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Electric vehicles are still a relatively small section of the total vehicle fleet, and notwithstanding some bumps along the way, it’s pretty clear that the proportion of them on the road and in our garages will become much larger of the next few years.
A new or prospective EV owner will inevitably be confronted with the challenge of how do they charge their car.
ICE vehicle owners probably haven’t worried about it much as for decades you could go to pretty much any petrol station and the forecourt would work pretty much the same way for a reasonably similar price to the one around the corner.
EV charging infrastructure is still developing, and like any maturing technology it comes with a learning curve. The different suite of plug types, charging speeds and costs, AC vs DC charging, not to mention the bewildering and dysfunctional array of apps you might use can be intimidating.
While away from home charging infrastructure is getting better, for many users the ability to charge at home is a key advantage that makes EV ownership attractive for both cost and convenience. As we move out of the early adopter phase of EV ownership I’d like us to have a better conversation about home charging .
Follow any EV forum or user group and charging questions will be prominent, and the advice you will get will be hugely varied, particularly regarding the ubiquitous ‘granny charger.’
This is the charger that probably came with your car (unless you have a recent Tesla) and will charge your car from pretty much any power point if you are prepared to wait long enough.
At the typical 8-10 amps they can maintain you will probably take 20-40 hours to charge your car. As you will no doubt be told by any EV veteran most people drive less than 50 km a day so as long as you top up your car regularly for a few hours the slow charging wont be a problem.
Plenty of users will tell you they have a great experience with just using their granny charger and it’s all they use and therefore it’s all you need. Why spend more when you don’t have to?
I would counter by saying you can exist fine drinking instant coffee, but there are so many more appealing options you should consider and who wants to settle for just getting by! Early adopters might be willing to put up with tinkering and compromise, but as we move to the mainstream we should be encouraging options that will be more suitable.
I’d like to suggest three reasons that we should be encouraging EV users who charge at home to strongly consider making investment in a hardwired AC charger rather than making do with the trickle charger that came with the car.
It’s easy to get distracted by the nonsense spread about EV and lithium battery safety but some things are true: firstly an EV stores a lot of energy and anything that stores a lot of energy can be destructive if that energy is released in an uncontrolled way so best to avoid it happening in the first place, and secondly, electrical safety isn’t a joke.
That new EV is going to be largest consumer of power in your house, and it’s safe because lots of smart people have designed it carefully and intentionally.
A charging EV is a stress test for your house and will find the week spots in old or undersized wiring, overloaded circuits and power points. A burned out power point or tripped circuit probably won’t cause you harm, but it’s not an acceptable solution for the masses.
A granny charger also makes it easier to make bad choices. Think using an extension cord or a power board or bargain charger your bought online to save a few bucks. A recent EV fire was caused by a charger using an international travel adaptor and extension cord .
It’s easy to shake our heads but most people are not electricians or electrical engineers and have limited capability to make safe electrical choices beyond ‘plug it in’ and ‘turn it on,’ so we should be designing in the safer outcome, rather than hoping that people will choose the safer option.
A hardwired charger installed according to the Australian standard by a licensed electrician is safer solution and we should be encouraging it be to be default option. It wont always be a suitable option (eg renters) but we should encourage people to keep the granny charger as the backup.
Most cars in Australia travel less than 50km per day and that granny charger could supply that easily in about 4-5 hours while you sleep. However, being able to charge faster has lots of advantages. Don’t you occasionally take longer trips so don’t you want to be able to charge quickly sometimes?
Electricity tariffs are increasingly moving to variable rates where electricity cost can be very cheap or very expensive depending on when you charge. You can get special EV only tariffs with extremely cheap, sometimes free, electricity for a few hours a day.
You want to be able to charge as much as possible when power is cheap and avoid charging when power is expensive. About 1/3 of Australian homes have solar panels on the roof and putting the excess power from them into your car is one of the best ways maximise your savings.
A lot of home AC chargers have quite a few smart features such as charging only off solar excess or timers to utilise cheaper tariffs. Most people want to use a car to get places, not have another item they need to add to the list of things in their life that needs actively managing, so a faster and more intelligent at home charger is a good thing for most people.
Not everyone buys an EV for purely environmental reasons, but it’s a consideration for lots of us. We are on a journey but the reality in Australia is that the emission intensity of our power supply varies throughout the day.
