Building a High-Throughput EV Charging Depot: Lessons from Zeem Solutions’ LAX Milestone

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Overview

In early 2025, electric logistics firm Zeem Solutions celebrated a landmark achievement: its commercial charging depot at Los Angeles International Airport (LAX) surpassed 350,000 successful charging sessions. This milestone, announced at ACT Expo, underscores the depot’s status as one of the highest-throughput EV charging facilities in the United States. But what does it take to design, deploy, and operate a charging hub that can handle thousands of sessions reliably? This guide distills the principles behind Zeem’s success into a practical blueprint for fleet operators, facility managers, and energy consultants. You’ll learn the prerequisites, step-by-step implementation strategies, and common pitfalls to avoid when building a high-uptime, high-volume charging station.

Prerequisites

Before diving into construction and operation, ensure you have the following foundational elements in place:

• Site Selection and Power Capacity: A location with access to high-voltage (e.g., 480V, 1–2 MW) grid connections. Zeem’s LAX depot likely uses dedicated substations. Work with utility providers to confirm transformer and feeder availability.
• Fleet Composition and Charging Profiles: Know your vehicles – battery sizes, charging rates (e.g., 50–350 kW DC fast charging), and typical dwell times. For a mixed fleet of delivery vans and trucks, plan for varied session lengths (30 minutes to 4 hours).
• Charging Hardware Portfolio: Invest in reliable, standards-compliant chargers (CCS, CHAdeMO, NACS adapters). Choose vendors with proven uptime records and remote monitoring capabilities.
• Energy Management System (EMS): A software platform to monitor, schedule, and load-balance charging sessions. Examples include Ampcontrol, PowerFlex, or custom SCADA systems.
• Operational Team: Dedicated technicians for maintenance, a data analyst for session tracking, and a shift supervisor for real‐time issue resolution.

Step-by-Step Implementation Guide

Step 1: Conduct a Capacity and Demand Analysis

Begin by modeling your expected daily charging sessions. For a depot targeting over 350,000 sessions (like Zeem’s over a few years), estimate a baseline of 200–500 sessions per day. Use historical fleet data to create a load profile. Example calculation using simple Python:

import pandas as pd
sessions_per_day = 400  # target
avg_session_kwh = 80    # assume 80 kWh per session
daily_energy = sessions_per_day * avg_session_kwh
print(f'Daily energy demand: {daily_energy} kWh, power peak ~ {daily_energy/16} kW (assuming 16h operation)')

Ensure your utility can supply this demand. Work with engineers to design a medium-voltage distribution system with redundancy (e.g., N+1 transformers).

Step 2: Design the Physical Layout

Optimize parking stalls for both vehicle maneuverability and cable reach. Zeem’s LAX depot likely uses pull-through bays for larger trucks. Consider:

• Charger-to-stall ratio: 1:1 for high-utilization; 1:2 if queuing is acceptable. For 50 stalls, install 50 chargers.
• Cable management: Ceiling-mounted retractable systems to avoid trip hazards and cable wear.
• Weatherproofing: NEMA 3R enclosures for chargers, canopies for shade and rain protection.

Create a site plan using CAD or GIS tools.

Step 3: Procure and Install Charging Equipment

Select chargers with high reliability (MTBF > 100,000 hours). For a depot targeting 350,000 sessions, reliability is critical. Negotiate service-level agreements with manufacturers for 2-hour response time. Installation steps:

1. Pour concrete pads for charger pedestals.
2. Run conduit and pull cables from switchgear to each charger.
3. Mount chargers, connect communication cables (Ethernet or cellular backup).
4. Commission each charger with a test session using a known vehicle – verify metering, power output, and authentication.

Step 4: Implement a Charging Management Software

Deploy an EMS that can handle session initiation, billing, and load management. Zeem likely uses an advanced platform that tracks each session’s start/end time, energy delivered, and error codes. Key features:

• Session logging: Store every charge event in a database. Example schema:

CREATE TABLE charging_sessions (
  session_id INT AUTO_INCREMENT,
  vehicle_id VARCHAR(20),
  charger_id VARCHAR(10),
  start_time DATETIME,
  end_time DATETIME,
  energy_kwh DECIMAL(8,2),
  status ENUM('success', 'failure', 'interrupted'),
  PRIMARY KEY (session_id)
);

• Real-time monitoring dashboard: Display current utilization, power draw, and queued sessions. Use Grafana or Tableau.
• Automatic failover: If a charger stops responding, reroute the next vehicle to an available unit.

Step 5: Establish Maintenance and Reliability Protocols

To reach 350,000 successful sessions, uptime must exceed 99.5%. Implement:

• Weekly inspections: Check connectors for debris, cable insulation for wear, and cooling fans for chargers.
• Predictive maintenance: Use historical error logs to anticipate failures. For example, if charger #7 shows increasing “comm error” counts, schedule a firmware update or hardware swap.
• Spare parts inventory: Stock common replacement modules (contactors, power supplies) on-site.

Train technicians to perform “swap and repair” – replace a faulty charger quickly, then repair offline.

Step 6: Monitor and Optimize Throughput

Track key performance indicators (KPIs):

• Successful session rate: (# of completed sessions) / (total attempted). Target >98%.
• Average session duration: If sessions are too long, power limit chargers or implement idle fees.
• Charger utilization: (total energy delivered / (number of chargers × available hours)). Ideal is 50–70% – below 30% indicates oversizing; above 90% risks congestion.

Use A/B testing to adjust power capping during peak demand. For instance, limit maximum power to 80% during heavy load to avoid tripping breakers.

Common Mistakes to Avoid

• Underestimating Power Infrastructure Costs: Many projects fail because they assume existing transformers can handle the load. Always budget for new substations or upgrades. Zeem’s LAX site likely required tens of millions in grid work.
• Ignoring Cable Management: Tangled cables cause downtime and safety hazards. Invest in retractor systems and protective sheaths.
• Not Planning for Peak Demand: If 80% of vehicles arrive between 8–10 PM, chargers may queue. Install enough stalls to meet 85th percentile demand, and consider reservation systems.
• Neglecting Software Integration: Without a centralized EMS, operators struggle to identify failing chargers. Zeem’s success highlights the need for robust session tracking.
• Poor Staff Training: Technicians must be able to diagnose and fix issues quickly. Create a runbook for common error codes (e.g., “Session aborted due to ground fault”).

Summary

Zeem Solutions’ 350,000 successful charging sessions at LAX prove that a high-throughput EV depot is achievable with careful planning, reliable hardware, and rigorous operational protocols. This guide outlined the prerequisites – from power capacity to team skills – and a six-step process covering analysis, layout, equipment, software, maintenance, and optimization. By avoiding common pitfalls like underestimated infrastructure or poor cable management, fleet operators can replicate Zeem’s milestone. Focus on reliability metrics, proactive maintenance, and data-driven decisions to keep your charging sessions successful, every time.