Introduction To Selecting Outdoor Waterproof Housings for Charging Stations – IP Rating, IK Impact Resistance, And Material Comparison

This article covers the following content

This article is aimed at charging station operators (CPOs), charging station manufacturers (OEMs/ODMs), new energy EPC contractors, and electrical wholesalers, helping you quickly grasp the key points of selecting outdoor waterproof casings for charging stations in 10 minutes:

1. 5 unique challenges - Why can't ordinary waterproof junction boxes be used for charging stations?

2. How to choose an IP level - The real significance of IP65, IP66, and IP67 in charging pile scenarios

3. IK impact resistance rating - Why must public charging stations be designed to prevent them from being smashed?

4. Comparison of three materials - How to choose between PC, SMC fiberglass, and stainless steel?

5. Selection Decision Tree + Comparison Table - Lock in the solution in 3 seconds based on project type

This article was written by the BSUMWELL technical team. We are a source manufacturer specializing in outdoor waterproof casings for charging stations. Our products cover materials such as UV-resistant PC, SMC fiberglass, and 304/316 stainless steel, with a full range covering IP65/IP66/IP67 protection ratings. OEM customization is supported. Certain models are available with an IK10 impact resistance rating to meet the safety requirements of public charging scenarios.

1. Why can't ordinary waterproof junction boxes be used for charging stations? — 5 unique challenges

If you've ever worked on a charging station project, you've probably seen this scenario: a roadside charging station that, after two years of use, has a yellowed casing, broken hinges, a blurry display window that makes it impossible to read the readings, or even water damage to the casing that causes it to stop working.

Upon opening it up, it turned out to be a standard outdoor waterproof junction box—IP65 rated, made of ABS plastic, and looked "quite sturdy."

The problem is that ordinary waterproof junction boxes are not designed for charging stations.

The usage scenarios faced by the casing of a charging station are far more severe than those of a regular junction box that is "mounted on the wall and occasionally gets rained on." If it fails to withstand any of the following five challenges, the entire charging station will have to be scrapped prematurely.

1.1 Five common problems with ordinary waterproof cases

1. Sun and rain exposure - insufficient UV protection
   Ordinary ABS plastic shells begin to yellow, powder, and become brittle after 2-3 years under direct sunlight. Their impact resistance decreases by more than 50% (based on the UL 746C long-term aging test standard), and they crack with the slightest touch.
   The design life of a charging station is 8-10 years. Using a regular ABS shell means the shell will fail before the project even recoups its costs.

2. Human-caused damage – lack of IK impact-resistant design
   Public charging stations are unattended. Lock-breaking, door-prying, wire-pulling, and even simple vandalism happen every day.
   Ordinary waterproof junction boxes lack impact resistance design, and their IK rating is typically below IK07. They break easily with a single impact, exposing live parts and posing a significant safety hazard.
   For charging stations installed in public areas, IK10 is an important safety threshold. Our series of dedicated charging station housings includes certain models available with an IK10 impact resistance rating, specifically designed for unattended public charging scenarios.

3. Continuous overheating – lack of heat dissipation design
   Charging stations are not devices that are "connected occasionally." It is normal for AC slow charging stations to work continuously for several hours, while DC fast charging stations operate under high load around the clock.
   The temperature inside the sealed enclosure can be 20-30°C higher than the ambient temperature (based on industry-standard data from charging pile thermal testing). In summer, when the ambient temperature is 35°C, the temperature inside the enclosure can reach 60-65°C. Ordinary waterproof junction boxes lack heat dissipation design, causing internal components to operate at high temperatures for extended periods, significantly shortening their lifespan.

4. Moisture intrusion – condensation-free protection
   The design logic of a typical waterproof junction box is to "keep water out." However, the problem with charging stations is that moisture is generated inside.
   The temperature difference between day and night causes a "breathing effect" inside the casing—it expands during the day and contracts at night, drawing in external moisture through the gaps in the sealing strip. The moisture condenses into water droplets inside, which can cause a short circuit if they drip onto the circuit board.

5. Frequent operation – insufficient durability of hinges/locks
   A typical waterproof junction box might be opened once or twice a year. But what about charging stations? They might be opened several times a day for maintenance personnel to inspect them, for users to reset emergency buttons, and for checking meter readings.
   Ordinary hinges and door locks will loosen, deform, and fail to close properly within 1-2 years under such frequency. The seals will fail, and the protection level will drop to zero.

Our dedicated charging station housing series is specifically designed to address the five challenges mentioned above—utilizing UL746C f1 UV-resistant material, reinforced hinges and locks, and an integrated ePTFE waterproof and breathable valve—with certain models offering an IK10 impact resistance rating to meet safety requirements in public charging environments.  If you require the IK10 model, please specify this when selecting the model.。

2. IP Protection Rating and IK Shock Resistance Rating Selection – A Dual Threshold for Charging Pile Housings

When selecting a charging station casing, there are two numbers that must be understood: IP rating and IK rating.

IP rating refers to whether it is waterproof and dustproof, while IK rating refers to whether it is impact-resistant. Only when both standards are met can a charging station be used outdoors.