It’s much lower during the day when we have a lot of solar and wind and a lot higher at night when coal is still the dominant power source. This will change slowly, but will be the situation for the next decade or so.
Cheap power rates overnight are largely driven by coal power stations that need to remain operating, so if you are charging overnight you are doing so at time of maximum carbon emissions. If you prioritise charging during the day then you can achieve a greater reduction in your GHG impact.
I’m pragmatic here and most of us will charge when we need to fit our needs, but using a relatively fast AC home charger compared to a granny charger allows you to do more of your charging during the daytime and utilise low emissions electricity sources compared to overnight.
Summarising, as EV become mainstream it won’t just be the committed and passionate who will buy them.
For those of us who charge at home we should be encouraging the installation of faster, dedicated EV charging points at home and make that the default for most people, keeping the portable granny charger as the backup when travelling or for those who are renting or otherwise limited in what they can install.
The slightly extra upfront cost will be worth it. After all, you can get by drinking instant coffee, but do you really want to?
Andrew Whitson took the plunge into EV ownership in early 2024. When he bought his car the nearest public charger was 30 minutes drive away so having dependable home charging was a priority. He writes from the Lake Macquarie region of NSW.
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I’m waiting for a v2g capable charger, happy to charge like a granny until then.
The article ignores one simple fact..................
.............most cars spend all day parked up at work.
EVs will be no different, so either take your granny charger with you and plug in at work (where you could trickle charge for 8 hours and be fully loaded when you go home)..........
..........or preferably, start whinging to your boss about him installing solar panels on the car park canopy and providing free fast charging during the day (or you'll have to start looking around for a more thoughtful employer!).
Once V2whatever is approved you could get your free power during the day and use your car to power your home overnight.
The electricity grid will love you!
Same logic applies to workplace charging. And the fact that an EV spends less time at home strengthens the benefit of having a faster charger there.
A coffee snob and granny denigrater. Couldn't fit welfare scum or afl fans into your story?
Whoosh...
Typical lazy cliche response.
Be interesting to know what industry andrew 'works' in.
A lot of people on here just to boost their social media profile. Hardly worth it really.
Whatever happened to ren stimpy? Now there was a nutjob you could have a laugh with/at.
Your comment wasn't worth any more effort, nor are you, troll...
Some very good points. Thank you.
It would also be great to have proper EV chargers at more holiday accommodations.
I haven't bought an AC charger because I don't need one - I get ~1.6 kW using a wall socket, and that's plenty. If I were going to spend any money I'd want it be on a V2H device. In a blackout I would currently need to run a long extension lead and a power strip.
If I need a faster charge there are plenty of nearby chargers I can use, whether AC or DC. Several of them are even free.
Used a granny charger for the first few months, but ended up installing a 7kW charger and it's chalk and cheese really. Given how cheap they are now, they are well worth it, although the installation cost can exceed the EVSE cost if you don't have suitable wiring. We were lucky, the garage had its own 50A service separate from the house, so it just needed a breaker box upgrade.
If you are having a house rewired or building a new home, it makes no sense to not include provisions for an EV charger while that's being done.
Re: your last paragraph. Given your genius for maths and science, would you mind giving us your best estimate for how many households this might equate to in the next five years?
Remembering of course that less than 5% is statistically insignificant.
1 % of all households in Australia is actually a bloody lot, let alone 5% In any event statistically significant or not, the advice is perfectly valid.
We just bought a new EV. We will not be installing a wall box. Our portable charger can provide all the power we need, charging maybe once or twice a week. It helps that we have a small car (Fiat 500e) with a 42KWh battery.
The electricity from our “granny” charger tastes just the same as your fancy wall box. So the instant coffee comparison is a bit odd.
Also, as retirees, we will be trying to charge from our solar panels during the day and, guess what, 3.6kw from our 15 amp outlet is within the capacity of our panels. The 7kw from the wall box is not.
in short, for many people, portable chargers are perfectly suitable. They are not just a stop gap and I wish people would stop insisting that the cost of installing a wall box is an essential part of any EV purchase.
Hi Bruce, I am interested in your 15 amp plug and the power it gives. My 10 amp outlet connected to my MG ZS EV only adds 1.4 kW, when I was expecting 2.4 kW.
