Rethinking the Design of EV Charger Configurations

Having recently come back from a 1,000km round trip, towing a trailer behind our Tesla Model 3, I’ve learned two things. Firstly, we need a denser network of reliable fast DC chargers in country Australia and secondly but equally importantly, we also need to rethink the design of electric vehicle (EV) charger configurations to allow EVs towing trailers to also be able to plug-in. We can refuel internal combustion engine (ICE) cars while towing a trailer, boat, caravan, or horse float, so why not an EV?

Plugging-in an EV while towing a trailer can lead to some creative manoeuvres under the existing reverse-park configurations

If EV demand figures are anything to go by, consumers love EVs, both around the world as well as in Australia and we also love towing our trailers, caravans, boats and even horse floats but how are we going to go combining the two? How are we going to go using our EVs for towing?

With EVs accounting for only about 8.3% of global new light car sales in 2021, there aren’t yet many two-EV households, therefore for the time being at least, when a two-car family buys an EV, it is mainly bought as a second city car, with an ICE four-wheel drive SUV or ute/truck usually the designated towing vehicle. As a result, most manufacturers have targeted their EV sales at this second car market but with EVs growing at a rapid pace, (the 8.3% global figure was a 108% increase on 2020 numbers), contrary to many projections, it may only be 3-4 years before one in every two cars sold around the world is an EV. Furthermore, with 89% of Tesla owners saying they’ll replace their car with another Tesla, many more two-EV households, such as ours, may not be that far away, which means at least one of the EVs may need to be a capable towing vehicle. To put it another way, as Tesla points out, “consumers do not buy cars that can meet most of their driving needs; they buy a car that meets all their driving needs.”

This fact is not lost on car makers several of whom have introduced impressive off-road and towing vehicles including the Rivian R1T, GMC Hummer EV, Ford F-150 Lightning, Tesla Cybertruck, Chevrolet Silverado, Toyota Hilux EV, Ram 1500, Lordstown Endurance, Bollinger B2, Fisker Ocean SUV, LDV Maxus New EV, Canoo EV Pickup and others.

Whether we’ll see any of these models in Australia anytime soon remains to be seen, however, in the absence of a national EV policy and with Australia having become a dumping ground for dirty and inefficient EVs due to a lack of vehicle and fuel emission standards, it is no surprise that car manufacturers have been slow in introducing their EV models to our shores. We’re therefore limited to only a fraction of the models available in other markets. As an example, Europe has around 120 plug-in hybrid (PHEV) and over 90 pure EV (PEV or BEV) models on the market. In contrast, with less than 30 models available in our market of which only about a dozen are fully electric, prospective Aussie EV owners are confined to about a quarter of the PHEV selection and less than a sixth of the PEV options. That said, however, with deliveries having already began in some right-hand drive markets, the arrival of the Tesla Model Y in Australia seems imminent. The Model Y should be able to tow up to 1,588kg on the 19” or 21” wheels and when the Cybetruck becomes available here, it may well become the ultimate towing vehicle with an unrivalled 6-tonne towing capability. In the meantime, the Model X is also capable of towing up to 2,300kg.

With so many towing capable EVs inevitably hitting the market, we need to ensure these cars can conveniently charge when towing. At the moment, the majority of EV chargers are mounted against a curb requiring most EVs to reverse up against the curb or some to drive-in forward. Neither method works if towing a trailer. There were technical and economic reasons why some sites were initially configured this way, but one can’t help think that many other sites were designed in this manner for no other reason other than because this is the way things have been done in the past. Five examples are pictured below.

12-stall South Lamar Boulevard Supercharger in Austin, Texas
12-stall Kemptthal Supercharger in Switzerland
6-stall Tesla Supercharger at Shanghai International Metropolis in Shanghai, China
6-stall Tesla Supercharger in Modi’in, Israel
6-stall Tesla Supercharger in Hartshead Moor, UK – Westbound

I can’t see the above configurations being any more cost effective than what I call a “drive-through” layout. A drive-through configuration as found in most petrol and gas stations doesn’t require the cars to reverse or forward park against a curb or wall but instead allows them to enter at one end and exit at the other while also allowing for EVs towing a trailer to plug-in.

