It is the charger’s brain, hanging on the cable. IC-CPD stands for in-cable control and protection device: the sealed box between the wall plug and the car that checks the connection, tells the car how much current it may draw, and cuts power on a fault. Without it, a portable charging cable would be just a cable — and it is not allowed to be just a cable.
Key Takeaways
- The box on a portable charging cable is the IC-CPD: the in-cable control and protection device.
- It signals the available current, checks the connection before power flows, and cuts power on a fault.
- Your charger’s current settings live in the box; the car still decides how much it takes.
- The cord set is one listed unit — support the box, keep it out of standing water, and never open it.
Why the Box Exists at All
A wall socket has no idea that a car is attached to it. Left alone, it would simply supply whatever is drawn, with no conversation and no supervision. The IC-CPD adds both. Through a signal wire in the cable it announces how much current is on offer, waits for the car to confirm it is properly connected, and only then switches the power through. That conversation and supervision are what make a portable cord set charging equipment rather than an extension lead with a car plug on the end — the distinction our portable EV charger buying guide assumes throughout.
What Happens Inside the Box
- Signalling. The box advertises the charging current you set, and the car agrees before any power flows.
- Connection checks. The connector stays unpowered until the box is satisfied the car is connected properly, so a loose plug is not live.
- Fault monitoring. The box watches the session and cuts the power if it detects a fault.
- Temperature sensing. On many designs the box also keeps an eye on heat at the wall plug, the end that works hardest.
- The controls you touch. The status light and, on adjustable chargers, the current-setting button live on the box.
| Part of the cord set | Its job |
|---|---|
| Wall plug | Takes power from the outlet — NEMA 14-50P on larger portables, a household plug on basic cords |
| Control box (the IC-CPD) | Signalling, connection checks, fault protection and the current setting |
| Cable | Carries power and the signal; its length decides your reach |
| Vehicle connector | Locks into the car’s charge port — J1772, NACS or Type 2 depending on the model |
Two EVDANCE Cord Sets, Read by Their Boxes
The settings on the box are the settings of the charger. On the EV-ACS3210T 32A NACS portable charger, the box steps the offer from 10 to 32 A in six steps (about 7.7 kW at the top, NEMA 14-50P, IP66). On the EV-AC04001U 40A J1772 portable charger, it selects 16, 24, 32 or 40 A (9.6 kW, NEMA 14-50P, IP66, 25 ft cable). In both cases the car then takes up to its own limit — the box offers and supervises, the car decides. That is also why the box is not the charger in the conversion sense: AC power passes through it, and the car’s onboard charger turns it into the DC the battery stores — as our explainer on charging from a normal socket sets out.
Living With the Box
Three habits keep it out of trouble. Support it while charging, so its weight does not hang off the plug or strain the cable ends. Keep it out of standing water and off ground where it can be driven over, IP66 rating or not. And treat its signals as final: a box that trips and will not reset, runs genuinely hot, or shows a damaged case is a charger to stop using until the manufacturer advises. There are no user-serviceable parts inside.
Frequently Asked Questions
Can I replace just the box if it fails?
As a rule, no. The cord set is tested and listed as one unit, and manufacturers supply the set rather than a bare box. If the box fails, contact the manufacturer about repair or replacement of the set — and do not open it.
Does a wallbox have an IC-CPD?
It has the same functions, built into the case instead of hanging on a cable: signalling, checks and protection all live inside the wall unit, which is why a wallbox has no box on its lead. The features that result are compared in wallbox home charger features explained.
Why does the box get warm?
Slight warmth under load is normal electronics behaviour. Heat you cannot keep your hand near, a hot plug, or warmth that arrives with a smell is different — stop the session and have the setup checked.
Related Reading
- Portable EV Charger Buying Guide 2026: Specs, Costs, and When to Choose One Over a Wallbox
- 7kW Portable EV Charger vs. 7kW Wallbox: Which Should You Choose?
- Can I Charge an Electric Car From a Normal Socket?
- Wallbox Home Charger Features Explained: Display, Scheduling, and Load Management
