UPS integration is the design and connection of an Uninterruptible Power Supply (UPS) into an EV charging site’s electrical and control architecture to provide short-term backup power during mains interruptions or voltage dips. The UPS typically powers critical subsystems (communications, controllers, payment terminals, networking, and monitoring), and in some designs it can also support controlled shutdown sequences for chargers and site equipment.
UPS integration is primarily about maintaining availability, preventing data loss, and improving resilience—not providing long-duration charging during an outage.
Why UPS Integration Matters in EV Charging
Power disturbances can cause charger downtime, failed sessions, and support tickets. UPS integration can help:
– Maintain backend connectivity so chargers remain visible and manageable
– Prevent corrupted logs or incomplete billing/session records during outages
– Keep payment and authorization systems online during brief interruptions
– Support graceful stop/restart behavior and reduce “stuck” fault states
– Improve uptime KPIs for high-availability sites (hubs, fleet depots, critical locations)
– Reduce remote recovery effort and field visits after power events
For sites with strict SLA requirements, a UPS can be part of the resilience strategy.
What Is Typically Backed Up by a UPS
In EV charging deployments, UPS backup usually focuses on low-power critical loads:
– Router/switch, firewall, LTE gateway, and site networking
– Charger controllers / communication modules (where separable from power stage)
– Monitoring devices and meters used for load management (CTs, gateways)
– Payment terminals and user interface screens (site-dependent)
– CCTV, access control, and cabinet management systems (site-dependent)
Most UPS systems are not sized to keep delivering full EV charging power, because that would require very large energy storage.
Common UPS Integration Architectures
– Network + backend continuity UPS
UPS supplies networking and gateways so chargers can reconnect quickly and maintain telemetry.
– Control power UPS
UPS supplies control circuits so chargers can perform safe shutdown, preserve state, and restart cleanly.
– Site cabinet UPS
UPS is installed in a street cabinet or electrical room to back up shared controls and comms for multiple chargers.
– Hybrid with stationary storage
Some sites use stationary battery storage for broader resilience/peak shaving and a smaller UPS for clean power to controls.
Operational Use Cases
– Ride-through of brief outages (seconds to minutes) without losing monitoring
– Protection against brownouts and short voltage dips that can crash electronics
– Maintaining remote access for troubleshooting during a local outage
– Controlled session handling: prevent abrupt cutoffs that cause failed billing records
– Faster recovery: chargers return to service without manual resets
Key Design Considerations
– Define the goal: ride-through vs graceful shutdown vs extended runtime
– Runtime sizing: critical loads (W) × required minutes + margin
– UPS placement: temperature, ventilation, maintenance access, and security
– Earthing and protection coordination (TN/TT/IT context, upstream breakers, RCDs)
– Monitoring: UPS health telemetry (battery status, alarms) integrated into alerts/ticketing
– Bypass and maintenance: safe service procedures without taking the site offline
– Cybersecurity: if the UPS is networked, secure its management interface (TLS, access control)
Common Pitfalls
– Oversizing expectations (“UPS will keep chargers running”) without realistic kW/kWh sizing
– Backing up the wrong loads (keeping routers on but losing the charger controller power)
– Poor ventilation leading to UPS battery degradation and frequent replacement
– No monitoring, so UPS batteries fail silently until the first outage
– Not coordinating restart logic, causing all chargers to come back online simultaneously and spike load
Best Practices
– Back up comms, control, and monitoring first—these give the biggest uptime benefit per cost
– Integrate UPS alarms into a ticketing system integration workflow
– Test outage scenarios during commissioning (failover and recovery behavior)
– Use staged restart and load management to prevent post-outage demand spikes
– Include UPS battery replacement in preventive maintenance planning and TCO models
Related Glossary Terms
Stationary Battery Storage
Load Management
Telemetry Streaming
Ticketing System Integration
Charger Uptime
Incident Response
Power Quality
Sub-distribution Board (SDB)