Existing vs Tow Friendly Charger Configurations

As can be seen from the graphic above, in contrast to how the stalls are mostly configured now, there are numerous advantages to a ‘drive-through’ configuration. Apart from a more efficient design, a drive-through configuration makes for easier parking when towing while also giving non-towing cars a choice to either reverse-park as is the case now or forward park, particularly when two or more bays are free. If there is at least one towing vehicle being charged, the drive-through layout allows for more towing EVs as well as non-towing EVs to be charged simultaneously. As figure #2 shows, and as can be seen from the photos below, a car with even a small trailer needs to block-off four other charging bays in order to awkwardly manoeuvre into a position where an almost fully extended charging cable can reach the towing vehicle.

Tesla Model 3 towing a trailer awkwardly charging at Williams Woolshed Supercharger in Western Australia
Tesla Model 3 towing a trailer awkwardly charging at Eaton Fair Shopping Centre Supercharger in Western Australia
Eaton Fair Shopping Centre Tesla Supercharger with proposed location for future drive-through style chargers

As the photo above shows, had the Superchargers been installed at the location indicated by the red marking, the stalls could have been configured in a ‘drive-through’ formation. As the graphic illustrates, and as summarised in the table below, a drive-through configuration can accommodate the same number of non-towing EVs as the usual reverse park configuration shown in figures #1 and #2, however, while a reverse park configuration can only accommodate a maximum of one towing vehicle and two non-towing cars, a drive-through layout such as the one in figure #7, can accommodate up to four non-towing vehicles in addition to one towing vehicle.

Table comparing the simultaneous charging capacity of the three main charging stall configurations

While not as efficient as the drive-through design, a parallel park layout can still work for towing EVs. We were lucky to find one such charger in Nannup, Western Australia where we had a very convenient seamless charging experience.

Tesla Model 3 towing a trailer conveniently charging at the parallel park configured 50kW DC charger in Nannup, Western Australia

The reverse park, parallel park and the drive-through configurations constitute the three main layouts, however, these can be combined into numerous variations to suit a specific site, such as illustrated below.

Example of a charger stall configuration utilising a combination of layouts
Example of a charger stall configuration utilising a combination of parallel park and reverse park layouts at the Tesla Supercharger in Aiea, Hawaii

Naturally, one solution open to towing EVs is to unhitch the trailer, boat, caravan or horse float in a nearby parking space and to then drive the EV to the charger and plug-in as per normal. An ICE car towing a trailer doesn’t have to unhitch just to fill up with petrol or gas and an EV driver shouldn’t have to do so either, as there can be many disadvantages to this approach including the following:

  • It can be prohibitively inconvenient to unhitch a trailer,
  • it can be unnecessarily time-consuming to unhitch a trailer,
  • EVs that are towing will consume more energy resulting in a shorter range which means they’ll need to charge more often. This in itself can potentially be seen as a small inconvenience, so it doesn’t need to be further exacerbated with unnecessarily unhitching and hooking on the trailer at each charging station,
  • when a trailer is unhitched from a car and parked elsewhere it needs to be secured to prevent another car simply pulling up, attaching it to its tow bar and stealing the trailer, caravan, boat, or horse float,
  • it’s not uncommon for particularly older trailers to have no brakes requiring the wheels to be manually chocked on anything other than the most level surface which exacerbates the inconvenience of unnecessarily hitching up and unhitching a trailer,
  • the jockey wheel near the point of the A-frame of many trailers doesn’t reach low enough to attach to the towbar of some cars such as the Model 3 without an adapter, requiring a minimum of two people to hook-on or unhitch a trailer, 
  • it’s not uncommon for some trailers to have finicky electrical connections requiring extensive jiggling of the connection in order to get it to work properly, requiring at least two or three people to establish a stable working connection.

As outlined above, unhitching a trailer, boat, caravan or horse float just to charge, is unnecessarily time consuming and there are numerous impracticalities and inconveniences to this approach and as mentioned earlier, an ICE car towing a trailer doesn’t need to unhitch just to fill-up, therefore, neither should an EV.

