If you’re looking to install multiple charging stations, you may have heard the terms “local load management” (LLM) or “charge management system.” While owners of single-occupant homes may look into electric vehicle (EV) load or charge management systems if they have multiple EVs, it is especially important for commercial and multi-unit dwellings to understand load-sharing EV chargers, whether they currently have multiple charging stations or are planning to expand in the future.
What is Load Management?
Load management refers to balancing how much electricity is used at any one time to manage and keep electrical loads under infrastructure capacity.
At a commercial property, there will be times when more power is needed and used, whether that’s because offices are full of workers using electricity, guests using blow dryers and lights at a hotel, or cooks using ovens and stovetops at restaurants. However, load management is available which is done through a network to maintain service and stability. When adding EV charging to your property, controlling the load EV charging stations demand so they remain below the threshold that’s required is key.
What is a Load Management System for EV Charging?
Load management allows you to control how much electricity each charging station can use when multiple electric vehicle supply equipment (EVSE) units are connected to the same circuit. Once set, the chargers will automatically use your chosen protocol to balance how much electricity each can use at a time.
Depending on your installation requirements and budget, load management may work, otherwise local load management can also be utilized. Overall, local load management works the same as load management, with the exception of it being performed onsite via hardware without the need for networked charger management. This is significant, as local load management can eliminate recurring costs.
When you use an electronic device, such as an EV charger, you expect it to have enough power to work. However, there isn’t an infinite amount of electricity available in your building. There are layers of checks and balances within an electrical system ensuring your devices continue to receive power from the electricity that is available. But an electric vehicle charging system takes much more electricity than, say, a toaster. Although your electrical panel can handle and supply energy to one charger, things become trickier when multiple are used. That’s where local load or charge management systems come in.
Local load management allows you to use your building’s existing electrical panel to charge multiple electric vehicles via charging stations by allowing the stations to talk to each other, doling out a steady electrical current to each.
Say your electrical panel provides 80 amps, but you have four chargers that each need 40 amps at full charging capacity. If each charging station worked at full capacity at the same time, they would demand more electricity than the panel can provide, causing issues and overwhelming the electrical panel. But when the chargers are able to communicate with each other, electricity can be spread out amongst all four charging stations. They won’t call for more electricity than is available.
What is Dynamic Load Management in EV Charging?
You may have also heard the term dynamic load management, which is the same as load management. Both terms are a concept utilities follow to keep their electrical load below their infrastructure’s capacity. With regard to EV charging, software-based solutions can be used to automate charge management. For example, when a second EV is plugged into an EV charger, automatic changes are made to address the amount of electricity used through load sharing.
Ways Electric Vehicle Load Management Can Provide Electricity
There are two ways in which load-sharing EV chargers will provide a steady stream of electricity to the stations via local load management: with EvoCharge stations this is through equally distributed or first in, first charged.
With equally distributed load sharing, EV chargers will get the same amount of electricity depending on how many amps are available and how many stations are being used. Using the example of the electrical panel that provides 80 amps and four 40-amp chargers, each charger will distribute 20 amps, providing an even load between the four. If one were to leave, each would begin distributing 26 amps.
With first in, first charged load sharing, distribution of electricity to the EV chargers would depend on when charging began. The first of the four charging stations would charge its electric vehicle at full capacity while the second vehicle would get as much electricity as it could with what was still available. If both vehicles are charging at full capacity with electricity to spare, that spare electricity would charge the third vehicle. Once the first vehicle leaves, the electrical load it was using would move to the third vehicle and any spare electricity would begin to charge the fourth vehicle.
Deciding on which type of load sharing you would utilize depends on how you want the chargers to be used by EVs and where they are located. A fleet manager may want to charge all of their vehicles at once over a longer period of time, so they would choose equal distribution. Meanwhile, an apartment manager would want tenants to finish charging quicker and move their vehicle out of the way so more EVs can be charged, thereby choosing first in, first charged.
Are EV Chargers Considered Continuous Loads?
This would depend on where and how the chargers are being used. A continuous load is one that is used for three hours or more at a time. Think refrigerator versus a blow dryer. At a single- or multi-unit home or hotel where EVs will be charging overnight, or offices where employees may plug-in for a half or full day of work, the EVSE will be a continuous load as it’s working for more than three hours. At restaurants or shops where it’s uncommon for people to charge for more than a couple of hours, it wouldn’t be.
To determine whether your EVSEs will be continuous load — therefore needing more electrical clearance — we recommend hiring a certified electrician who can help determine the best way to program your EVSE. Our iEVSE Plus units also come with settings that allow you to limit who can use the charger and for how long if you’re concerned about people charging for multiple hours.
Do I Need Load Management for My EV Charger?
Whether you need load management for your EV chargers depends on how they’re going to be used. For single and multi-use homes that only need one or two EVSEs, local load management may not be needed as the circuit breaker can likely handle the output. However, if you’re looking for multiple EVSEs to install on a commercial property, and you know they’ll be in frequent use, it’s recommended as the utilization of multiple chargers at once can be taxing on the system.
If your current commercial use is more lax with one or two used at a time, you may not need local load management currently, but buying EVSEs that have this capability when you notice an influx of use will future proof your charging installation. EvoCharge’s iEVSE Plus not only has all the functionality a commercial property will currently need, but can be set to balance the load sharing of up to 20 EV charging units simultaneously.
How Do Evocharge’s EV Chargers Need to Be Wired to Use Load Sharing?
EvoCharge’s iEVSE Plus charging stations need to be hardwired to a single electrical breaker. A certified electrician can hardwire two stations to the same electrical breaker, but the stations would need to use EV charging load management to ensure they don’t overwhelm the breaker.
How Do EvoCharge’s EV Chargers Communicate Load Sharing?
EvoCharge EV charging stations can communicate with each other via either Wi-Fi or Open Charge Point Protocol (OCPP) network services. Both the EvoCharge iEVSE and iEVSE Plus stations are capable of load management through both their Wi-Fi or OCPP capabilities. While other charging stations may only provide EV charging load management through OCPP and a network subscription, EvoCharge’s iEVSE and iEVSE Plus can communicate with each other directly through Wi-Fi as well, potentially eliminating the need for yearly network subscriptions for each unit connected.
Why You Would Want EV Charging Load Management?
There are many advantages of EV charging load management.
First, EV charging load management capabilities allow you to connect multiple charging stations to a single circuit which helps you avoid expensive installation costs or upgrades. With other stations that don’t provide local load management, you may need to install additional power sources or increase the amperage available to your electrical panel. This process is tedious and costly as it involves digging ditches, laying new wiring, adding to or updating the electrical panel, etc., which can run between $2,000 and $10,000 per incident. Being able to utilize what is already available saves you time and money.
Second, electric vehicle load management can help you set up your chargers to provide specific amounts of electricity during peak and off-peak hours. Whenever you use electricity during peak hours — typically 8 a.m. to 10 p.m. on weekdays — your utility company is more likely to charge a higher rate than the electricity used during off-peak hours — 10 p.m. to 8 a.m. on weekdays and all day Saturday and Sunday. Electric vehicle load management systems give you an added layer of control over how and when the stations are used, maximizing savings.
Whether you’re planning on adding multiple charging stations to your property immediately or sometime in the future, investing in load-sharing EV chargers up-front will help save you time, money and effort down the line. EvoCharge has two load-sharing EV charging stations for commercial use: the iEVSE and iEVSE Plus.