EV Charger FAT and SAT Checklist: Define Acceptance Before Shipment

FAT, SAT and commissioning answer different questions.

A factory acceptance test (FAT) should confirm the ordered configuration and repeatable functions that can be exercised in a controlled factory setup before shipment. A site acceptance test (SAT) should confirm that the delivered unit is correctly installed and works with the site's real electrical, communications and operating environment. Commissioning is the broader quality-assurance process that connects installation checks, functional testing, correction of deficiencies, documentation and operator training before handover.

Do not use these labels as substitutes for a test plan. For every line item, name the exact model and serial number, hardware options, firmware, connector arrangement, test preconditions, action, expected result, evidence file, witness, owner and rule for retesting. A pass/fail box with no evidence is difficult to audit later.

Freeze the configuration before the FAT.

The test unit must match the purchase scope. Record cabinet model, rated total output, gun count, connector types, charging-cable length, display option, metering and payment hardware when applicable, network interfaces, OCPP version and enabled functions, firmware identifiers, language pack and destination-market configuration. Photograph identification labels and connector arrangement, and tie every report to the same serial number.

For Xiaochong projects, this matters because the portfolio is configurable. The commercial DC range includes 20–400 kW configurations; new ultra-slim dual-gun products cover 60–240 kW; four-gun options are 80, 120, 160 or 240 kW total cabinet power—not guaranteed power per connector. Charging cables are generally 5 m standard and can be reviewed for shorter or longer project-specific lengths. Applicable configurations can discuss 260–485 V AC input and custom wider input. None of these family-level descriptions replaces the selected model's written specification.

What to witness at the factory.

• Identity and build: reconcile purchase order, bill of materials, labels, options, cable and connector arrangement, supplied accessories and visible workmanship.
• Power-up and user interface: record startup, screen and language behavior, authorization paths and controlled stop. The outdoor high-brightness capacitive touchscreen claim should be tied to the ordered display option, not assumed for an unspecified unit.
• Charging journey: use agreed compatible vehicles or an appropriate test system to demonstrate connect, authorize, start, energy transfer, normal stop and session record. Record vehicle state of charge and accepted power; the vehicle can limit delivered power.
• Multi-output behavior: when more than one gun is used, document the configured power-sharing logic and concurrent test conditions. A four-gun cabinet's total rating cannot be divided into a universal per-gun promise.
• Backend behavior: demonstrate only the OCPP messages and remote actions included in the agreed profile. Save timestamps, charger identity, transaction/session identifiers and backend evidence.
• Fault response: use approved, non-destructive scenarios defined by the responsible engineers. Confirm safe stop and useful records without bypassing interlocks or opening energized equipment.
• Evidence package: retain test reports, photos, logs, configuration export where agreed, unresolved punch items and written retest results.

What must wait for the real site.

The factory cannot prove the final foundation, protective devices, conductor sizing, earthing, utility interface, upstream capacity, site voltage quality, network signal, firewall rules, accessibility, bay layout, drainage, lighting or local inspection. Those items belong to qualified local design, construction, inspection and SAT records.

At site, first confirm that approved installation and local inspection steps are complete. Then test communications and backend enrollment, each configured authorization path, a charging session with representative fleet vehicles, simultaneous-use behavior, payment and reconciliation when included, remote monitoring, controlled recovery after an agreed loss of communications, customer support routing and the accuracy of public location information when the site will be listed. Record the initial state of charge and vehicle limits so a low result is not automatically blamed on the charger.

OCPP evidence is version- and product-specific.

An OCPP name on a quotation does not by itself prove that the ordered hardware, firmware, optional functions and buyer backend will work together. Ask which exact charging-station product and software version any certificate or report covers, which profiles and optional functions were tested, and whether the evidence is an independent OCA certificate or a vendor-generated test report.

The Open Charge Alliance states that a Vendor Declaration of Conformance is not independently checked in the same way as certification, and that a certified software stack does not automatically certify every charging station using it. Buyers can check official certificates against OCA's certified-product list and still need project integration tests. Xiaochong has helped multiple customers work toward required certifications; contact customer service for model- and market-specific information rather than assuming every model has every approval.

Close the punch list before commercial handover.

Define which findings block shipment, energization, public use or final payment. Each item should have an owner, due date, corrective action, evidence and witnessed retest. Handover should include the as-built site and electrical documents supplied by the responsible parties, selected-product manuals and data sheets, test and inspection reports, configured account and escalation ownership, operator training, agreed spare-parts information and maintenance responsibilities.

Keep certification, permitting, utility approval, metrology, payment-network approval and local electrical acceptance as separate evidence lines. A successful charge session does not automatically prove any of them. Likewise, protocol conformance is not a warranty of total product quality or site reliability.

Ten questions to put in the purchase order.

1. Which exact hardware, firmware and optional functions are under test?
2. Which tests occur at FAT, SAT and post-handover monitoring?
3. What preconditions—including vehicle state, temperature and network—must be recorded?
4. What measurable expected result and tolerance applies to each test?
5. Which evidence files are delivered and who witnesses them?
6. Which multi-gun and power-sharing scenarios are required?
7. Which OCPP, remote-control, payment and reconciliation paths are in scope?
8. Which local inspection and utility approvals remain the buyer's or installer's responsibility?
9. Which failures block shipment or service, and how are retests approved?
10. What training, manuals, as-builts, spares and escalation contacts close handover?

Common buyer questions.

Primary technical sources.

These official sources support the process principles. Destination-market regulations, approved engineering documents and selected-model procedures control the final project.

• Joint Office of Energy and Transportation — Ensuring a Reliable Charging Experience ↗
• U.S. DOE Alternative Fuels Data Center — Electric School Bus Planning Guide, charger activation and commissioning documents ↗
• Open Charge Alliance — OCPP Certification Program ↗
• Open Charge Alliance — Vendor Declaration of Conformance and its limits ↗
• Open Charge Alliance — Certificate verification ↗