Are you getting the theoretical maximum of 3.6 kW? I reckon that would be sufficient for my charging needs but if it turned out to be only 15/10 times my actual 1.4 kW ( 2.1 kW) I'd probably want something better.
I look forward to hearing about your experience with this aspect
“I’d like to suggest three reasons that we should be encouraging EV users who charge at home to strongly consider making investment in a hardwired AC charger rather than making do with the trickle charger that came with the car.”
Or, you could believe in freedom of choice, and let the owner of the car decide what they need, as opposed to what you think they need.
Slow AC charging overnight is fine for the majority of drivers. If over time they decide they need more than that, then they’ll invest in a hardwired EVSE. It’s pretty arrogant to imply EV owners don’t know what they are doing, or that they are making wrong choices.
We have 2 EVs. The “granny charger” works just fine on one of them, there’s never been a need for anything faster.
I have a dedicated EVSE for the Tesla, but it came with the car, so I figured I might as well get it installed. The number of times I have used its ability to charge at 11 kW in 5 years? A grand total of twice!
(and I don’t drink coffee… 😄)
What a ridiculous OTT response. How did you possibly take the view that this will lead to less "freedom of choice"?
You may know everything but many are on a learning curve and will simply be in a better position to make their own decision after reading this.
“How did you possibly take the view that this will lead to less “freedom of choice”?
I didn’t. Where did I use the world “less”?
The author’s wording was clear… “we should be encouraging EV users who charge at home to strongly consider making investment in a hardwired AC charger”
That’s not saying “here’s the pros and cons of having a hardwired charger at home - make up your own mind”. I read it as EV owners should be pushed in a specific direction even if they would be completely OK with the slow AC charger that came with the car.
Based on other comments here, it looks like I’m not the only one who thought this article was a little “OTT” in pushing the wallbox solution.
I read ‘encouraged’ in the plain English sense of the word, not the Orwellian one…
I don't disagree with most of the above and I tell people that it is really nice having 7kW (32A) charging. What I do emphasise though is that people don't need to panic about sorting out anything more than an ordinary 10A socket before they get their car if they have a power point that they could use at first to get them started.
Once they have their car, the power point will be enough until they work out what they really need. Do they want a fancy wall unit with wireless monitoring, data logging and solar integration or is a basic unit enough? Most people will have no need to rush into a decision.
I also point out that 10A charging, about 2.3kW, by chance will give many people a pretty good approximate match to the actual solar output of a 4-6kW PV system through much of the day. That pretty good match might be good enough and close enough or they might want to be exact and get something fancy.
makes a lot of sense, I was going to manage on your "granny" charger, but given that peak power is generated at home during the afternoon it sounds a better and safer option to use it whilst its available, and stack the electrons in. Yes I am convinced.
Some good points in that article and thanks for the contribution Andrew. A lot to think about. Like many things, there are several variables that differ from one user to the next e.g. the observation that many people work away from home and can't charge during the day
In our case trickle charging from a 10A plug is the best fit for us.The EV is driven to work (50km round trip). Parking at work only available on the street.
So we charge at night from a home battery (18kWh usable storage). I'd say that the battery is 100% full at the end of each day for maybe 90% of the year. Maybe more. Even if it's a really cloudy day it might be 30% full by the end of the day.
Anyway, what I'm getting around to in a long winded fashion (sorry about that), is that our battery can discharge at a maximum rate of 5kW. If we were to install a fast charger that might draw 7kW, then our battery couldn't meet that demand alone, and we'd be drawing at least 2kW from the grid again (but more than that because of the other loads in the home).
So trickle charging works best for our particular situation. The trickle charger we have draws 8 amps which equates to about 1.9kW. The battery supplies up to 5kW at any given instant, so you can the microwave on (1kW), kettle (2.2kW) and charge the car and draw nothing (or close to nothing) from the grid.
I understand that the Tesla Powerwall 3 battery can discharge at a rate of 10kW. So if anyone has one of them, or another battery of similar capability, then this advice is less applicable.
Good point about considering fire safety re electrical. Trickle charging the car draws less than boiling the kettle, but we're conscious that the kettle goes for 2 minutes and the car can be charging for 5 hours...
I tell you what is quite charged, the emotion in some of the comments. But it's all good discussion, and good to hear other peoples viewpoints :)
I agree Michael, and extra points for not using the sexist, ageist term "granny charger"