Disclosure: As an Amazon Associate, we earn from qualifying purchases. If you click a link on this page and make a purchase, we may receive a small commission at no extra cost to you.
NOCO GCP2 Review: A Waterproof 15A AC Port Plug for Boats, RVs, Trucks, and Outdoor Power
Running an onboard battery charger, engine block heater, or outdoor outlet should not require opening a hood, hatch, or storage compartment every time you need power. The NOCO GCP2 gives you a cleaner way to add an exterior AC inlet to a vehicle, boat, trailer, RV, or equipment panel. This review explains what the GCP2 does well, where it has limits, and whether it is worth buying for your setup.
Our Verdict
Rating: 8.6/10
Best For: You need a simple 15A exterior AC inlet for an onboard battery charger, engine block heater, RV accessory, trailer, or marine power setup.
Bottom Line: The NOCO GCP2 is a compact, waterproof, flush-mount AC port with dual 18-inch extension cords, 14 AWG copper wiring, and a 15A/125V rating. It is easy to install, but it is still a pass-through inlet, not a full shore-power system with breaker protection.
| Specification | Detail |
|---|---|
| Brand | NOCO |
| Model | GCP2 |
| Product Type | AC port plug, power inlet socket, and waterproof electrical outlet receptacle box |
| Electrical Rating | 15A, 125V AC |
| Wire Gauge | 14 AWG copper wiring |
| Cord Design | Dual integrated 18-inch outdoor extension cords |
| Mounting | Flush-mount flanged inlet for a 2-inch hole |
| Compatibility | Type-B extension cords, onboard battery chargers, engine block heaters, outdoor outlets, vehicles, boats, trailers, RVs, and equipment |
| Material and Color | Black plastic body with rubberized pressure-fit cover |
| Weight | 9.6 ounces |
| Included Accessories | Three 1-inch self-tapping screws |
| Certification | UL approved |
| Warranty | 1-year limited warranty |
Key Takeaways
- The NOCO GCP2 is a 15A, 125V AC inlet designed to make exterior power access easier on cars, trucks, boats, RVs, trailers, and equipment.
- Its dual 18-inch outdoor extension cords give you two internal AC leads from one exterior port.
- The pressure-fit rubberized cover and waterproof receptacle design help protect the inlet when it is mounted outside.
- The flush-mount body installs into a 2-inch hole and uses three included 1-inch self-tapping screws.
- It is a strong choice for chargers and heaters, but it is not a replacement for a full marine or RV shore-power system.
What Is the NOCO GCP2?
The NOCO GCP2 is a 2-way AC port plug that works as a 125V power inlet socket with two integrated 18-inch extension cords. You mount the inlet on an exterior surface, then connect the internal cords to your charger, heater, or other compatible AC-powered device. For many vehicle and marine setups, that means you can plug in from the outside instead of opening a compartment.
NOCO positions the GCP2 as an accessory for onboard battery chargers, engine block heaters, outdoor electrical outlets, and similar power-access jobs. The 15A rating, 14 AWG copper wiring, and full-size AC prongs make it better suited to practical power delivery than a lightweight cable pass-through. Its value comes from convenience: you get one clean exterior port instead of a dangling extension cord.
The GCP2 sits in the middle of NOCO’s GCP AC port lineup. It gives you two AC cables, while the NOCO GCP1 uses one shorter 16-inch cable. That makes the GCP2 the better fit when you want to power two nearby devices from the same inlet or when the dual-cable layout better matches your charger placement.
Who It’s For
- You maintain a boat, truck, trailer, or RV and want exterior plug-in access for a NOCO Genius charger or similar onboard battery charger.
- You use an engine block heater and want a cleaner flush-mounted inlet instead of routing an extension cord through a grille or hood gap.
- You need a weather-resistant 15A AC pass-through for equipment, marine storage, or outdoor electrical access where a 2-inch mounting hole is practical.
Who Should Skip It
- You need a complete shore-power system with breakers, inlet wiring, and code-specific marine or RV protection.
- You need more than 15 amps, a 20A T-blade plug, or 12 AWG wiring for higher-demand equipment.
- You do not want to drill a 2-inch hole into your vehicle, boat, trailer, or enclosure.
Design and Build Quality
The GCP2 uses a low-profile flanged body, so the finished installation looks cleaner than an exposed loose extension cord. The exterior inlet sits flush against the mounting surface, while the dual 18-inch cords stay behind the panel. At 9.6 ounces, it is light enough for vehicle, trailer, and equipment panels without adding noticeable weight.
