Charging on the Road

Charging when you are traveling can be a bit more complicated as there are a few more more things to keep in mind, but, again, with a couple of road trips under your belt, this will become second nature. This post will cover various types of public chargers available, how to find them and how to pay for them.

Math (ugh)

So, you have to so a bit off math sometimes when using public chargers.  At the end of the day, what you really want to know is how fast will this charger add miles back into my car.  The proper way to rate a charger is the the number of kilowatts (kW) it delivers. If you then take that number and multiply it by 3, voila, you have a best-case approximation on how many miles of range you will add per hour. Unfortunately, not every location provides kW ratings, so… math.  For Level 2 charger, sometimes, the info for a charger will only tell you the number of amps the charger handles. If you take the number of amps and multiply by 240 and then divide that by 1,000, you will know have kW.

Finding Chargers

You have four resources for finding chargers when you travel:

The Tesla website: head on over to the “Find Us” page and you can find an interactive map that will show you both Supercharger and Destination charger locations. Clicking on a charger location will reveal details on exact location, types and numbers of chargers, and any amenities.

Plugshare.com: this is a crowdsourced website of EV charger locations.  You can filter results to find a particular type of charger and clicking on a pin will bring up exact location, types and numbers of chargers, access restrictions and comments on that location.  If you access Plugshare via the in-car browser, the website will present a version of the site optimized for the car’s browser (unfortunately, its still slow).

Sites for Charging Networks: the websites for any charging network you belong to will list chargers, but, typically, only for chargers in their network–there is more on charing networks later In this post.

RV/Campground websites: this is an insider’s secret.  RVs use the same NEMA 14-50 50A hookup that you can use to charge your car.  Contact the campground directly and let them know what you want to do.  If you only need to stop for a few hours to charge, they will ofter give you a discount rate, or if you want to spend the nite, some locations often have cabins you can rent.

Types of Chargers

Basically, we categorize chargers by their charging speed and the standards they use.

Level 1 Charging

This is essentially charging from a standard 110V outlet.  Since it only adds range at a rate of about 3 miles an hour, its seldom useful while traveling.  Pretty much the only time you will use this is to trickle charge once you reach your destination or if you are stuck.  Your car’s Universal Mobile Connecter comes with an adapter that allows you to use 110V outlets.

Please ask before you plug in.  Yes, 110V plugs are pretty ubiquitous, but someone, somewhere is paying for that electricity, so ask ahead of time to avoid any issues–some folks tend to freak out when they see a car plugged into an outlet they are paying for.

Level 2 Charging

Most public EV chargers are Level 2 chargers.  Level 2 charging is based on 240V, so it tends to be faster.  Generally public stations will deliver between 6kW and 19 kW of power which translates to somewhere between 18 and 50 miles of range added per hour, but, in reality, most L2 chargers are of the 6kW variety. While faster than L1, L2 charging is still not great for road trips unless you have lots of time on your hands and have long stops already planned.  It is useful at your destination as it should be able to charge your car overnight.

All L2 stations use the same plug standard called J1772 and looks something like this:

sae-j1772c

The handle designs will vary but the plug itself is standardized.  Your Tesla comes with an adaptor that allows you to plug a J1772 connector into your charge port:

J1773_1024x1024.jpg

Using the adaptor is straightforward: plug the L2 charging handle into the wider end of the adaptor and then plug the whole thing into the car (remember you will have to manually open the charge port door).  When unplugging, as soon as you press the trigger or button on the L2 charing handle, charging stops and the car releases the handle. Perhaps the only trick to remember is that, as you unplug, use one hand to grasp the adaptor and the other hand to grip the L2 charger handle, so you pull them both out at the same time, otherwise the adaptor stays plugged into the car–it does not do any harm, but its a pain to try and pull out by itself.

Tesla Destination Charging

The Destination Charger program is a program where Tesla will provide free High Power Wall Connector to certain types of businesses (hotels, restaurants, sports venues).  The business pays for the electricity and sets the rules for access–typically they want you to patronize business in some manner and there maybe be a cost involved. The program uses HPWCs and charging speeds will vary by location.  You can find destination chargers by going to the “Find Us” page on the Tesla website.  Clicking on a Destination Charger pin will typically reveal info on charging speed and rules for access.

On-Board Chargers

Your Tesla has its chargers on-board.  Whether you can take advantage of the fastest L2 speed or not will depend on what charging equipment you have.

  • Model X and the “refreshed” Model S come standard with a 48A (11.5kW) charger and have an option for a 72A (17.3kW) charger
  • Older Model S came standard with a 40A (10kW) charger with an option for a second charger to enable 80A (20kW) charging.

If you are not sure what on-board charger you have, a quick call to your Service Advisor should answer your questions.

Level 3: DC Fast Charging (DCFC)

The next step up is DC Fast Charging (DCFC), which is sometimes referred to as Level 3.  With DCFC, we start to get into charing speeds that make long-distance travel feasible.  There are currently three DC FC standards, of which Tesla owners can take advantage of two.

Note: DCFC bypasses your on-board chargers, so it does not make any difference if you have standard or upgraded on-board chargers.

Tesla Superchargers

We’ll start with Tesla’s own Supercharger network because that is the fastest and easiest way to charge. Any Tesla owner can take advantage of the network of Superchargers as long as they have enabled Supercharging for their car.  Currently, Superchargers have a maximum charging speed of 150kW with faster speeds expected in the future.