A drive-through configuration such as that found in most petrol / gas stations is the logical solution having the following benefits:

  • It is designed to cater to electric vehicles towing a trailer, caravan, boat, horse float or anything else,
  • it is a more efficient design allowing more EVs to be charged simultaneously,
  • it is a more convenient design allowing particularly towing EVs but also non-towing EVs to get in and out of the charging bays faster and easier,
  • it doesn’t require unnecessarily fully extending the DC cable to reach the towing vehicle,
  • notwithstanding the fact that the Tesla Semi or other electric semitrailers will have their own dedicated charging networks and assuming they will have a plug that is backward compatible with CCS2 and perhaps also a Type2 (Mennekes) connection for trickle charging, a drive-through layout may be the only way these trucks will be able to charge at regular charging stations.

As noted earlier, due to economic constraints in augmenting the existing network infrastructure, and as not all sites are the same, naturally, every site won’t lend itself to a drive-through layout, however, in situations where it is possible to achieve a more logical, more efficient, user-friendly design at little or no additional cost, a better thought-out configuration such as the angled drive-through design should be considered.

Below are some examples of tow-friendly Tesla Supercharger configurations:

Tesla Supercharger in Hitra, Norway
12- stall Tesla Supercharger at Morongo Trail in Cabazon, California with dedicated charging stalls for towing EVs
16-stall Tesla Supercharger in Ystad, Sweden
10-stall Tesla Supercharger in Rudshøgda, Norway
20-stall Tesla Supercharger in Malung, Sweden
16-stall Tesla Supercharger in Fåvang, Norway

Most petrol and gas stations have a convenient drive-through design so why should EV owners have to reverse-park against a curb to plug-into an EV charger? From the perspective of an EV owner towing a trailer, the current reverse-park layout is a major oversight requiring immediate rectification.

This concludes part one of a two-part article. Part two can be found herehttps://www.tocwa.org.au/2022/04/20/major-parts-of-australia-in-desperate-need-of-reliable-fast-dc-chargers/

[This article was edited on 22nd of April 2022, to add the second (right) image of the Morongo Trail Cabazon Supercharger in California which better shows the dedicated charging stalls for towing EVs. Thank you to Steve @rexjamo for supplying this photo.]

Pete Petrovsky is an active TOCWA (Tesla Owners Club of Western Australia) committee member and a long-time EV enthusiast. He placed a $6,000 deposit for a Model X (#39) in 2014 but when it came to taking delivery he couldn’t justify the cost, so instead, he and his wife decided to buy two PHEVs and wait for the Model 3. In March of 2016 they bought the Holden Volt and a couple of weeks later the Mitsubishi Outlander PHEV, and on the day it was unveiled, Pete ordered the Model 3. After selling the Outlander, in September 2019, Pete received his long awaited first Tesla, a Model 3 Performance. Despite still loving their Volt, Pete and his wife took delivery of their second Model 3 in December 2021. In his spare time, Pete also runs the ‘Tesla Ahead of the Curve’ YouTube channel and is also a long-term Tesla shareholder.

Major Parts of Australia in Desperate Need of Reliable Fast DC Chargers

Having recently come back from a 1,000km round trip towing a trailer behind our Tesla Model 3, I’ve learned two things. Firstly, we need a denser network of reliable fast DC chargers in country Australia but importantly we also need to rethink EV charger design and configurations to allow EVs towing trailers, caravans and boats to also be able to charge. This is part two of a two-part article. I address the need for more efficiently designed EV charger configurators in part one.

With almost 70,000kms on the clock in a little over two and a half years, I drive almost twice as much as the Australian pre-Covid average of about 15,000km a year. As I can charge at home, if I exclude long road trips, I’ve never come anywhere to even close to running out of the Model 3 Performance real world city range of approximately 500km (the car is rated at 530km at the WLTP standard).   

That said, while our M3P, may have considerably more than sufficient range around town, once you add a persistent headwind, higher average speeds, bigger payload, fewer opportunities for regenerative braking, a rougher coarse road, rain, colder weather, HVAC use, not to mention a fully loaded trailer, the usually more than sufficient 450-500km range starts to take a considerable dive to closer to 250km or less. While in theory, the 250km is more than enough to still stay within the recommended no more than two-hour drive legs in between at least 15-minute rest breaks, in practice, things become a little more challenging when EV chargers are more than 250km apart or in our case, when the only DC charger along a 320km route ceases to work.

