How to Charge a Plug-in Hybrid at Home: A PHEV Charging Guide
How do you charge your plug-in hybrid at home? We explain in plain language which hybrids plug in, how the on-board charger limits charging speed, how to calculate charging time, and how to choose the right charging solution for your electrical installation.
You've bought a plug-in hybrid, or you're thinking about it. At the dealership you were told you'd "hardly burn any petrol in town" – but that only holds true if you charge the car regularly. A plug-in hybrid that never gets plugged in is just an ordinary petrol car hauling a heavy battery around for nothing.
In this guide we explain in plain language how to charge a plug-in hybrid (PHEV) at home, which hybrids can be charged, how to work out charging time, and which charging solution makes sense for your home's electrical installation.
First things first: can every hybrid be charged?
No. The word "hybrid" is used for vehicles that work in very different ways, and that's where most of the confusion about charging comes from.
| Vehicle type | Does it plug in? | How does the battery charge? |
|---|---|---|
| Mild hybrid (MHEV) | No | Through braking and the engine; it's a small support battery |
| Full hybrid (HEV) | No | Through braking and the combustion engine, while driving |
| Plug-in hybrid (PHEV) | Yes | From a socket or a charger; partly while driving as well |
| Extended-range electric (EREV) | Yes | From a socket or a charger; the engine acts only as a generator |
| Battery electric (BEV) | Yes | By charging only |
If your car has no charging port flap, you don't need a charger. If you see a Type 2 socket under the flap, your car accepts AC charging. We cover connector types in detail in our guide to Type 2, CCS2 and CHAdeMO.
Why is charging a plug-in hybrid different?
A PHEV's battery is much smaller than a fully electric car's. That has two important consequences:
- Charging times are short. A small battery will usually fill up comfortably overnight, even on low-power home charging.
- The AC power the car accepts is usually low. In many plug-in hybrids, the on-board charger (OBC) takes in power at a lower rate than in fully electric cars. Some models only support single-phase charging.
So for a PHEV owner, the real question isn't "which charger is the most powerful?" but "how much can my car accept, and what installation do I have at home?" Whatever the charger's output, the car will never draw more than its own on-board charger allows.
How to find out how much power your car accepts
- Check the charging section of the owner's manual for "AC charging power", "on-board charger" or similar.
- The car's technical specification brochure lists the AC charging power and phase information.
- If you're not sure, ask an authorised service centre or your dealer. This value can differ between trim levels or model years of the same car.
How do you calculate charging time?
For a rough estimate, this formula is all you need:
Charging time (hours) ≈ Energy to be added (kWh) ÷ Actual charging power (kW)
Here, "actual power" means the lower of the charger's output and the power the car can accept. Real-world times will be a little longer than calculated because of warm-up, battery management and conversion losses.
As an example, imagine you want to charge a hypothetical plug-in hybrid battery with 20 kWh of usable capacity from empty:
| Actual charging power | Approximate time (excluding losses) | Comment |
|---|---|---|
| 3.5 kW | ~5.7 hours | Usually enough for an overnight charge |
| 7.4 kW | ~2.7 hours | Only possible if the car accepts this power |
| 11 kW | ~1.8 hours | Applies to the few PHEVs that support three-phase charging |
To run the numbers for your own car's battery, take a look at our guide How to Calculate EV Charging Time.
3 ways to charge a plug-in hybrid at home
1. With a portable charger from a grounded socket
This is the method plug-in hybrid owners choose most often. No installation is needed: you plug the unit into the socket and connect the Type 2 end to the car. For cars with small batteries, 3.5 kW charging is usually enough to fill the battery overnight.
For this kind of use, the WiseCar WTP1 runs at a fixed 3.5 kW. If you want both 3.5 kW and 7.4 kW options, the WiseCar WTP2 lets you switch between 3.5 kW (16A) and 7.4 kW (32A) modes at the touch of a button. Remember that the 7.4 kW mode requires a suitable circuit and socket.
Important: whichever charger you use, the socket must be grounded, and the circuit's cable cross-section and fuse must be rated for continuous load. Charging a car, which draws the same current for hours on end, is very different from short bursts of use like an iron or an oven. Before charging from an older installation, have an electrician check the circuit.
