Home > Charging a Tesla with a Fast Charger

Synopsis: The Tesla vehicles require a CHAdeMO adapter to be able to connect to a DC Fast Charger. The adapter requires a small investment but it allows owners to avail of the benefits of these stations, especially rapid charging.

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One of the great advantages of a Tesla electric car is it’s driving range.  Depending on the vehicle model, you’ll have anywhere from 245 to over 400 miles of range.

This impressive range offers owners with a peace-of-mind and practically eliminates range anxiety. Hawaii Telsa owners typically don’t have to use public charging stations – the daily ‘top-off’ in the garage generally keeps the battery charged sufficiently for regular use.

However, the use of a public charging station is inevitable. A long commute day across the island with a fully-loaded car can easily use a significant amount of a Tesla’s battery charge and make the return commute impossible unless the car is charged. Compounding the challenge is the island’s terrain – a commute from Kailua-Kona to Hilo over Saddle Road (Route 200) requires a drive from sea level to over 6,600 feet. This climb requires quite a bit of energy. The positive thing is that the drive from the summit to Hilo allows for incredible power regeneration – the car’s battery is actually recharging during the descent.

There are a number of Level 2 charging stations across the island. Many offer the opportunity to charge while the car owner is shopping or dining. However, they are slow – one can spend hours at Costco to get enough charge to make it back to Hilo.

An alternative to the Level 2 charging station is the DC Fast (“Level 3”) Charger. A typical Level 2 station offers an output of around 7kW while a DC Fast Charger offers around 50kW! This translates into much shorter charging times.

How Fast is a Fast Charger?

We recently tested the DC Fast Charger at the HECO site in Hilo. We charged our Tesla Model X 90D. We started out at 8% capacity. The car registered the following; 40kW output, 350v, 114A. After 30 minutes, the car reached 32% (20.85kWh, ~65-mile range increase). It took 102 minutes to reach 90% and a total gain of 70kWh. The following images illustrate the charge progression.

Note that to protect the battery, there is a tapering of the charging output after the battery reaches 50%. It apparently slows down quite a bit after 80%. In general, you should only have to charge to 70 or 80% and not have to linger this long at a DC Fast Charger. Tip: Remember you can enjoy the air-conditioned comfort of your EV while you charge. You can also visit nearby shops – at the Hilo site, there are a number of restaurants nearby.

Big Island Fast Chargers

There are several DC Fast Chargers on the island, and there are more on the way. These are all accessible through Shell Recharge – you can pay prior to use by calling the number listed on the charging station itself. For the best experience, create an account at Shell Recharge and download the mobile app.  You can link your account to a payment method and prepay ($20 is an adequate amount). Prepaying and having the mobile app greatly speeds up the charging process – you just have to scan the QR code on the station to start the process.

Here are the current Fast Chargers (all open 24/7, except the Punalu’u Bake Shop).

It is recommended that you check the status of a station before visiting. You can easily do this through the Shell Recharge mobile app – it will indicate if the station is “Available” or “Offline”. You can also visit plugshare.com. (If you don’t already have the plugshare mobile app, get it. It provides visibility to all commercial and private stations across the island.)

Tesla CHAdeMO Adapter

Hawaii Island DC Fast Chargers have 2 ports: CHAdeMO and CCS.  Teslas require a CHAdeMO adapter in order to use the charger. This is NOT provided by Tesla (the adapter that you’ll find in your portable charger kit is for J1772 plugs that you’ll find at Level 2 charging stations). The Tesla CHAdeMO adapter is a large device (about 24” in length). The Fast Charger CHAdeMO plugs into this adapter, and the adapter plugs into the car. Here’s what the setup looks like with the Fast Charger CHAdeMo plug attached.

Here it is, plugged into a Model S.

Tesla’s CHAdeMO adapter manual provides detailed instruction on how it operates. TIP: Based on our experience, it’s best to first plug the adapter into the car, before connecting the charger plug. The Fast Charger plug and cable are fairly large so it is easier to manage if you plug the CHAdeMO adapter into the car first.

Buying a Tesla CHAdeMO Adapter

The adapter sometimes available at the Tesla Online Store (add tax and about $50 shipping). Note: They have often been on backorder and don’t always appear on the website.

The adapter might also be available at the Tesla Store in Oahu – drop in if you’re in town to save on shipping (call to confirm availability at (808-828-3743).

You can also find them (new and used) on eBay.com. Expect a price premium as they are in high demand. Look for the “North America” version.

Fast Charging and Battery Degradation

An important consideration is the impact that fast charging might have on an electric car’s battery life. The concern (or perception) is that the use of Fast Chargers will escalate battery degradation. Since heat has a detrimental impact on batteries and fast charging can generate heat, this is an understandable concern. However, this is likely only a concern for older electric cars with inadequate thermal management.  The premature battery degradation that was seen in first-generation Nissan LEAFs in the southwest exemplifies the impact of inadequate heat management.

Various sources do cite an electric car’s battery thermal management as being critical to minimizing the impact of fast charging. Fortunately, most electric cars, including Teslas have active cooling and are able to withstand the rigor of fast charging. Note that Tesla Superchargers have a 120kW output (soon-to-be ramped to 150kW). This is more than double the output of the DC Fast Chargers on our island.

What About Other EVs???

Of course, the DC Fast Charger can be used by other electric cars, provided they are fast charger-enabled. (The fast charging capability is an optional feature in some electric cars.) If you are in the market for an electric car, we recommend that you figure out if fast charging will meet your needs and purchase accordingly.

  • Examples of EVs that have the CHAdeMO port: Nissan LEAF, Mitsubishi i-MiEV, and Kia Soul EV.
  • The following are examples of EVs that have the CCS port: BMW i3, Chevy Bolt, Chevy Spark, Volkswagen e-Golf, and Kia EV6

How Much Does It Cost To Charge?

The Fast Charger rates start at around 51 cents/kWh (they vary by time of day). At this rate, the cost is similar to or less than the cost to fill a comparably sized gas car. Importantly, the convenience of the quick charging speed (and not having to endure a long wait) makes up for the cost.

The bottom line – DC Fast Chargers can greatly improve your overall experience with your electric car. Why wait for hours at a Level 2 charger when you can be on your way after 30 minutes?!