CCS2 port unavailable at Kojonup 50kW DC charger

While a large battery with increased range would obviously help on the occasional long road trips, at all other times, it would add unnecessary extra weight thereby reducing efficiency and handling while increasing the embodied energy, not to mention the price and hence the economic payback period of the car. A better solution is a denser network of reliable easy-to-use fast DC chargers particularly in country areas.

Unfortunately, the coverage of most EV charging networks in Australia is still very limited and the reliability of non-Tesla chargers is far from optimal.

With only a few hundred public DC chargers in Australia, primarily centred around the eastern states, there are vast uncovered areas in Australia compared to the full coverage in New Zealand Source: Plugshare
The USA map can only show some DC chargers. With over 65,000 public DC chargers in the USA, it is too resource intensive for the website to load all the DC chargers.
The map of Europe can only show some DC chargers. With over 25,000 public DC chargers in the EU, it is too resource intensive for the website to load all the DC chargers.

While Tesla can boast near-perfect Supercharger reliability and the largest EV charging network in the world, the fact is that we still have large gaps in many parts of country Australia, particularly in WA, NT, SA and northern and inner parts of QLD. As demand for Tesla Superchargers is only increasing around the globe, jurisdictions with lacklustre EV policies understandably rank lower on the priority list. Not only do we have no real national EV policy to speak of but with Australia becoming a dumping ground for dirty and inefficient cars, due to our lack of vehicle and fuel emission standards, it is no surprise that Australia is not a high priority.

Tesla Supercharger reliability, Source: Tesla Impact Report 2020
Map of Australian and NZ Tesla Superchargers Source: Plugshare

Australia no longer manufactures the Commodore, the Falcon or any other mass-market cars, so we have no choice but to buy what the world sells. Apart from a couple of exceptions, with virtually all manufacturers ceasing the production of fossil fuel vehicles either by 2025 or before the end of this decade, our DC charging networks will need to expand, fast.

(This was part one of a two-part article. Part two is available here: https://www.tocwa.org.au/2022/04/20/rethinking-the-design-of-ev-charger-configurations/

Pete Petrovsky is an active TOCWA (Tesla Owners Club of Western Australia) committee member and a long-time EV enthusiast. He placed a $6,000 deposit for a Model X (#39) in 2014 but when it came to taking delivery he couldn’t justify the cost, so instead, he and his wife decided to buy two PHEVs and wait for the Model 3. In March of 2016 they bought the Holden Volt and a couple of weeks later the Mitsubishi Outlander PHEV, and on the day it was unveiled, Pete ordered the Model 3. After selling the Outlander, in September 2019, Pete received his long awaited first Tesla, a Model 3 Performance. Despite still loving their Volt, Pete and his wife took delivery of their second Model 3 in December 2021. In his spare time, Pete also runs the ‘Tesla Ahead of the Curve’ YouTube channel and is also a long-term Tesla shareholder.

Dealing with Electric Vehicle Misinformation

Social media can be very challenging day after day, handy for staying in touch with distant friends and relatives but an often a battlefield of mistruths, aggravation and division.

Like many other discussion topics, a mention of Electric Vehicles brings out a vast amount of opinions for and against, you have three main choices to deal with it:

  • 1. Delete all forms of social media and live happily ever after.
  • 2. Scroll fast without reading the article or any comments.
  • 3. I highly suggest you take up one of the first 2 options but if you want to engage please read the following:

There are two main types providing negative comments against EVs, those that just don’t know any better and are just repeating information they’ve seen/heard elsewhere without fact checking and those that know full well the information they’re providing is misleading/false. The second type are generally repeat offenders as they have skin in the game so to speak.

