Most EV charging happens at home – so you need a good home charger. There are so many products with different features and price points. What’s worth buying?
I recently made a video explaining everything you need to know about buying a home EV charger.
If you don’t feel like watching – here’s a summary:
The basics: kilowatts (kW), kilowatt-hours (kWh), AC and DC
Power vs Energy
Power and energy are not the same. If you don’t know the difference, charging an electric car can get mighty confusing.
To keep it simple:
Power (kW): Your car’s charging speed. This can vary from 2 kW with a ‘trickle charger’ up to 22 kW with a three-phase dedicated home EV charger.
Energy (kWh): Your car’s battery capacity. For example, the cheapest Tesla Model 3 stores 57.5 kWh of energy in its battery.
As a rough rule of thumb, every kWh of battery capacity gives you five to six kilometres of range. So a trickle charger adds about ten kilometers of range to your car every hour it’s plugged in.
You use power and energy to calculate the time it would take to charge a battery at a given power rating.
For example, the Model 3’s 57.5 kWh battery, charging at 2 kW, would take 57.5/2 = 29 hours to fully charge.
AC versus DC charging
Home charging uses AC (Alternating current) power1. Public fast charging uses DC (Direct Current) charging.
AC charging is slower than DC charging because it is limited by the car’s internal AC to DC inverter.
A car advertised as having a charging speed of 150 kW DC can only charge at 7 kW AC on a single-phase home charger.
Make sure you have lots of solar
EV charging will significantly add to your home’s energy consumption.
Solar can almost entirely offset this if you have enough on the roof (and charge during the daytime).
This is why I upgraded from 6 kW to 20 kW:
Older 6 kW system facing south, new 14 kW facing north (up).
If you have an EV, it makes sense to have a roof full of solar panels.
Why do you even need a dedicated charger?
Many EVs come with a portable charger that plugs into a regular powerpoint. If your car doesn’t come with one, you can buy one for a few hundred dollars.
My electric Mini and its portable charger
These ‘trickle chargers’ can happily charge your car – slowly.
So why should you spend more on a dedicated wall charger?
Dedicated wall chargers charge three to ten times faster than trickle chargers, depending on whether your house is single-phase or three-phase and how fast your car can charge from AC power.
That allows overnight charging from flat.
Can’t you use public charging stations if you need to charge fast?
Home charging maxes out at 22 kW AC. Public fast-charging stations can go up to 350 kW DC.
That’s 350 km of range in as little as 10 minutes.
It’s not unheard of for some EV owners to trickle charge at home, and if they need to charge fast, they can go to a nearby public charger.
A bank of Tesla superchargers
But fast public chargers can cost 60 cents per kWh or more – double the price of grid electricity.
Relying on public fast-charging stations in place of a home charger is inconvenient and expensive – unless you only need to fast charge once in a blue moon.
Okay – so why not buy a cheap home charger?
While a cheap, ‘dumb’ EV charger will charge your car faster than a trickle charger, it won’t sync with your solar, battery or electricity tariff.
It’ll charge your car at full speed whenever it’s plugged in, even though electricity may be cheaper a few hours later.
This means you’ll pay way more for charging than you need to.
Pricier ‘smart’ chargers can automatically charge from cheap electricity (solar or grid), avoid expensive peak pricing periods, and avoid dumping your home battery’s energy into your EV.
What features should you look for in a ‘smart’ charger?
First and foremost: OCPP compatibility
OCPP stands for Open Charge Point Protocol. It means third-party services can control your charger.
It future-proofs your charger.
One example: Some electricity retailers may offer a cheaper EV charging tariff if they can control your charger via OCPP to avoid charging during wholesale price spikes.
Second: Untethered
Most chargers have both a tethered and untethered option. Tethered ones come with a built-in cable.
Untethered (left) and tethered (right) variants of the Delta AC MAX
As a result, they cost more, and the longest cable I’ve seen a tethered charger come with is 7.5 meters.
I bought an untethered charger and a ten-meter ‘type 2 to type 2’ cable.