2. With a wall-mounted charger (wallbox)
If you charge your car in the same place every day, a wall-mounted unit saves you from getting the cable out of its bag every time, and because it runs on a dedicated circuit, it's a tidier solution. If your home has a single-phase supply, the WiseCar WTL 7.4 kW Single-Phase model lets you start, stop and monitor charging from a mobile app.
If your car charges at around 3.5 kW, a 7.4 kW charger won't make charging any faster; but if there's a chance you'll move to a car with a bigger battery later on, you'll already have the infrastructure in place.
3. With a flexible charger that's ready for your next car
For many drivers, a plug-in hybrid is a stepping stone on the way to going fully electric. If you're thinking about both your current car and a possible fully electric one down the line, a charger with adjustable power can make sense. The WiseCar WTP3 offers 3.5 kW, 7.4 kW, 11 kW and 22 kW power settings along with mobile app support. The higher power settings require a three-phase supply.
Which solution is right for you?
| Your situation | Sensible solution |
|---|---|
| Your car charges at low power and you charge at home overnight | 3.5 kW portable charger (WTP1) |
| Your car accepts up to 7.4 kW and you sometimes want a quicker top-up | Portable charger with selectable 3.5 / 7.4 kW (WTP2) |
| You charge in the same place every day on a single-phase supply and want app-based monitoring | WTL 7.4 kW Single-Phase wall-mounted charger |
| You're planning to switch to a fully electric car in the near future | Charger with adjustable power (WTP3) |
Tips for charging your plug-in hybrid the right way
- Plug in at every opportunity. A PHEV's savings depend on covering short daily trips on electric power. Plugging in when you get home in the evening is the easiest habit to build.
- Make use of the night tariff. A small battery fits easily into the 22:00–06:00 night band of the three-tier tariff. For details, see our night tariff guide.
- Check the car's charging timer. If scheduled charging is switched on in the car, charging may not start until the set time, even with the cable plugged in.
- Keep the cable from getting crushed. Instead of leaving the cable on the ground after charging, hang it on a charging cable holder.
- Don't use power strips or unsuitable extension leads. Using the charger with adapters or connections the manufacturer doesn't approve increases the risk of overheating.
Installation and wiring
Even if you'll be using a portable charger from a socket, the fuse, residual current protection and grounding of the circuit used for charging should be checked. Designed for 3.5 kW and 7.4 kW use on single-phase circuits, the WiseCar Fused 2+1 Combination Panel (Single-Phase) is one way to keep your charging point neat and protected. For wall-mounted installations, you can use the WiseCar Charging Station Installation Service in the provinces where it's available. All electrical work must be carried out by a qualified electrician.
Frequently Asked Questions
Can a full hybrid (HEV) be charged by plugging it in?
No. Full hybrids and mild hybrids have no charging port; their batteries charge while driving, through braking and the engine. The only hybrids you can charge from a socket are plug-in hybrids.
Will a plug-in hybrid charge faster if I use a 22 kW charger?
The car never draws more power than its own on-board charger can accept. If your car takes 3.5 kW, it will still charge at around 3.5 kW on a 22 kW charger. A high-power charger only makes sense if you plan to move to a car that accepts faster charging later on.
What happens if I never charge my plug-in hybrid?
The car will still run, carrying on with its petrol engine. But you'll be giving up most of the savings that electric driving provides.
Can a plug-in hybrid be charged at a DC fast charging station?
That depends entirely on the model. Many plug-in hybrids have only an AC (Type 2) socket. Check your owner's manual to see whether your car has a DC socket.
Can I plug a portable charger into a regular household socket?
3.5 kW portable chargers are designed to be used with grounded household sockets. Even so, because they run under continuous load, the safest approach is to have an electrician check the condition of the socket and circuit.
Conclusion
A plug-in hybrid's savings depend on regular charging. Thanks to their small batteries, most PHEVs fill up overnight on low-power home charging, so the best choice isn't the most powerful charger but the one that matches the power your car accepts and your home's installation. Start by finding your car's AC charging power in the owner's manual, then have your installation checked and choose the solution that suits you.
If you'd like help choosing the right charger for your plug-in hybrid, browse WiseCar products or get support from the WiseCar Call Centre on 444 999 1.
This content is for general information purposes only. Example charging times are calculated using a hypothetical battery capacity; actual times vary depending on the vehicle model, on-board charger, battery temperature and your electrical installation. All work on electrical installations must be carried out by a qualified electrician.