  • Only engage if you feel it’s absolutely necessary, if someone comments “I’ll stick to my V8 thanks” leave it be.
  • Have quality Australian based articles on EVs ready to go and provide the link when necessary.
  • Keep your comments polite no matter how abusive others become.
  • Keep in mind your comment/answer is aimed at the fence sitters more than the EV naysayer.
  • Provide evidence based facts not opinion.
  • For some responses a photo is worth a thousand words.
  • Mention your “EV” rather than your Tesla, being generic keeps prevents the discussion being side-tracked.
  • Be ready for the goalposts to be moved, when they are your comment has hit its target.
  • Avoid climate change discussion, many on social media only care about themselves.
  • Discuss energy independence, fuel and servicing savings, safety, performance, convenience.

The 21st Century is a world of self interest, tell them what they want to hear.

Portable Power Packs are Wasted on Recharging EVs.

A portable power pack (also referred to as a solar generator) is sold in a variety of storage capacities from 150Wh up to and beyond 2000Wh. At this stage they are generally very expensive in terms of dollars per Wh of storage, if you purchase a unit that fits your needs and plan to use it on a regular basis it’s a useful product, otherwise they’re a waste of money and battery resources.

A big gripe I have is many of the power packs on the market are advertised as being useful for recharging an EV, no doubt the larger units can charge an EV but making this part of a purchase decision is poor thinking. Why? A fully charged larger unit could potential add 8 to 10kms of range to a Model 3, handy in absolute desperation but with a Model 3 Standard having at least 330kms of range at 110kmh no one who adheres to the ABCs of EV ownership should be getting stranded. If you think you may be 8kms short of range, slow down by 5-10kmh, you may arrive 15 minutes later than planned but that’s better than sitting on the side of a road while trickle charging from a 27kg device that costs $2000 or more.

So how is a power pack useful- As I said if you’re going to use it on a regular basis away from home they can be very convenient, despite most cars having multiple 12v power outlets they’re never always close to hand, having the flexibility of multiple phone, iPad, Laptop and Camera/Drone battery charging outlets away from the car when a 240v outlet is too far away is fast and convenient, they’re also very handy keeping a portable freezer operating away from established power.

There are two main types of power packs, the larger ones have a built in inverter and one or two 240v outlets capable of running appliances such as TVs, power drills or kettles for short periods of time, the extra internals needed add to the purchase price and the overall weight. The smaller power packs rarely have a 240v capability so are generally less cost per Wh or storage. If you can get through a few days without a 240v outlet that makes your choice easier.

Testing a portable power pack

To run the test I purchased a Coleman 40Ah power pack as this was readily available at a wide variety of camping stores throughout Australia, it currently is the best value per Wh of storage and most importantly contains LifePo4 batteries. These are heavier but are more likely to survive the expected 2000+ cycles before storage capacity is down to 80% of original. The 40Ah power pack has 512Wh of capacity and could potentially power 8 devices at once.

Test one – See how long a 100% charged battery would last while cooling a 45-litre fridge/freezer down from 18C to -15C, this was done during the day in an outside but shaded area in temperatures between 23C and 30C. The pack supplied enough power to allow the freezer and the originally room temperature water containers to reach 0C within 95 minutes, this consumed 16% of the available battery. I stopped the test after 10 hours with the battery down to 5% and the internal freezer temperature -15C. The test was run entirely during daylight hours.

Test Two – See how long a 100% charged pack would maintain the fridge freezer at -4C. This test commenced at 8.05am and continued through two full days and one night, the maximum temperature during that time was 30.6C, the overnight minimum was 21.6C. I concluded the test after 35 hours with the battery level down to 4%.

Test Three – See how much charge my old fold out 100Watt solar panel can add to the power pack without shifting the panel to follow the direction of the Sun. Considering there was early morning tree shade and a small amount of cloud cover in the late afternoon the 80% added to the battery was very handy. The Coleman 40Ah power packs inbuilt MPPT was a significant advantage. A 120W solar panel or shifting the panel once during the day would have provided a 100% charge.

Test Four – Can the solar charging keep up with a Fridge/Freezer set at -4C? Yes, the F/F requires around 65% of the battery over 24 hours, the 100W solar panels replaced 80% during daylight hours.

To summarise: portable power packs can be a handy accessory if you purchase the correct size for the planned tasks and use it on a regular basis.

Rob.