It’s long enough to reach the second car in my driveway no matter which way it’s parked, and saves a lot of car shuffling.
Thanks to my 10m cable, I have no problems charging two EVs in a long driveway.
Third: Solar charging
If your car charges during the daytime, your solar system will offset its usage.
However, if your charger pulls 11 kW and your solar only produces 5 kW, the grid will provide the remaining 6 kW. This is great for fast charging but not so great for your bills.
EV chargers with smart solar charging functionality can be set to only charge your car from excess solar.
Fourth: Three-phase
Single-phase home EV chargers can charge at a maximum of 7 kW, while three-phase chargers can charge at a maximum of 22 kW.
The speed at which your car can charge on three-phase depends on the model. Current Teslas charge at 11 kW on three-phase, but BYDs can only charge at 7 kW AC—even on three-phase.
My advice: get a three-phase charger if your house has three-phase power. It’s only a few hundred bucks more, and even if your current car can’t use the extra charging speed, it future-proofs your home charging.
What will an EV charger cost you?
Good quality, dumb EV chargers can be purchased for about $800.
Funnily enough, a Tesla wall connector is a ‘dumb’ charger – but it’s reliable and low-cost (~$800). Although Tesla has told us, it will become smart soon via a software update.
Fully featured ones cost $1500+
My untethered Delta AC MAX charger (cost $2,000)
My EV charger comparison table shows specs and pricing for all major products available in Australia.
What do chargers cost to install?
This depends on the difficulty of the charger’s installation. Installation costs for a simple single-phase dumb charger right next to a spacious switchboard could be as low as $300.
Costs can climb into the thousands for more complicated installs involving long cable runs and solar/battery integration.
The typical home can expect to pay about $1000 for installation, plus the charger cost.
Home batteries should be for your home, not your EV.
To use the Tesla ecosystem as an example – the Tesla Powerwall battery can store 13.5 kWh. The cheapest Tesla Model 3 has a 57.5 kWh battery.
Home batteries are much smaller than EV batteries. Dumping all of a Powerwall into a Model 3 will only charge it by 24%, leaving you no energy to get your home through the night.
Meanwhile, the typical Aussie home uses 16-30 kWh daily (excluding EV charging).
The 13.5 kWh of Powerwall storage is far more valuable in your home, where it could power close to 100% of your overnight demand.
If your EV charger doesn’t have the smarts to avoid draining a home battery, there’s a simple wiring change your installer can make.
What are some of the best chargers on the market?
I surveyed my network of ~500 installers and asked them 1) what EV chargers they’d buy if money were no object and 2) if they were on a budget and every dollar counted.
The Fronius Wattpilot easily won the ‘money’s no object’ category. But it only makes sense if you already have a Fronius inverter.
Fronius products have a fantastic reputation.
Tesla’s Wall Connector won the ‘every dollar counts’ category.
It’s strange, but welcome to see a Tesla product win a budget category.
For brands I recommend – I’ve put together the following chart:
I’d be happy to recommend any of these brands to a friend.
Can your car power your home?
Many EVs allow you to power an appliance from the car’s charging port (known as V2L or Vehicle to Load), but to power your home (V2H, or Vehicle to Home), you need an expensive “bi-directional” charger.
The only bi-directional chargers I know of in Australia are the Wallbox Qasar ($10,000), and the Sigenergy DC EV charger (~$8,000). The only compatible electric car is the Nissan Leaf Gen 2.
This will change, but for now, V2H is rare as hen’s teeth in Australia.
A Hyundai Ioniq 5 with V2L adaptor, giving it regular powerpoint you can plug into. Image credit: Hyundai NZ.
Wrapping up
My advice:
- Get a dedicated smart home charger, and configure it for cheap charging.
- If you can charge during the day (even if only weekends), max out your roof with solar.
- Properly integrate your charger with your home battery.
If you’re looking to get quotes for an EV charger, I’ve got a network of hundreds of expert installers in Australia. Simply fill in my form for up to 3 competitive quotes for EV charging that’s integrated with your solar and battery.
