electric car charging in common property car park

It’s funny you should ask that … about a year ago I wrote a document for Audi that married the needs of electric car owners and owners corporations.  As this is an area that’s bound to be growing, it’s something all large buildings should be looking at.

In very simple terms, unless you have a dedicated power source connected to your unit’s electricity supply, you need:

• a way to connect your high voltage charger to the building’s mains,
• a meter so the building’s management knows how much to charge you for using its power,
• by-laws that ensure the installation is done safely and professionally and that ensures the installation and ongoing maintenance of the supply is the responsibility of the owner.

It would benefit all strata schemes to have a policy worked out, with attendant by-laws ready to roll, as the popularity of electric cars spread.

As this article by a commercial installer explains, the high voltage wall-mounted kit supplied with most electric cars is a “dumb” unit that doesn’t measure the amount of electricity used. However, you can add your own meter which can be monitored remotely.

So it is worth approaching your committee now and asking them how they plan to respond to future requests for installation and, at the same time, provide them with information and options that may be open to them.  

One thing you can’t do is just hook your car up to a mains socket like it was a trickle battery charger. You need a professionally installed three-phase supply that is connected to the buildings power supply. For that you will need:

• Permission from the Owners Corp
• A special resolution by-law allowing you to change common property (and take responsibility for the installation)
• Safe and secure cabling from the building’s power board to your parking spot
• A secure wall-mounted supply with a sealed meter of some description.  All of this will have to be installed so that you can’t fiddle the meter and your neighbours can’t steal your power.

Good luck.

@JimmyT said:
…One thing you can’t do is just hook your car up to a mains socket like it was a trickle battery charger. You need a professionally installed three-phase supply that is connected to the buildings power supply. …

Actually a trickle charge on an ordinary socket is exactly what you do nearly always, albeit you ‘trickle’ at 10A. 

Electric vehicles happen to one of my ‘things’. I have been driving fully battery electric cars for 8 years. I converted a petrol car when buying one was not an option. About 3 1/2 years ago we got a second EV, a commercial Mitsubishi iMiEV. 

One thing people tend to assume is that a fancy fast charger is required, which then requires the 3-phase supply and so on. It might be handy occasionally but in practice virtually everyone finds that an ordinary 10A power point, or at most a 15A outlet, is sufficient. You really don’t want to be routinely charging on a fast charger anyway if you want longevity from your battery. Installing a fast charger for everyone would be prohibitively expensive and unnecessary. Having just one would be nice-to-have but it won’t be fast if it is the only way to charge so there is a queue to use it.

Far better to let everyone charge slowly when they want at their own parking spaces. This works fine if you don’t need the car full in a hurry, which you usually don’t. Far more often you need to have it full in the morning, which can easily be done on an ordinary power point. Sometimes you need to have had a useful top up for when you plan to go out again a little later, which can also be achieved with a couple of hours of ordinary power point charging. 

There is no single, best solution for retrofitting EV charging into strata titled properties. My first choice, if it is physically practical, would be to just let everyone have an ordinary 15A socket in their parking place wired back their unit/lot’s meter.

If you have a garage already, and you have an ordinary power point already, and it goes to your personal meter, you are set. You can get an ‘EVSE’ (a special charging cable with some smarts in a box in the cable) which has a bog-standard, moulded 10A plug on one end to go into an normal powerpoint. It will comply with standards that tells the charger in the car to not take charge any faster than 10A. If you have an EVSE with a 15A plug, the box in the cable will tell the car to not take more than 15A. Most cars come with an EVSE with a 15A standard plug. Often this is being conservative as the EVSE actually only takes 10A. Anyway, a 10A or 15A single phase socket is routine, standard stuff. 

It gets more complicated if you can’t simply hard-wire back to the lot/unit’s meter. Then, I would still advocate that the OC supplies a 15A outlet at each parking space with some means to sub-meter each unit’s usage. If the OC wants to also have one fast-charger as well, that would be icing on the cake. Charging a higher kWh charge for that would encourage people to only use it when they need it, which won’t be often, so it will be available for people who need their battery full rapidly. 

BTW. I could not get a power point wired back from my parking space to my townhouse unit (too far). I park adjacent to a neighbour’s unit in a shared carport. I was fortunate that my neighbour and our OC approved having an ordinary 15A socket in the carport between the neighbour’s space and mine wired back to the neighbour’s meter box. We have had meter on just that outlet and I reimburse my neighbour for what I have added to his bill, a few hundred dollars every 6 months or so. This works while he continues to pay a flat electricity tariff. It would get complicated with time of use metering and so on. 

Hi Jimmy,

I wasn’t really advocating the friendly neighbour solution for mass adoption; it is just what works for me as a stop-gap until the rest of the world catches up. If I could plug in at my unit, I could take advantage of our time of use tariff and choose to mostly charge at off-peak rates and mostly avoid peak rates except when I mean to go out again for a second longish trip soon after returning from the first. 

Installing 15A outlets for ordinary, routine, ‘slow’ charging would costs a few 100s of dollars each. Serious fast charging from a three phase supply and a billing system is well into the multiple thousands. You certainly would not put multiples of these in a strata parking area. The supply to the street probably couldn’t cope. Just one would be very nice to have though it would introduce a bunch of issues. None of those are insurmountable but given a choice, I would much rather have an ordinary power point metered back to my unit that lets me charge when and as I like on whichever tariff arrangement I care to have. As an EC member, I would much rather that too – once installed it does not have an on-going need for central administration and maintenance. If something goes wrong with the dedicated fast charger, everyone with an EV will be screaming for access to an ordinary power point. 

A big impediment to the uptake of EVs is shifting people’s thinking away from the dedicated ‘filling station’ model that they are so accustomed to from how things work with liquid fuel vehicles.  From almost a decade of experience, I can assure anyone who cares to listen that the need for fast charging is much less than is often assumed by people who don’t drive yet EVs. Most people, most of the time, will be happy with an ordinary outlet where they normally park. However, I support councils and businesses putting in charging stations here and there, even though I predict they will not get a lot of use, because it is reassuring to people who don’t yet know that they won’t need them if they buy an EV. 

So, fast charging is handy to have access to, for reassurance rather than very much actual usage. In Canberra we have had a trial running with slowish and fast chargers available for free after applying for an RFID card. Aside from trying one of the fast chargers once, just to see that it worked on the relevant inlet on my car, I have not had any reason to use it. I certainly won’t be bothering with it from now on since the local network operator, who installed the chargers, has introduced an access charge as well as a usage charge and I don’t want to pay $120/year for access to chargers that I am unlikely to need. I would much prefer a higher usage charge and free access (like a toll road or petrol station). I do buy petrol a few times a year for when I have trip out of town. I don’t have to pay an access fee to be able to fill up. 

That said, a few fast chargers scattered around a city and particularly at edges on the major routes in/out of town and at intervals on highways co-located with places selling decent coffee is what is needed to enable intercity driving. Again, the model should be free access with a charge for actual consumption. Or, you get a plug-in hybrid, which can be purely electric for most of your city driving and only use any significant amount of liquid fuel when you head out of town for a longer trip.