Infrastructure & Storage Application

EV Charger Humidity Protection IP65+

Q: How do I know if my EV charger has active or passive thermal regulation?

Three quick criteria: power (≤ 22 kW AC = passive standard; ≥ 50 kW DC = active), visible ventilation events (extraction fan or air grilles signal active), and noise during charging (DC fast emits perceptible ventilation noise, AC is silent).

Q: Does the a French EV charging operator 85-day study apply to all EV chargers?

No — only to passively-cooled IP65 chargers (AC wallboxes 3-22 kW). For DC fast charging with forced ventilation or liquid cooling, AS-C deploys on separate control compartment only, case-by-case study.

Q: Performance in cold climate at -20°C (Scandinavia, mountain, Canada)?

AS-C operating range: -20°C to +70°C. Capillary adsorption mechanism works perfectly in cold climate — actually the climate where day/night dew point gap is most violent. For premium chargers in extreme climates with integrated heating resistor, AS-C reduces the resistor load and associated electricity OPEX.

An IP65 AC wallbox that goes into fault on a winter morning means a user who can't charge, an O&M called out urgently, and — across a fleet — dozens to hundreds of annual incidents that erode your network's contractual availability.

The AS-C tape protects the internal air of EV chargers with passive thermal regulation: residential and commercial AC wallboxes (3-22 kW). For DC fast charging stations, AS-C scope is limited to the separate control compartment. Direct validation by the a French EV charging operator 85-day field study on 3 IP65 chargers.

8× usable capacity zone 60-90% RH 0 W consumption IEC 61851 / IEC 62196 compatible scope-direct (passive AC IP65)

Request free samples Quote AS-C Request information

Why outdoor EV chargers suffer

Permanent thermal cycling on a rapidly densifying fleet

The European EV charging fleet has gone from a few thousand to hundreds of thousands of stations in a few years. An outdoor EV charger — residential wallbox (3-7.4 kW), commercial public charger (11-22 kW), or DC fast charger (50-400 kW) — is exposed to severe permanent thermal cycling in non-climate-controlled environments.

By day, the charger heats up under combined effects of direct sunlight and thermal output of power components during charging sessions. At nightfall, rapid cooling. Internal pressure drops, and outdoor air loaded with water vapor flows back through micro-leaks at door gaskets, AC/DC cable glands, and Type 2 or CCS connectors.

Over 10-15 years of nominal lifetime, this represents more than 4,000 cumulative thermal cycles — far beyond the resilience of factory calcium chloride packs.

Three cumulative damages CPOs underestimate

1. Insulation faults detected by firmware

Internal humidity on HV traces can trigger PE Fault, Earth Fault, or RDC-DD fault detected by mandatory residual-current protection modules. Result: the charger goes into fault and refuses charging sessions until humidity evaporates. On a public fleet, this means degraded contractual availability.

2. Corrosion on Type 2/CCS connectors, contactors, metering modules

Copper/silver/gold contacts oxidize progressively. Result: increased contact resistance, local heating during charging, premature thermal trip, and — in advanced cases — Type 2 connector degradation visible to user.

3. Accelerated aging of control and communication electronics

OCPP controllers (4G/5G modem + CPU + SIM card), LCD displays, RFID/NFC readers see lifetime divided by 1.5 to 2 in humid environment.

Operational cost

Operational cost on a deployed EV fleet

For a CPO or B2B EV operator, real cost = network availability + field service OPEX + lost transaction revenue + CSRD impact.

4,000+

cumulative thermal cycles

Over 10-15 years, passive regulation

$165-880

per truck roll on remote charger

PTC Field Service, SightCall

99-99.5%

contractual availability

Required by public buyers & B2B

3-5% / yr

humidity-related failure rate

IP65 fleets without protection

On a fleet of 1,000 public AC chargers at a CPO:

Avoidable humidity-related truck rolls: ~3% per year = 30 avoidable interventions/year = $5,000-26,000 OPEX/year
Lost transaction revenue during outages: tens of thousands of USD/year
Contractual SLA penalties with concession authority
Early renewal of corroded Type 2 connectors: $165-330/connector + labor

On a 10,000 wallbox B2C residential fleet from an EV installer:

Warranty SAV interventions: very profitable to reduce frequency
Brand image and NPS impacted by repeated incidents

Structural question

Thermal regulation mode — critical for AS-C scope

Does your EV charger have passive thermal regulation (natural cooling) or active (forced ventilation, even liquid cooling)? AS-C delivers different value in both cases.

1. Passive AC chargers — AS-C optimal scope

No active integrated system. The charger relies on IP sealing, pressure equalization vents, and natural convection thermal dissipation. This is exactly the context of the a French EV charging operator 85-day study.

