All EV chargers deployed by ChargeLab and its partners require a reliable and consistent internet connection to communicate with the software. Network connectivity can be achieved by Cellular network (3G/4G), Wi-Fi, and Ethernet.
Cellular network
Signal strength for 3G/4G networks
- Signal reading of -80 dBm or greater is considered to be GOOD for connectivity purposes.
- Signal reading between -80 dBm and -100 dBm is considered ACCEPTABLE for connectivity purposes.
- Signal reading less than -100 dBm is considered POOR for connectivity purposes.
Mobile applications
- The signal strength of a particular location can be obtained using many mobile applications.
- The ones we recommend using for Android OS are Network Cell Info Lite and LTE Discovery.
- For iOS, the user will have to enter the field test mode on the iPhone. Open the Phone app and dial *3001#12345#*. This will route the user to the field test menu. Depending on the iOS version, the field test menu can have different interfaces1. More information can be found in the following article: iPhone Signal Strength.
- The appendix section at the end of this document provides an overview of the key parameters displayed by the mobile applications.
Pre-evaluation phase
- During the pre-install phase, a thorough walkthrough of the site should be performed to obtain signal strength readings at various locations in the parking lot/garage.
- Reach out to the site host to finalize the exact parking spaces for EV charger placement. o Walk to those parking spaces and stand at the proposed location of the EV charger. Wait for 10-15 seconds for the signal reading to stabilize.
- Open the two apps and make a note of the dBm reading. Also note the carrier and Band #, for which the signal strength is available (Rogers, T-Mobile, AT&T, etc.).
- iPhone users can enter the field test mode as described above and make a note of the rsrp0 and rsrp1 values.
- Repeat steps a, b, and c for all EV charger locations in the parking lot/garage.
- An important feature to consider when recording signal strengths is the amount of traffic present at the site. The signal strength will be impacted when more cars are parked, versus when the parking lot/garage is empty. Therefore, when performing steps a, b, and c, also make a note of the parking occupancy. If it helps, take photos of the parking spaces to capture the general feel for parking occupancy.
Network booster
- For EV charger locations that fall under the POOR category, a cellular network booster will be required.
- It is recommended to perform the signal strength test on Android OS over iOS. There are a few iPhone models with intel wireless chips that may not show rsrp0 or rsrp1 readings in the field test mode.
- After the network booster is installed, verify the signal strength readings at the proposed EV charger locations as described in Step 3. The signal strength readings at all EV charger locations should fall under the GOOD or ACCEPTABLE range.
Wi-Fi network
Signal strength for Wi-Fi networks
- Signal reading of -55 dBm or greater is considered to be GOOD for connectivity purposes.
- Signal reading between -56 dBm and -67 dBm is considered ACCEPTABLE for connectivity purposes.
- Signal reading less than -67 dBm is considered POOR for connectivity purposes.
Mobile Applications
- The signal strength of a particular location can be obtained using many mobile applications. The one we recommend using for Android OS is Network Cell Info Lite.
Pre-evaluation phase
- During the pre-install phase, a thorough walkthrough of the site should be performed to obtain signal strength readings at various locations in the parking lot/garage.
- Reach out to the site host to finalize the exact parking spaces for EV charger placement.
- Walk to those parking spaces and stand at the proposed location of the EV charger.
- Open the Network Cell Info Lite app and make a note of the dBm reading. Also, note the Wi-Fi name and frequency (2.4 GHz or 5 GHz). Most chargers are capable of functioning on 2.4GHz frequency.
- Repeat steps a, b, and c for all EV charger locations in the parking lot/garage.
Access points
- For EV charger locations that fall under the POOR category, multiple access points will be required to provide network coverage at EV charger locations. The type of access point to be installed and its positioning in the parking lot or garage will vary for each site and should be finalized in consultation with a network engineer.
New connection
- There may be sites that have no public Wi-fi as well as possess POOR cellular connectivity. Such instances will normally be found in parking garages or underground parking spaces. For such sites, a new Wi-fi connection will have to be established from the building’s telecommunication system.
- Locate the route between the telecommunication room and the proposed location of the Wi-fi modem.
- Pull a new ethernet cable and connect to the Wi-fi modem.
- Configure the modem to create a wireless local area network (WLAN) in the garage for the chargers to connect to.
- It is very important to have separate WiFi networks for EV charging and public use. The WiFi network for EV chargers should be secured to prevent any security breaches.
Firewall settings
- Oftentimes, firewall settings may also have to be updated to facilitate the EV chargers to connect to the Wi-Fi network.
- Depending on the type of site, the site host may have to reach out to the internet provider to change the firewall settings to allow Wi-fi access to the chargers, or
- The site host may have to consult the property’s IT team to make changes to the firewall settings.