The pressure-fit rubberized cover is one of the most useful parts of the design. It helps seal the AC inlet when you are not plugged in, which matters for boats, trailers, and trucks that see rain, spray, dirt, or road grime. You should still choose the mounting location carefully, but the cover gives the port practical outdoor protection.
The body material is black plastic, which keeps the unit light and corrosion-resistant. The tradeoff is that it will not feel as heavy as a metal marine-grade inlet. For most battery charger and block heater uses, the lighter plastic build is a reasonable match for the product’s 15A rating and accessory-level role.
Power Rating and Wiring
The GCP2 is rated for 15 amps at 125 volts AC. That rating fits common household extension cords and many onboard chargers, block heaters, and outdoor power accessories. It should not be treated as a high-amperage RV shore-power inlet or a substitute for a professionally designed electrical system.
NOCO uses heavy-duty 14 AWG copper wiring inside the integrated cords. That wire gauge is a meaningful advantage over thinner light-duty cords because it supports stronger current flow within the unit’s 15A limit. The full-size AC prongs also help maintain a secure connection with compatible extension cords.
The GCP2 is designed for Type-B extension cords. For you, that means it works with the common grounded three-prong AC plugs used for many outdoor and garage power jobs. Match your extension cord to the load, keep connections dry, and follow the equipment manufacturer’s electrical instructions.
Waterproof Cover and Outdoor Protection
The waterproof design centers on the snap-style pressure-fit cap and rubber gasket. When the port is not in use, the cover protects the inlet face from the elements. That is useful on boats, work trucks, trailers, and outdoor equipment because the port may be exposed between charging sessions.
This protection does not mean you should submerge the inlet or ignore safe outdoor power practices. The GCP2 is best understood as a weather-resistant exterior access point for AC power. You still need a properly rated outdoor extension cord and a safe power source, especially around water.
For common use cases such as a battery maintainer on a parked boat or an engine block heater during cold weather, the cover makes day-to-day use much cleaner. You plug in when needed, unplug when done, then close the cap. That simple routine is the main reason the GCP2 is consistently well-reviewed by buyers who want exterior access without a messy cord setup.
How to Install the NOCO GCP2
Installation is straightforward because the GCP2 requires no hand wiring or cable modification. You choose a mounting spot, drill a 2-inch hole, insert the inlet, and secure the flange with the three included 1-inch self-tapping screws. The internal dual 18-inch cords then connect to your charger, heater, or compatible AC device.
| Step | Action | Why It Matters |
|---|---|---|
| 1 | Choose the mounting location | Keep the port accessible while avoiding moving parts, heat, and road debris |
| 2 | Drill a 2-inch hole | The flush-mount body is designed for this opening size |
| 3 | Insert the GCP2 and secure it | The included self-tapping screws hold the flange in place |
| 4 | Connect the internal cords | The dual 18-inch leads give you two nearby AC connection points |
Before drilling, check both sides of the mounting surface. You need room for the inlet body, the cord bend, and the connected plug ends. On boats and vehicles, you should also avoid structural supports, wiring harnesses, fuel lines, and areas that collect standing water.
How It Performs in Real Use
For Onboard Battery Charging
The GCP2 makes the most sense when paired with an onboard battery charger. You can mount the inlet near a bumper, hatch, compartment, or transom, then leave the charger connected inside. When it is time to maintain the battery, you plug your outdoor extension cord into the exterior port.
For Engine Block Heaters
For cold-weather vehicles, the GCP2 gives you a cleaner alternative to a loose block heater cord. The 15A/125V rating fits many block heater setups, but you should confirm your heater’s electrical requirements first. The flush-mounted cap also keeps the front of the vehicle neater when the heater is not connected.
For Boats, Trailers, and RV Accessories
On boats, trailers, and RVs, the GCP2 works well as a compact AC access point for low-demand accessories and battery maintenance. The waterproof cover helps protect the inlet between uses. It is especially useful when your charger or accessory sits inside a compartment that you do not want to open every time you plug in.
Pros and Cons
Pros
- 15A/125V AC rating fits many onboard chargers, block heaters, and outdoor power accessories.
- Dual 18-inch integrated cords give you two internal AC leads from one exterior inlet.
- 14 AWG copper wiring is more confidence-inspiring than thin light-duty extension wiring.