Concerned chargers: Residential AC wallboxes 3-7.4 kW (Wallbox Pulsar Plus, Schneider EVlink, Hager Witty, Easee Home, Zaptec, Tesla Wall Connector, ChargePoint Home Flex, JuiceBox 40, Enphase IQ EV Charger), Commercial AC wallboxes 11-22 kW (Wallbox Commander 2, Schneider EVlink Pro AC, ABB Terra AC, Hager Witty Park, Easee Charge, ChargePoint CT4000, Blink Series 7), pole-mounted parking chargers, multi-unit residential chargers.

→ scope-direct study: ÷ 2.6 on time spent in condensation zone.

2. Chargers with partial active regulation — AS-C complementary

Localized forced ventilation (typically an extraction fan), but no full internal volume climate control. AS-C complements by acting on internal air humidity in zones not swept by forced airflow.

Concerned: high-end AC wallboxes with small extraction fan, entry-level DC chargers 25-50 kW with moderate ventilation, certain 22 kW commercial chargers in extreme climates.

→ AS-C reduces fan trigger cycles → reduced electricity OPEX, extended fan lifetime.

3. DC fast charging with full active regulation — AS-C limited scope

Mandatory active cooling (forced ventilation, heatsinks, sometimes liquid cooling for 150+ kW ultra-fast). Power compartment generates 5-15 kW heat at nominal. AS-C delivers no value on the climate-controlled power compartment, but can remain relevant on the separate control compartment.

Concerned: DC fast 50-150 kW (ABB Terra DC, Schneider EVlink Pro DC, Tritium PKM 150, ChargePoint Express, Tesla Supercharger V2, EVgo Fast, Electrify America 150), DC ultra-fast 150-400 kW (ABB Terra HP, ChargePoint Express Plus 350, Kempower 400, Tesla Supercharger V3/V4, IONITY HPC 350), multi-station central power cabinets.

→ Case-by-case study mandatory. AS-C scope typically reduced to separate control compartment.

Charger type	Thermal regulation	AS-C scope
Residential AC wallbox (3-7.4 kW)	Passive	✓ Optimal — scope-direct
Commercial AC wallbox (11-22 kW)	Passive	✓ Optimal — scope-direct
Pole-mounted parking AC	Passive	✓ Optimal
Underground residential charger	Passive	✓ Optimal
AC high-end with fan	Partial active	✓ Complementary
Entry DC 25-50 kW	Partial active	✓ Complementary
DC fast 50-150 kW	Full active	⚠ Control compartment only
DC ultra-fast 150-400 kW	Full active (often liquid)	⚠ Control compartment only
Multi-station central cabinet	Full active	⚠ Control compartment only

Not sure of your fleet's regulation mode? So Sponge offers a rapid qualification sheet (3-5 visual and technical criteria). Request the sheet →

State of the art

Why current solutions don't work (on passive AC chargers)

Calcium chloride salts (Rubson, Wisedry, Damprid)

Default solution from most AC OEMs (Schneider EVlink, Hager Witty, Wallbox, Easee, Zaptec, Legrand). Pack 5-30 g integrated at factory.

Saturated within 6-12 months on an exposed outdoor charger
Never replaced once the charger is installed
Designed for transport and the first year

→ AS-C addresses this exact pain point on passive chargers.

Pressure equalization vent

Found on modern IP65/IP66 EV chargers. Limits mechanical stress on gaskets under thermal cycling.

Doesn't control internal humidity: water vapor passes through the membrane
field study confirms: on 3 passively-cooled IP65 chargers, breather alone doesn't reduce internal/external RH correlation

→ AS-C and pressure vents are complementary.

Resistive heater + hygrostat

Solution on a few high-end chargers deployed in cold climates (Scandinavia, mountain, Canada).

Consumes 30-200 W (~30% real duty cycle) = significant electricity OPEX over 10-15 years
Electromechanical component = additional point of failure
Generates a thermal load constraining overall thermal balance

→ AS-C advantageously replaces this approach in temperate climates.

Note on active solutions in DC fast charging compartment

DC fast chargers (50+ kW) have mandatory active cooling for power module heat evacuation — it's a safety requirement, not an option. AS-C does not replace this cooling. It only adds to the separate control compartment for residual humidity.

See full comparison of 4 large-volume solutions →

Charger type	Internal volume	Recommended format
Compact residential AC wallbox 3-7.4 kW	5-15 L	AS-B/L sticker (40 cm²) or short AS-C
Commercial AC wallbox 11-22 kW	15-40 L	AS-C tape (sized surface)
Pole-mounted parking AC	30-100 L	AS-C tape
Multi-unit residential underground	10-30 L	AS-B/L or AS-C by volume
Premium 22 kW AC + comm module	30-80 L	AS-C tape

Integration

How to integrate in practice

Residential AC wallbox (passive)

AS-B/L sticker (40 cm²) or short AS-C tape bonds to inner front cover, away from power module and energy meter. Application time: under 1 minute.