2.1 IP rating – How to choose between IP65, IP66, and IP67 in charging station scenarios?

IP (Ingress Protection) rating is an internationally recognized protection standard (based on IEC 60529). The first digit represents dustproof, and the second digit represents waterproof. When purchasing charging stations, the second digit (waterproof) is the primary consideration.

How to choose? Based on the scenario:

• AC slow charger (wall-mounted/pole-mounted): IP65 is the starting point, IP66 is even more reliable. Wall-mounted bollards are usually in open or semi-open environments, and direct exposure to heavy rain is common.

• DC fast charging (floor-standing cabinet): IP54/IP55 is common (because heat dissipation and ventilation are required), but it needs to be combined with an internal moisture-proof design. If installed in a coastal or humid area, IP65 or higher is recommended.

• underground parking garage: IP65 is sufficient. Underground parking garages are not directly exposed to heavy rain; the real challenge is preventing condensation rather than waterproofing (see subsequent articles for details).

• Coastal/low-lying areas: IP66 or IP67 is recommended. Only IP66 or higher can withstand the torrential rain and short-term flooding brought by typhoons.

Our charging station casings are available in IP65, IP66, and IP67 ratings, allowing for flexible selection based on project requirements. [View the charging pile casing product series]

2.2 IK Rating – Why must public charging stations consider impact resistance?

IP rating governs "water," while IK rating governs "smashing."

What is the IK level? The IK rating is the shock resistance rating of an enclosure as defined by the IEC 62262 standard. A higher number indicates greater shock resistance.

Why is IK rating more important than IP rating in charging station scenarios?

A harsh reality: public charging stations are unattended. Lock-breaking, door-prying, forcibly pulling the charging cables, drunkards kicking them – these things happen every day.

• IK08 (5J): It can handle common accidental collisions (such as minor scrapes while reversing).

• IK10 (20J): It can withstand deliberate impacts (such as being hit hard with a hammer or brick).

Risks of low IK level: Damaged casing → Exposed live parts → Risk of electric shock to user → Liability of operator for compensation.

Many charging station project tender documents explicitly require "shell IK10". If your shell does not meet this standard, you are not even eligible to bid.

Our charging pile casing product line includes certain models available with an IK10 impact resistance rating, capable of withstanding the impact of a 5kg steel ball falling freely from a height of 400mm (based on IEC 62262 standard), meeting the safety requirements of unattended public charging scenarios. If your project requires IK10, please specify this when selecting a model.

3. Selection of Casing Material – Comparison of Advantages and Disadvantages of PC, SMC, and Stainless Steel in Charging Pile Scenarios

Material selection is one of the most crucial decisions in the procurement of charging pile casings. PC, SMC fiberglass, and stainless steel each have their own advantages and disadvantages. Choosing the right material saves money and hassle, while choosing the wrong one can lead to endless troubles.

3.1 Material Selection Decision Tree – 4 Steps to Lock in Material Direction

Follow these four steps to evaluate each option and find the material that best suits your project:

• Step 1: Is the project located in a coastal mudflat or high-salt fog environment (within 2 kilometers of the coastline)?

• ✅ yes → 316 stainless steel or corrosion-resistant PC

• ❌ no → Proceed to step 2

• Step 2: Is the charging station DC fast charging (which generates a lot of heat) or AC slow charging?

• ✅ DC fast charging → Stainless steel or aluminum alloy (heat dissipation is preferred, as metals have good thermal conductivity)

• ❌ AC slow charging → Proceed to step 3

• Step 3: Is it installed in a public area (which poses a risk of malicious damage)?

• ✅ yes → SMC fiberglass or stainless steel (impact resistance preferred)

• ❌ no → Proceed to step 4

• Step 4: Pursuing lightweight design and cost-effectiveness?

• ✅ yes → UV-resistant PC (lightweight, cost-effective, and with good insulation)

• ❌ no → Standard PC/ABS or SMC are both acceptable

Our charging pile casing series covers three major material options: UV-resistant PC, SMC fiberglass, and 304/316 stainless steel—whether your project is located along the coast, by the roadside, or in an underground parking garage, there is a corresponding material option. If you require an IK10 impact resistance rating, please specify this when selecting a model, and we will recommend the appropriate version.

3.2 UV-resistant PC – the first choice for AC slow charging and wall-mounted applications

PC (polycarbonate) is one of the most commonly used materials for charging pile casings, but not all PCs are the same.

• Advantage: Lightweight (low load-bearing requirements for wall mounting), cost-controllable, good insulation (no grounding required), transparent viewing window optional.

• Shortcoming: Impact resistance is not as good as SMC; long-term UV exposure requires a special formula.

• Key Certification: UL 746C f1 (Outdoor UV Protection Certification) – Ordinary PC does not have this certification, and it will yellow and become brittle after 2-3 years of outdoor use.

Differences between regular PCs and UV-resistant PCs:

Ordinary PC yellows, powders, and loses more than 50% of its impact resistance after 3 years outdoors. UV-resistant PC (UL 746C f1 certified) passes 1000 hours of xenon lamp ultraviolet exposure and water immersion tests (based on UL 746C f1 certification standards), ensuring that it will not yellow or become brittle for more than 10 years.