- Flush-mount design creates a cleaner exterior installation than a loose dangling cord.
- Pressure-fit rubberized cover helps protect the inlet from rain, dirt, and general outdoor exposure.
Cons
- It requires a 2-inch hole, so installation is not reversible without body or panel repair.
- The 15A limit is not right for higher-demand RV or marine shore-power systems.
- The black plastic body is practical, but it may not satisfy buyers who want a heavier metal inlet.
Is It Worth the Price?
The NOCO GCP2 is a strong value for the price if you need a clean exterior AC pass-through and do not want to build one from separate electrical parts. You are paying for a ready-made 15A inlet, dual integrated cords, a weather-protective cap, and a simple flush-mount installation. For battery maintenance and block heater access, that convenience is the main selling point.
It is not the right purchase if your project needs a breaker panel, a dedicated shore-power inlet, or higher-amperage wiring. In that case, the GCP2 is too simple by design. For everyday charger and heater access, though, it is a smart buy because it solves a specific problem with fewer parts and less wiring work.
How It Compares to Alternatives
The NOCO GCP1 is the simpler alternative if you only need one integrated AC cord and can work with a 16-inch lead. The GCP2 is the better choice when you want two 18-inch cords from one exterior inlet. For buyers who need longer reach, NOCO’s GCP1E and GCP1EX models extend the same basic idea into 6-foot and 12-foot single-cord options.
Compared with generic 20A 125V RV-style inlet plugs, the GCP2 focuses on easy 15A plug-and-play use rather than higher-capacity service. A 20A model may be better for a system designed around 20A equipment, but it often uses a different plug style and heavier wiring. The GCP2 remains the cleaner pick for standard grounded extension cord use with chargers, block heaters, and light outdoor AC access.
Customer Feedback and Common Owner Impressions
Buyer feedback around the GCP2 commonly centers on easy installation, a clean finished look, and practical durability. Those strengths match the product’s design: it mounts in a 2-inch hole, uses included self-tapping screws, and keeps the plug face protected with a rubberized cover. For many owners, the biggest benefit is not raw power, but cleaner access to the power they already use.
Common praise also fits the use cases NOCO lists for the product. Battery charger users like being able to plug in without opening a hood or compartment. Boat, RV, and trailer owners tend to value the low-profile exterior cap because it looks neater than a loose cord and keeps the inlet protected between uses.
Warranty and Return Notes
The GCP2 carries a 1-year limited warranty according to the live Amazon listing. Amazon also lists a 30-day refund or replacement return window for the item in its original condition. Warranty and return terms can change, so you should review the seller’s current policy before purchasing.
Frequently Asked Questions
Is the NOCO GCP2 waterproof?
The GCP2 uses a pressure-fit rubberized cover and rubber gasket to help protect the AC inlet from outdoor exposure. It is a weather-protected inlet for rain, spray, and dirt, not a part you should submerge or install where standing water collects.
How long are the integrated cords?
The GCP2 uses dual integrated 18-inch outdoor extension cords. That length is meant for nearby internal connections, such as an onboard charger or block heater lead behind the mounting panel.
Can you use the NOCO GCP2 indoors?
Yes, you can use it indoors if the installation matches your electrical needs and local requirements. Its main advantage is outdoor access, so most buyers use it on vehicles, boats, trailers, RVs, equipment, or exterior-facing panels.
Does the NOCO GCP2 require wiring?
No hand wiring is required for a basic installation. The unit includes integrated cords, so you mount the inlet and connect those cords to compatible AC-powered equipment inside the compartment.
What is the difference between the NOCO GCP1 and GCP2?
The GCP1 has one 16-inch integrated cord, while the GCP2 has two 18-inch integrated cords. Choose the GCP2 if you want two internal AC leads from a single exterior inlet.
Can the GCP2 power an RV shore-power system?
The GCP2 is not a full RV shore-power system. It is a 15A, 125V pass-through inlet, so it works best for chargers, heaters, and similar accessories rather than full RV electrical service.
The Bottom Line
The NOCO GCP2 earns an 8.6/10 because it solves a real access problem with a compact 15A design, dual 18-inch cords, 14 AWG copper wiring, and a weather-protected cover. You should buy it if you want a cleaner exterior plug-in point for a battery charger, engine block heater, boat, trailer, truck, or RV accessory. You should skip it if your project needs higher amperage, breaker protection, or a full shore-power installation.
Ready to Buy?