Commercial 11-22 kW AC wallbox (passive)

AS-C tape (5-8 cm width, 30-60 cm length by volume) bonds to main inner wall, away from hot components, ideally upper area. Application: 2-3 minutes.

Pole-mounted parking AC charger (passive)

Apply AS-C tape in the main top compartment (where electronics concentrate). For two-compartment chargers (top + base power supply), AS-C in both, prioritizing top electronics compartment.

DC fast 50-150 kW — control compartment only

For a DC fast charger, AS-C deployment is limited to the separate control compartment not swept by forced airflow (typically communication / screen / RFID / energy metering compartment). The active-cooled power compartment doesn't need AS-C. Joint technical study So Sponge + manufacturer engineering team recommended.

Scope-direct proof

field study — scope-direct proof on passive AC

The field study is the most directly applicable So Sponge field proof for passively-cooled AC EV chargers: 3 outdoor IP65 EV chargers, 85 days, 24,385 measurements, winter 2025/2026.

Metric	Control charger	AS-C charger	Ratio
Time in condensation zone	Reference	Reduced 2.6×	÷ 2.6
Internal RH variability	Reference	Reduced 3×	÷ 3
Internal/external RH correlation	0.54	0.02	27× more stable

Difference vs other So Sponge proofs: this is not a climate chamber lab test, it's a real-conditions field study. For passively-cooled outdoor AC EV chargers, this is direct validation without extrapolation.

Read the full field study →

FAQ

EV chargers and anti-condensation

How do I know if my EV charger has active or passive thermal regulation?

Three quick criteria: (1) power — all ≤ 22 kW AC chargers are passive standard; ≥ 50 kW DC are active; between 22 and 50 kW it varies; (2) visible ventilation events — visible extraction fan or air grilles signal active regulation; (3) noise during charging — DC fast in session emits perceptible ventilation noise, AC wallbox is silent. So Sponge provides a detailed qualification sheet on request.

Does the a French EV charging operator 85-day study apply to all EV chargers?

No — only to passively-cooled IP65 chargers (typically AC wallboxes 3-22 kW). For DC fast charging with forced ventilation or liquid cooling, the study is not directly extrapolable — AS-C deploys on separate control compartment only, case-by-case study.

My commercial AC wallboxes (11-22 kW) show winter peaks of insulation faults. Can AS-C really change that?

Yes, provided wallboxes are passively cooled — which is the case for nearly all commercial AC market models (Wallbox Commander, Schneider EVlink Pro AC, ABB Terra AC, etc.). field study on 3 IP65 chargers demonstrates ÷ 2.6 on time spent in condensation zone. Retrofit immediately stabilizes future performance.

Is AS-C compatible with RDC-DD type B protection?

Yes without any interaction. AS-C is a passive consumable with no electrical, mechanical, or software interaction. On the contrary, by eliminating internal condensation, AS-C reduces nuisance tripping of RDC-DD type B protection (sensitive to humidity-induced leakage currents).

Compatibility with IEC 61851 and IEC 62196 standards?

No incompatibility. These standards cover safety and communication requirements between vehicle and charger — they don't specify anti-condensation accessory composition. SRD material is passive, inert, REACH and RoHS compliant.

On my DC fast 100 kW charger — does AS-C provide value?

Case-by-case study. On the actively-cooled power compartment, AS-C provides no value — active regulation already maintains RH below 60%. However, the separate control compartment (OCPP modem, user screen, RFID reader, energy metering unit) is typically not climate-controlled and AS-C remains fully relevant there. Joint technical study with your engineering team recommended.

What about my 5-year-old wallbox fleet?

Retrofit possible as preventive intervention. AS-B/L sticker or AS-C tape bonds to deployed charger during routine maintenance. Retrofit prevents further degradation and stabilizes future performance, without repairing existing corrosion. Typical estimated ROI: 2-3 years.

Does AS-C void my AC manufacturer's IP65 warranty?

No. AS-B and AS-C are passive accessories placed inside the compartment, with no modification of external enclosure or sealing gaskets. IP65 warranty preserved. For large-scale deployments, prior notification to manufacturer is recommended best practice.

Performance in cold climate at -20 °C (Scandinavia, mountain, Canada)?

AS-C operating range: -20 °C to +70 °C. Capillary adsorption mechanism works perfectly in cold climate — actually the climate where day/night dew point gap is most violent. For premium chargers in extreme climates with integrated heating resistor, AS-C reduces the resistor load and associated electricity OPEX.

CSRD and carbon reporting: does AS-C provide an argument on scope 3?

Yes. By extending charger lifetime and reducing failure rate, AS-C reduces component renewal frequency — therefore reducing carbon footprint reported annually under scope 3. Relevant argument for CPOs and EV operators subject to CSRD.