Questions & Answers (Q&A)
Q. What is the cost to charge your EV at this station?
A. For DC fast charging the cost is $10.00/hr. and for the AC Level 2 charger the cost is $1.00/hr.
Q. How much time to charge my EV?
A. Depending on the state of charge (SOC) of the EV, it usually takes 30 minutes to fully charge using DC fast charger. Some EV’s are programmed to stop charging at 80% SOC since the remaining 20% to full charge takes a lot more time due to resistance of the EV battery. The AC level 2 charging is slower due to the capacity of the charger and the converter in the electric vehicle. The AC power of the L2 charger is converted from AC to DC in the EV. Depending on this converter (3.75kW or more) it will take several (3-6) hours to fully charge the EV.
Q. How do I start charging my car?
A. Follow the instructions on the signage at the station. First and foremost plug in your EV before authorization and activation of the charger. Activation of the DC fast charger is performed at the touchscreen of the Level 2 unit located at the front of the station. Authorization to enable charging can be by credit card, phone app, QR code, membership card or calling into the phone help line displayed at the station.
Q. How many electric vehicles can charge at one time?
A. Both DC fast charging and AC Level 2 charging can take place at the same time. Activation at the touchscreen has to be performed one after the other, by following the instructions on the screen.
Q. What is a smart grid EVcharging station?
A.This charging station is equipped with a 50kWh battery system. Most DC fast chargers with 50kW capacity take initially a maximum of 50kW from the electrical grid. However, thanks to the battery system the DC2DC™ charging is not taking more than 20kW from the electrical grid, thus avoiding costly demand charges. The remaining 30kW is delivered by the battery system. The setting of 20kW from the grid can be adjusted that no power is taken from the grid, so DC fast charging can work independent from the grid. Also, thanks to the 3-phase 480VAC connection at this Intel location, the battery system could be used for back-up power (UPS), load balancing and frequency regulation of the electric grid.
Q. What is the life expectancy of this charging station?
A.The station can be upgraded with new technology when available. The guaranteed life expectancy of the solar roof is 20 years, and the structure is expected to be beyond that time. The battery system has lithium-ion (li-ion phosphate) batteries and its life expectancy is depending on various factors, like deep discharging and number of cycles. Practically these batteries will take 5,000 cycles before loosing capacity, so a life expectancy of 4-5 years depending on visiting EVs for charging. The battery technology, battery management system (BMS) as well as the DC fast charging technology is rapidly developing with more advanced applications. We expect regular remote downloading of upgraded software on the systems for the coming years. DC fast chargers with larger capacity beyond 50kW (like the Tesla Super Charger) and battery systems with more efficiency are expected in the very near future. Once available the ETM™ station can be upgraded accordingly without jeopardizing the actual physical presence.
Q. What usage do you expect of the system?
A. Assuming an average 30 minutes DC fast charging per EV, during normal working hours from 7:00am thru 6:00pm this station could service on average 22 EV’s daily. As a good indicator, the DC fast charging station at Whole Foods Market in San Jose is presently serving some 30 charges per day (https://chargedevs.com/newswire/given-the-choice-ev-drivers-prefer-dc-fast-charging-12-to-1-over-level-2/).