Footnotes
- Although home DC chargers will soon be available – subscribe to our YouTube channel to see Adelaide’s first DC home charger install in a couple of weeks ↩
About Finn Peacock
RSS - Posts
Extremely useful, thanks Finn. As somebody without 3-phase at home, do you have a piece here somewhere about the pros and cons of considering that, in relation to solar, charging etc.?
Hi Nick,
There’s a few articles here that will help explain
https://www.solarquotes.com.au/search/?addsearch=3%20phase%20battery
https://support.solarquotes.com.au/hc/en-us/search?utf8=%E2%9C%93&query=three+phase
We installed our Zappie single phase charger 4 years ago in 2020. We are very pleased with its performance and its ability to manage solar vs grid.
We mostly charge in daytime usually 8-10% charge and occasionally 70% charge after longer trips.
A bit disappointed you did not review Zappie chargers in this very interesting article.
Hi Terry,
Finn has some history with Zappi, both with their warranty support and legal threats they made after SolarQuotes told the truth about it. I know there are happy customers using them but our experience hasn’t been stellar.
Compatibility of SolarEdge EV charger, SolarEdge Home Battery and Origin EV Power Up
In order to access the recent beta version of Origin energy EV power up product which allows me eight cents per kilowatt to charge my car, I’m having difficulties with the compatibility of this product and my EV charger and home battery from SolarEdge.
Unfortunately, I haven’t found a way to use any of the software features from SolarEdge without that interfering with when Origin decides to charge my car.
As a result my home battery is dumping into the car whenever the EV charger turns on.
I’d really appreciate any assistance to resolve this, whether that’s lobbing SolarEdge to make a fix or discussing options that may already exist.
Thank you, love your webpage.
Hi Andrew,
Talk to https://www.facebook.com/brent.heber/ and see what Solar Edge can do. These sorts of compatibilities are going to be a problem so it’s down to customers to raise them as they occur.
Or try Benjamin Cox on 0435 854 094. He’s very proactive in my experience.
Finn,
first, one disadvantage of plug in ´Granny chargers´ is they are hard on power points. I have replaced many over my 10+ years of charging the Imiev. The issue is the leads pull on the plug (as in your photo) & because they draw a constant 10A, they warm up. Eventually they melt….
Granny chargers are good for emergencies I feel. They should use the ring retained industrial plug for reliability. Only use really heavy (2.5mm sq) Extension leads, & definitely no loops! Keep Extensions under 15M, & preferably never use!
I have a fixed ZJBeny OCPP charger managed by Home Assistant Energy Management system (Open Source). Very good value charger. 6M Tethered
lead. (Untethered available).
Next year there will be DC chargers available for home use (Bi-directional)
Solar Edge have just announced one for next year. (Cost tba)
One thing is The World she is a Changing! Viva la future!
Hi Doug,
I’ve melted a few plugs & sockets myself…
https://www.solarquotes.com.au/blog/ev-charging-power-outlet/
Great article, Finn! Very informative.
My question – when do you think bi-directional chargers (and the EVs to use them) will become more readily available (and at more reasonable prices!)?
Hi Ross,
As day follows night, solar gets cheaper, and bi-directional charging is coming. We need it for network stability.
Thanks Anthony – yes, there is no doubt it IS coming……the big question is when! I already have 7.8kW solar on the roof, 3 phase power supply and Fronius inverter. I am teetering on the edge of buying more solar, home battery, EV and charger….so timing and availability will be big issues for me!
Is the 7 kW charging rate for single phase an Australian regulatory limitation (push) or is it an EV limitation (pull)?
In the US there’s a rule that any circuit must only be used to 80% of its max amperage for a prolonged period. Is there an Australian equivalent rule?
So, at 7 kW max then that suggests 7,000 / 230 = 30.43 Amps, so following the US 80% rule (not knowing if/what Australia has) would imply a 40 Amp circuit/breaker.
Any suggestions where to read up would be appreciated.
