Salt spray testing (IEC 60068-2-11) for corrosion resistance
- Electrical insulation resistance and hi-pot testing
Depending on end-use, your supply may also need:
- UL 62368-1 / IEC 60950 for power supply safety
- CE and UKCA marking for EMC and electrical compliance
- MIL-STD-810 or ISO 13628 for military or subsea systems
It’s also wise to validate vibration resistance, as marine systems face constant dynamic movement from wave action, propeller vibration, or hull flexing.
Top Features
- IP68 immersion validation beyond 1 meter, 30 minutes
- Certified ingress testing at different cable orientations
- Corrosion and salt-fog simulation
Top Benefits
- Ensures real-world readiness, not just datasheet compliance
- Accelerates time-to-market with pre-certified components
- Reduces support and warranty risk in harsh deployments
Best Practices
- Work with NRTLs like UL, Intertek, TÜV for validation
- Include in-house testing early during prototyping
- Require subassembly testing—not just whole-unit tests
Certification is your proof that a power supply isn’t just waterproof—it’s maritime-grade.
How Phihong USA Supports IP68 Power Supply Development for Marine Robotics
Phihong USA is a trusted global supplier of ruggedized power solutions for industrial and robotic applications—including autonomous maritime and underwater systems. We help OEMs meet the exacting requirements of IP68-certified, high-reliability, and corrosion-resistant power modules designed for marine environments.
We offer:
- IP68-rated DC-DC and AC-DC modules (250 W to 2 kW)
- Fully potted and heat-dissipating enclosures for submersion
- Marine-grade cabling and connector assemblies
- Smart charging interfaces with BMS communication
- UL, CE, and MIL-STD testing support
- Custom form factors for integrated or standalone charging
Whether you’re building underwater drones, moored data buoys, or amphibious robots, Phihong delivers mission-ready power systems with marine-proof durability and precision.
To start a design consultation, visit www.phihong.com or contact usasales@phihongusa.com.
Contact Our Team Today!
Our dedicated sales team and international partners are prepared to support you with your latest projects and initiatives globally.
Explore More with Phihong USA
As we conclude our exploration of PoE technology, it’s evident how these innovations are streamlining power and data integration across various industries. Phihong USA stands at the forefront of this technological advancement, offering a diverse range of power solutions designed to meet the evolving needs of modern industries.
Phihong USA’s extensive product lineup includes:
- Power over Ethernet (PoE) Solutions: Delivering reliable power and data transmission over a single cable, ideal for simplifying network installations and reducing costs.
- AC/DC Adapters and Power Supplies: From compact adapters to industrial-grade power supplies, Phihong provides solutions that ensure efficiency and reliability in various applications.
- Battery Chargers: Customizable chargers for lithium-ion and lead-acid batteries, supporting a wide range of power requirements for mobility and industrial applications.
- Medical Power Supplies: Specialized power solutions designed to meet the stringent requirements of the healthcare industry, ensuring safety and reliability.
Phihong USA is committed to innovation and excellence, continually developing products that meet the highest standards of performance and reliability. Their global reach and dedication to customer support make them a trusted partner in powering the future.
Here are some useful links to explore Phihong USA’s offerings further and bring in new potential clients:
Visit Phihong USA to discover how their advanced power solutions can support your business needs. Whether you’re looking to upgrade your network, or find reliable power supplies, Phihong USA has you covered.
By choosing Phihong USA, you’re partnering with a leader in power technology, ensuring your operations run smoothly and efficiently with top-tier power solutions. Contact Us today!
FAQ
What is the difference between IP67 and IP68?
While both IP67 and IP68 are ingress protection ratings, IP68 is the higher level of waterproofing. IP67 is rated for:
- Dust-tight protection (6)
- Temporary immersion in water up to 1 meter for 30 minutes (7)
IP68, on the other hand, allows for continuous immersion under conditions defined by the manufacturer—often 1.5 meters or more for extended time periods. For marine robotics, only IP68 is suitable for underwater missions or saltwater dock deployments. Phihong designs systems certified to IP68, with fully potted electronics and pressure-tested enclosures.
How do I know if a power supply is truly IP68-rated?
Look for a product that has:
- Third-party IP68 certification
- Fully sealed or potted internal electronics
- Certified waterproof connectors and cable glands
- Documentation showing immersion testing under pressure
Phihong provides test data and certifications on all IP68-rated products, ensuring compliance with global marine and robotics standards.
Can IP68 power supplies manage heat without airflow?
Yes, but it requires conductive thermal management. Phihong IP68 modules use:
- Thermally conductive potting compounds
- External aluminum housing for heat transfer
- Derating curves to reduce output power at high ambient temps
Some applications even use water as a passive cooling medium, helping dissipate heat through submersion.
Are there connectors that meet IP68 standards?
Yes—many circular connectors, overmolded harnesses, and twist-lock interfaces are rated IP68 or higher. Phihong uses:
- M12 and M23 sealed connectors
- Overmolded waterproof harnesses
- Custom potted cable ends with strain relief
These connectors are tested under immersion and salt spray conditions.
How does Phihong help OEMs build IP68 marine power systems?
Phihong supports marine robotics OEMs by offering:
- Rugged, fully sealed DC and AC power modules
- Marine-ready components, including potted trnsformers and capacitors
- Custom enclosure design for underwater or coastal mounting
- Compliance support for UL, IEC, CE, and ISO 13628
- Engineering resources to test, prototype, and certify faster
Our mission is to help you deploy waterproof power that performs under pressure—literally.
