Have you ever had an important call drop as you drove into an underground garage?
You're not alone. Cell signal is ubiquitous, but so are gaps in cell coverage.
As EV chargers roll out across the country, deployment teams are quickly realizing that cell signal issues can cause long delays to turn-up plans.
Many integrators are learning that advanced planning is key: to avoid issues, the best option is to survey signal as early as possible to identify potential problems.
In this guide, we cover both how to test for coverage and how to fix coverage issues if you've identified a problem.
Why Do EV Chargers Need Reliable Cellular Signal?
A stable and reliable cellular signal is crucial for many commercial EV chargers to function. Chargers rely on signal for setting schedules, creating reports, processing payments, and downloading essential software updates.
As more garages install electric vehicle supply equipment (EVSE), it's critical to ensure that these chargers can connect to their network online. A cellular repeater can be a game-changer, instantly helping almost any location receive a stable and reliable signal.
The Hidden Hurdle for EV Chargers
Most parking garages are built with concrete, steel beams, bricks, and blocks, all of which rapidly degrade cellular signal. Even open lots can face unreliable cellular signal due to nearby structures or distance from a cell tower.
As networks transition towards 5G and deploy mid- and high-band technology, users enjoy greater speed and reliability at the cost of distance. Moreover, underground garages face additional challenges due to their subterranean location.
Even higher-end garages encased in glass suffer connectivity issues, as tinted low-E glass subtracts up to 40 dB from a cell phone signal. All these factors make most parking garages cellular dead zones, thereby affecting the functioning of EV chargers.
Surveying Signal for EV Charger Projects
We've helped a number of EV charger manufacturers and installers implement cellular site survey protocols. We can even perform detailed site surveys for larger garages if necessary. If you're interested in chatting to our team about either of these, please reach out.
There are two different approaches to testing cell signal:
| Survey App | Cellular Scanner | |
|---|---|---|
| WalkTest | Wilson Pro Signal Meter COMPASS XR | |
| Capture signal metrics | ||
| Real-world speed tests | ||
| Requires SIM cards | ||
| Generate coverage maps |
The best option is to use real handsets with an app like WalkTest to measure signal levels and perform a full site survey. The benefit here is that a real device is able to run speed and latency tests to verify real-world performance.
However, a big downside is that doing so requires three phones with SIM cards for each carrier. This can be cost prohibitive in some cases.
An alternative is to use a cellular "scanner" device like the Wilson Pro Cellular Network Scanner or the Nextivity COMPASS XR.
These devices can't test real-world performance, but they can capture basic signal metrics like RSRP and RSRQ that correlate with cell signal performance.
How to Boost Cell Signal for an EV Charger
If you’ve identified a signal problem, then the next step is to find a solution.
In most cases, the simplest way to resolve issues is to deploy a signal booster or, for larger spaces, a distributed antenna system.
Signal boosters operate in three simple steps:
- An outside antenna gathers an existing cellular signal
- An amplifier strengthens and boosts the signal
- Finally, one or more inside antennas rebroadcasts the amplified signal throughout the space.
Deploying a cell booster or DAS ensures that the EV chargers can communicate seamlessly with their host servers and ready to charge EVs as needed.
Choosing the Right Booster
Navigating the world of cellular signal boosters can be daunting. Two of our favorite options for smaller EV charger deployments are the weBoost Installed | Office 200 and the Cel Fi GO X.
While these are popular devices, they’re only well-suited to smaller deployments. We strongly why we recommend reaching out for a free consultation with one of our signal experts on the right solution for your deployment:
Our team can assess your situation, answer your questions, and recommend the best solution for your EV charging station.
As CEO and cofounder of Waveform, Sina has been helping people boost their signal since 2006. He has personally tested and installed hundreds of signal boosters.
He welcomes feedback via Twitter, LinkedIn, or by email to [email protected].