Material identification tips: When purchasing, you can ask the supplier, "Does your PC casing have UL 746C f1 certification?" - This question can filter out most low-priced and inferior products.

Our PC series charging piles use UL 746C f1 certified UV-resistant polycarbonate for the casing, ensuring no yellowing or embrittlement for over 10 years in outdoor environments. Please contact customer service for certification.

3.3 SMC Fiberglass – The Impact Resistance Champion for Roadside Charging Stations and Public Charging Scenarios

SMC (sheet molding compound) fiberglass is the "standard answer" for roadside public charging stations.

• Advantage: High strength, excellent weather resistance (virtually unaffected by UV radiation), and good flame retardant properties (UL94 V-0).

• Shortcoming: Higher cost than PC, limited color options, heavier than PC

• Applicable Scenarios: Roadside parking spaces, unattended public parking lots, and scenarios that may be subject to malicious damage.

SMC's weather resistanceAlmost unaffected by UV rays, requiring no maintenance for 25 years. Under outdoor exposure, SMC will not yellow like PC or rust like metal.

Our SMC fiberglass charging pile housing series is designed specifically for roadside public charging scenarios. Certain models are available with an IK10 impact resistance rating, suitable for unattended charging stations vulnerable to vandalism. Please specify if you require the IK10 model when selecting a model.

3.4 304/316 Stainless Steel – The King of Heat Dissipation for DC Fast Charging and Coastal Applications

Stainless steel has the best thermal conductivity of the three materials. For devices like DC fast charging stations that generate a lot of heat, a metal casing is a safer choice.

• 304 stainless steel: Suitable for general coastal environments (more than 2 kilometers from the coastline).

• 316 stainless steel: Suitable for environments with heavy salt spray (within 2 kilometers of the coastline, island projects).

The core advantage of stainless steel is Maintenance-free throughout the entire life cycle —No need for painting, no need to worry about corrosion, no need for replacement.

An easily overlooked detail:Fasteners must also be made of stainless steel. In many projects, the boxes are made of 304 stainless steel, and the screws are galvanized—five years later, the boxes are still intact, but the screws have rusted and broken.

We offer 304 and 316 stainless steel charging station housing options, suitable for DC fast charging and coastal/high salt spray environments. Material certification (MTC) can be provided upon project requirement.  [Learn more about 304/316 stainless steel charging pile casing]

3.5 Understanding the Three Major Materials in One Chart – Selection Comparison Table

How do I use this table?

1. Confirm your installation scenario (wall-mounted/roadside charging station/DC fast charging/coastal area)

2. Find the corresponding recommended material in the table.

3. Confirm that the key parameters of the material meet the project requirements (weight/impact resistance/heat dissipation/cost).

4. For IK10 impact resistance rating or NEMA rating/special customization, please contact customer service to confirm available models.

Note: IK10 is an optional feature for specific models and is not standard across the entire series. Please specify if you require IK10 when selecting your model.

The above selections are general suggestions only. For support on selections specific to your project, please contact our technical team for professional advice.  [Contact us for free product selection advice]

Frequently Asked Questions (FAQ)

Q1: How much difference is there between IP65 and IP66 in charging station scenarios?

A：IP65 is resistant to low-pressure water jets and can handle ordinary rain, but cannot be directly sprayed with a high-pressure water gun; IP66 is resistant to strong water jets and can withstand heavy rain and high-pressure water gun cleaning. IP65 is the starting point for AC slow charging stations, while IP66 is recommended for outdoor public charging stations.

Q2: How to choose between PC casing and stainless steel casing?

A：Consider two factors: power and location. For AC slow charging and wall mounting, choose PC (lightweight, low cost, good insulation); for DC fast charging and coastal environments, choose stainless steel (good heat dissipation, corrosion resistance). For the intermediate scenario of "roadside public charging stations," SMC fiberglass is a balanced choice (weather resistance + impact resistance).

Q3: Is IK10 required for all charging stations?

A：No. For indoor garages and scenarios with dedicated personnel, IK08 is sufficient. However, for open-air public parking lots and unattended roadside bollards, IK10 is an important safety threshold—some tender documents will explicitly require it. If you are unsure about project requirements, it is recommended that you consult the supplier to see if they offer an IK10 model when selecting a product. Certain models in our product line are available with an IK10 impact resistance rating.

These are the three steps to getting started with selecting a charging pile casing: understanding the five major challenges, choosing the right IP/IK rating, and deciding on the material direction.

Material and protection selection complete? Next, we need to solve the two most critical engineering challenges for the charging pile's casing: heat dissipation and condensation prevention. How to dissipate heat from the sealed casing? How to address the "breathing effect" caused by day-night temperature differences? Please read the next article:

[Design Guidelines for Heat Dissipation and Anti-Condensation of Charging Pile Casings—From Passive Heat Dissipation to Intelligent Microenvironment Control]

[Contact us for selection advice]