Its important to understand how a Supercharger charges.  Basically, Superchargers have a built-in taper, so as the battery gets fuller, it charges more slowly.  The reason for this is to protect the life of the battery pack.  The emptier your battery is, the faster it will charge and, as the battery fills, the charging speed slows.

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Source:Tesla.com

This has important implications when you are traveling, since it takes less time to fill your battery to 50% twice than it does to fill it once to 100%.  I’ll cover road trips in another chapter, but, there short version is its generally a more effective use of time to charge just enough to get to your next charging stop.  Its seldom effective to charge to 90%+ unless you are stopping for other reasons, such as a meal.  Given the spacing of Superchargers, I seldom Supercharge more than 60% unless there is an uphill climb involved.

Pairing

Superchargers are paired, which means two chargers share common equipment.  If you look closely one the Supercharger pedestals, you will see them labeled 1A, 1B, 2A, etc.  Two chargers that have the same number (i.e. 1A and 1B) share equipment and the charging capacity is shared across those two chargers.  Whomever plugs in first gets the lions share of the charging capacity and whomever plugs in second gets the remaining capacity. So, when you approach a Supercharger, if you have an option, pick a charger that has both the A and B chargers unused to get maximum charging speed. Tesla complicates this a bit by not having a consistent charger layout.  Sometimes the paired chargers are next to each other (i.e. 1A, 1B, 2A, 2B…), sometimes the letters are grouped (i.e. 1A, 2A, 3A…1B, 2B, 3B…) and sometimes its totally random.

Things That Can Effect Charging Speed

  • You are on a paired charger (see above)
  • You battery is already more than 50% full
  • Your battery pack is either too hot or too cold.  This often happens when its cold and you have just started driving, but can also happen when its hot outside.  As the battery management system gets the battery pack back into its happy temperature range, charging speed will pick up
  • Its hot outside and its a busy Supercharger. I have found charging speeds can be reduced, probably because the charging equipment is in continual use.

Etiquette

Superchargers are a shared resource, so a little consideration goes along way to ensuring a positive ownership experience for everyone

  • If there is a line, don’t charge any more than you need to
  • Move your car once you are done charging–charing stalls are not parking spots
  • Pick up your trash
  • Using the Sueprcharger as you only charger will earn you the wrath of Tesla

CHAdeMO

CHAdeMO is a DCFC standard developed by a number of Japanese companies. It offers charging speed of up to 62.5kW, but as with L2 charing, the actual charing rate will vary by location. The standard uses a connector that looks something like this:

Chademo_Stecker

So, obviously, this does not fit into your charging port.  To use a CHAdeMO charger, you need an adaptor from Tesla:

The adaptor allows you to charge at up to 50kW.  The adaptor itself costs $450 with the caveat that you already have Supercharging enabled on your car (only relevant to older cars.  There is a “bundle” price to purchase the adaptor and enable Supercharging for $1,900 (prices are always subject to change, so check Tesla.com for the latest).

Using a CHAdeMo chargers will really make you appreciate the effort Tesla engineers put into the design of the Tesla charger.  The CHAdeMO charger handle is bulky as is and the Tesla adaptor only makes it worse–the process is far from elegant. I find its better to connect the CHAdeMo plug to the adaptor then plug the adaptor into the car–this prevents the adaptor from hitting the rear quarter panel.

Do you need this adaptor?  It really depends on if there are CHAdeMO chargers in the areas you plan to travel.  The best way to determine this is to go to plugshare.com and set the filter for CHAdeMO DCFC.  Certainly, its nice to have access to the additional charges but you need to determine for yourself that is worth $450. One additional caution: many CHAdeMO adaptors are at Nissan dealerships and rules for access are not consistent (some deals will be happy to let you charge, others limit access to Nissans) and often they are behind locked gates after business hours, so, if you want to plan to use a dealer-based charger, call head to find out what their business hours are and to make sure they are OK with you charging.

Combined Charging System (CCS)

CCS is an evolution of the J1772 L2 standard and is currently capable of about 100kW with work underway to support 350kW in the future. CCS uses an adaptor that looks like this, lovingly referred to as the frankenplug:

Combo_2_Connector__mid

Currently, Teslas cannot use the CCS network. However, Tesla has joined the organization that controls the CCS standard so there may be some development on that front in the future.

Charging Networks

There are companies like ChargePoint, EVgo, and Blink that are building out networks of public charging stations much the same way oil companies build out networks of gas stations.  The charging stations are typically L2 stations with a growing mix of DC fast charging stations.  Pricing can vary widely from network to network and, for some networks, from charger to charger, so make sure you pay attention when you plug in.  Typically, these networks offer two payment options: 1) a pay-as-you-go plan where you pay for electricity as you use it, and 2) a subscription plan where you prepay for a certain amount electricity at a lower rate. Its is useful to consider joining the networks that are prevalent where you live and where you travel as a backup or to augment the Tesla Superchargers and Destination chargers. You need to enroll ahead of time with these networks so plan ahead. I suggest staring with the pay-as-you-go plans and then upgrading to one of the prepay plans if you have consistent level of usage.

Charging at Work

The one more thing to check out is what the charging options are at your work.  Many workplaces offer free or subsidized charging for their employees.  If there is no charging available, it doesn’t hurt to ask if your employer is willing to install EV chargers.  Beyond the “green” benefits, there are often associated tax benefits for them.

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