Chargers are being installed all over the country, often by non-EV drivers. Well meaning, government officials put a great deal of personal effort into installing chargers in parking lots all over the world. But some don't get used as much as they could be or should be.
Why? What's missing? Why is the system often not working well?
Often, the most basic question is missed...
How long would anyone spend at the charger bank location?
A Fast DC or Supercharger is a great option for drivers passing through or looking for a quick stop. Typically, an EV driver only spends 20-60 minutes at these fast charger banks and it is the perfect opportunity for a coffee break or quick stop at a convenience store.
However, as an overnight hotel guest, it is actually a hinderance to have to return to the car and unplug an hour later, especially when most networks will start charging EV drivers for tying up the charger after the car is fully charged. The typical dwell time at a hotel is at least 8 hours, which is a good match for a Level 2 charger such as a J1772. The 'Symbiotic Dwell Time' for the hotel guest and the J1772 charger to provide a full charge is 8 hours and the 220V Level 2 charger is thus sufficient for this type of business.
Businesses should consider 'Symbiotic Dwell Time' between the business model and their EV Car guests before installing a charger.
For new charger installs, the ideal type is chosen by considering the amount of time your guests naturally spend at your location. In general, EV drivers will be looking to get ~100-150 miles of range during a typical stop. The situation today shows us that sizing and locating chargers is not straight forwards, nor obvious. We hope that this table will help installers take pause to think about how drivers will naturally dwell at a given location.
Note - The range estimates in the table assume 300W-Hrs/Mile
Hotel businesses are of significant interest for the EVHotels App. In this situation, the best type of EV charger to install is a Level 2 with a J1772 plug. Level 2 is defined to be using 220V and up to 60A but is typically between 10A-40A. The J1772 charger is a simple box and cable and can be mounted outside on any post or wall. Its configuration is the most compatible across various electric cars including Tesla, Kia Soul EV, Nissan LEAF, and Ford Focus EV, among others. Furthermore, the power delivered by the J1772 charger is low enough not to be a significant drain on the hotel power supply (10A-40A) but is enough to provide about 100 - 200 miles of range to the guest’s car overnight. The delivered power can also be shared among multiple chargers. Another Level 2 charger option is the Tesla HPWS (High Power Wall Socket). Many hotels install Tesla- specific charger stations to cater to Tesla cars, however, this charger is not compatible with any other electric car. The J1772 charger, on the other hand, is considered ‘universal’ and is compatible with most common electric cars as well as the Tesla with an adaptor. In general, the Tesla HPWS is a great choice if you expect a larger proportion of Tesla cars.
The ideal EV charger type for hotels may be the Type 2 power level with a J1772 plug.
Of the other EV Charger types, the Level 3 high power charger is not ideal due to the expense and the unnecessarily fast charge time of approximately 1 hour. The Level 1 wall outlet charger type is the least expensive, but the slow charge rate will only provide about 30 miles of range and given a choice, guests will book a hotel with a Level 2 charger. However, the wall outlet is nice to have as a backup for long term stays or fully charged cars to use in order to free up the J1772 space for another electric car. Also, electric cars owners are generally very grateful for the use of even the wall outlets for a top up especially if they are located conveniently near the parking lot.
In general, businesses should consider their customers typical length of stay when deciding which type of EV charger to install. For more information, visit the Hotels Help section of our website.