Single-Phase vs 3-Phase charging cables explained.
Many EV drivers plug into a public 22kW AC charger expecting rapid charging speeds, only to discover their vehicle is charging at 3.6kW or 7kW. The charger may clearly display “22kW AC,” yet the actual charging rate is far lower. In many cases, the reason is surprisingly simple:
The charging cable being used is single-phase.
This guide explains:
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The difference between single-phase and 3-phase EV charging cables
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Why your cable affects charging speed
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How to determine which cable you need
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How to achieve full charging speeds at public AC chargers
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Recommended 3-phase EV charging cables
This is an issue many EV drivers are unaware of — but understanding it can significantly reduce charging times at public AC stations.
Buy a 3-phase cable and start charging faster!
Understanding AC Charging Speeds
Public AC chargers in the UK are commonly rated at:
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7kW (single-phase)
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11kW (3-phase)
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22kW (3-phase)
However, the charger can only deliver the maximum power supported by both:
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The vehicle’s onboard charger
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The charging cable being used
Unlike DC rapid chargers (where the cable is attached to the unit), AC chargers require drivers to use their own Type 2 cables from time to time – and that cable determines the maximum charging capacity.
Buy a 3-phase cable and start charging faster!
What is a Single-Phase EV charging cable?
A single-phase Type 2 cable is typically rated at:
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16A (approximately 3.6kW)
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32A (approximately 7.4kW)
These cables are ideal for:
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Home charging
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Workplace charging
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Overnight charging
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7kW wallboxes
However, a single-phase cable cannot deliver 11kW or 22kW charging speeds, even if the public charger is capable of doing so.
This is one of the most common reasons drivers experience unexpectedly slow charging at public AC stations.
Buy a 3-phase cable and start charging faster!
What is a 3-Phase EV charging cable?
A three phase Type 2 cable allows higher AC charging speeds, including:
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11kW charging (16A 3-phase)
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22kW charging (32A 3-phase)
3-phase charging cables are particularly useful at:
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Public 11kW chargers
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Public 22kW AC fast chargers
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Destination charging sites
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Commercial EV hubs
When a vehicle supports 3-phase charging and is connected with a 3-phase cable, it can charge at the full rate advertised by the AC charger.
Buy a 3-phase cable and start charging faster!
Why your EV may be charging slowly at a 22kW charger
If a vehicle is charging at 3.6kW or 7kW at a 22kW AC charger, there are typically three possible reasons:
1. Your charging cable is Single-Phase
If the cable is single-phase, the maximum charging rate will be limited to 3.6kW or 7.4kW – regardless of the charger’s capability.
2. Your vehicle’s Onboard Charger is limited
Some EVs are limited to:
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7kW AC charging
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11kW AC charging
Even when using a 3-phase cable, the vehicle itself may cap the charging speed.
3. Load Balancing is active
Some public chargers dynamically share available power between multiple vehicles, particularly if the charger has multiple sockets being used by more than one electric vehicle.
Buy a 3-phase cable and start charging faster!
How to identify whether your charging cable is Single-Phase or 3-Phase
Check the label printed on the charging cable.
Look for markings such as:
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“1P” (single phase)
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“3P” (three phase)
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“16A 3P” (11kW capability)
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“32A 3P” (22kW capability)
If your charging cable only states 32A but does not mention 3-phase, it is likely single-phase.
Buy a 3-phase cable and start charging faster!
EV Charging Speed Comparison
| Cable Type | Maximum AC Charging Speed |
|---|---|
| 16A Single-Phase | ~3.6kW |
| 32A Single-Phase | ~7.4kW |
| 16A 3-Phase | ~11kW |
| 32A 3-Phase | ~22kW |
Two drivers connected to the same charger can experience very different charging speeds purely because of the cable being used.
Buy a 3-phase cable and start charging faster!
Recommended 3-Phase EV Charging Cables
For drivers who regularly use public 11kW or 22kW AC chargers, upgrading to a 3-phase cable can significantly improve charging times.
When choosing a cable, look for:
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Type 2 to Type 2 compatibility
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32A 3-phase rating (for full 22kW capability)
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CE certification
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IP-rated weather protection
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5–7 metre length
32A 3-Phase Type 2 to Type 2 Cable (22kW)
Buy a 3-phase cable and start charging faster!
Do you need a 3-Phase charging cable?
A 3-phase cable is recommended if:
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You regularly use public AC fast chargers
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Your vehicle supports 11kW or 22kW AC charging
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You want to reduce charging times at destination chargers
It may not be necessary if:
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You only charge at home on a 7kW wallbox
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Your vehicle is limited to 7kW AC charging
Frequently Asked Questions
Does a 3-phase cable charge faster at home?
Only if the property has a 3-phase supply and compatible wall charger. Most UK homes are single-phase.
Can a 3-phase charging cable be used on a 7kW charger?
Yes. The charger will simply deliver its maximum available output.
Why does a 22kW charger only give me 7kW?
Common reasons include:
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Single-phase cable
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Vehicle limited to 7kW AC
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Load balancing on the charger
Does cable length affect charging speed?
Not in any meaningful way, provided the cable is correctly rated.
Buy a 3-phase cable and start charging faster!
Final Thoughts
Many EV drivers assume the charging unit determines the charging speed.
In reality, both the vehicle’s onboard charger and the charging cable play a crucial role in determining how fast AC charging can occur.
Understanding the difference between single phase and 3-phase charging cables can prevent frustration and significantly reduce charging times at public AC fast chargers.