Hi Ram,
Australian electrical guidelines are similar insomuch that circuit protection should have headroom over and above the rated load, and it’s the circuit protection that dictates cable size (along with voltage drop)
Many sparkies run a rule of thumb 32a/6mm² circuit for EV charging and it’s not enough.
We recommend a 40a supply
What’s more interesting is that Schneider & Hager have guidance out that says if the switchboard is packed, with no air gaps for heat dissipation between circuit breakers, then the circuit should be rated for double the nominal load to deal with components being heat soaked. ie 63a for a 7kW charger!
Thank you.
So it sounds like an EV limit of the 7 kW for single phase AC.
Given the relatively immaterial cost for higher capacity wiring – I cannot understand why electricians don’t make a point of recommending much higher capacity not just for EV charging but also solar panel installations.
When I looked into this before adding panels to our roof there seemed to be only a slight difference in what there was to be gained from using double the diameter wiring (apart from it potentially being harder for the installer to run down through cavity walls).
The lower resistance (heat) due to the 4x capacity provided seemed to be agreed to add between 1 to 3% additional power output. The additional cost for the much higher capacity wiring vs the value from 1 to 3% additional generation provides a very short payback.
Surely it should be a selling point for a good electrician/installer?
Another factor in the decision process is that portable chargers can be claimed if you have a novated lease whereas wall chargers cannot.
This makes a good case for installing a 32A plug and purchasing a 22kW portable charger.
I have a single phase OCPP charger station and make use of solar PV charging and scheduled charging for super off-peak periods. While it can deliver ~ 7 kW, the reality is we rarely need our car to charge that quickly. We just don’t drive enough km (we drive a bit over the national annual average of km/year).
Super off-peak tariff plans are where a dumb charger can still do quite OK as a charging schedule can be managed by most car’s on board systems. No real need for a smart charger in these cases, the car is already smart enough.
Even a basic but decent quality 2.3 kW plug in charger (using an appropriate power outlet) is sufficient for most commuter needs.
Combined with the car’s own charge schedule control and super off peak tariff offering 6 hours overnight of very cheap power, that’s still able to deliver ~80 km of range. Very low cost of equipment and using the facilities you already have. Or a little bit more for 3.6 kW. For a lot of homes this will be plenty fast enough.
Unless you drive big miles each day, it takes a long time to benefit from spending the extra couple of thousands of $ just to have a faster home charger.
For those who can charge from solar PV like we can because the car is often at home during the day, well several EV tariff plans now exist which are offering free energy in the middle of the day anyway, which is even cheaper than foregone solar FIT credit.
These super off-peak/free energy plans negate the need for solar charging smarts (just ask ChargeHQ how that’s going).
2 or 3 hours free even with a low power charger can still add decent range, while solar PV is easily going to cover daytime demand from a low power charger when it’s sunny.
None of this is to say these smart higher power AC EV supply equipment are not good things, but in many cases it means are spending a lot of $ for not a lot of gain, when a perfectly adequate, cheaper and effective option already exists.
Perhaps worth adding a link to Tesla’s “Charge On Solar” post https://www.solarquotes.com.au/blog/tesla-charge-solar-mb2990/
And also mention their upcoming V2H support https://www.solarquotes.com.au/blog/tesla-confirms-key-powerwall-3-specs/
I just bought my parents a 15Ah charger as they wanted something slightly faster than the trickle charger that came with their EV, and already had a 15Ah plug, so was the perfect gift given it is a 50% improvement.
The only issue is the 5M length I bought struggles and they have a 30M motorhome 15Ah rated extension cable, this is fine to use I assume as they are rated the same?
Otherwise it just won’t reach.
I’ve read a mixture online some people swearing it is okay as long as you do the right thing and some others quoting that the manufacturer states no, but is this only to cover their hides from stupid people not using the correct spec equipment for the job?
Here is our best advice on extension cords and EV chargers:
https://support.solarquotes.com.au/hc/en-us/articles/6375984912015-Can-you-charge-an-EV-with-an-extension-cord
TLDR: if you must, get a screwed socket fitted, and an extension cord made up by a good electrician.