AVHzY CT-3 vs POWER-Z KM003C

For most USB-C charger and cable buyers, choose the POWER-Z KM003C: documented EPR support and a 50 V ceiling make it the clearer choice for high-power USB-C charging. Choose AVHzY CT-3 for Lua scripts, faster offline capture and a compatible SM-LD-00 load setup, after checking its voltage and package restrictions. These recommendations come from official product pages and manuals.

Quick picks: analyzer or charger-test kit?

Compare specifications and all conditions

USB-C charger profiles, cable e-markers and EPR

Our choice

POWER-Z KM003C

Buying condition

Use an appropriate EPR cable and plan on Windows for PC analysis

USB-A connections, Lua automation and faster offline capture

Our choice

AVHzY CT-3 standalone

Buying condition

Resolve the exact hardware's voltage limit before ordering

A meter plus a controllable charger load

Our choice

CT-3L+Load, product code CT3+Load (sm-ld-00)

Buying condition

Confirm the load revision and continuous-power rating

Adding a load to a compatible CT-3 already owned

Our choice

SM-LD-00 accessory

Buying condition

The maker explicitly excludes CT-3A

Full comparison table ↔

Swipe to compare. Row labels stay visible.

Your priority	Our choice	Buying condition
USB-C charger profiles, cable e-markers and EPR	POWER-Z KM003C	Use an appropriate EPR cable and plan on Windows for PC analysis
USB-A connections, Lua automation and faster offline capture	AVHzY CT-3 standalone	Resolve the exact hardware's voltage limit before ordering
A meter plus a controllable charger load	CT-3L+Load, product code CT3+Load (sm-ld-00)	Confirm the load revision and continuous-power rating
Adding a load to a compatible CT-3 already owned	SM-LD-00 accessory	The maker explicitly excludes CT-3A

Your priority	Our choice	Buying condition
USB-C charger profiles, cable e-markers and EPR	POWER-Z KM003C	Use an appropriate EPR cable and plan on Windows for PC analysis
USB-A connections, Lua automation and faster offline capture	AVHzY CT-3 standalone	Resolve the exact hardware's voltage limit before ordering
A meter plus a controllable charger load	CT-3L+Load, product code CT3+Load (sm-ld-00)	Confirm the load revision and continuous-power rating
Adding a load to a compatible CT-3 already owned	SM-LD-00 accessory	The maker explicitly excludes CT-3A

Comparison table: the differences that change the purchase

Sources: CT-3 store, main specifications, meter manual, PC manual, KM003C product page, current KM003C manual, KM003C launch description and load listing.

Why the voltage conflict matters: USB-IF identifies 28 V, 36 V and 48 V EPR fixed-voltage levels, corresponding to 140 W, 180 W and 240 W. CT-3's 26 V store specification cannot accommodate those voltages. Its alternative 29 V specification would still not establish EPR negotiation or full-voltage EPR capability. Our recommendation is KM003C for EPR; do not infer PD support from “USB 3.1” in CT-3's title, which its manual discusses as data signaling.

Best USB-C analyzer: POWER-Z KM003C

KM003C is our first choice when you want to inspect a charger's advertised power profiles, read a cable's e-marker and analyze USB PD traffic. Its product page documents those tests and the voltage ceiling; the manual explicitly lists EPR. For broader alternatives, use our USB-C power meter guide.

Buy it for analysis, then choose the load separately. ChargerLAB attributes extra protocol-detection capabilities to a built-in load. That does not establish an adjustable high-power load comparable to the AVHzY accessory. Our reading of the documented functions: requesting a charger profile establishes negotiation; evaluating sustained output also requires a suitable load.

For EPR protocol tests, the manual describes cable simulation but says it is imperfect; where it fails, it calls for a 240 W cable in the receptacle. Do not assume the tester's own rating upgrades a cable. Our USB-C cable tester guide covers the separate cable-selection decision.

The support FAQ also discloses a hardware issue with some USB 2.0 peripherals, including mice and keyboards. Although the manual specifies USB4-capable measurement connectors, compatibility with every attached data device is not assured.

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Best for Lua and faster offline capture: AVHzY CT-3

CT-3 earns its place through the combination of Lua programs that can run on boot, USB-A connections and faster offline logging. Its main specifications also list cable resistance testing, e-marker reading and a PC PD listener. Choose it when that workflow matters more than documented EPR support.

Both analyzers record offline. CT-3's manual permits 1–100 samples/s and lets you mount internal storage over USB. Its PC manual describes opening offline files and exporting CSV. KM003C also stores curves offline, but its documented interval starts at 1 second. Choose CT-3 for denser standalone capture; choose KM003C when its recording interval suits the charging session.

For either instrument, choose the interval around the event you need to see. A faster capture rate does not by itself establish better measurement accuracy or longer recording time. CT-3's memory is shared with programs; KM003C imposes the per-group point limit shown above.

CT-3's data pass-through also needs care: the manual says USB 3.1 support is partial and not guaranteed for every signal path, despite the product page's broader SuperSpeed wording. Avoid buying either analyzer as a guarantee that a particular dock or storage device will work through it.

Check the standalone CT-3 package at AVHzY.

Best matching load route: CT-3L+Load or SM-LD-00

The SM-LD-00 listing specifies 2.5–26 V, 0.05–6.7 A and 100 W continuous at 25°C ambient. AVHzY's CT-3 page documents constant-current and constant-power control from the meter or PC. The module's current rating does not raise CT-3's separately stated 6 A measurement limit; size the complete arrangement to its limiting component.

The sustained-power claim needs clarification. AVHzY's administrator download post instead describes 65 W (Max 100 W). These are conflicting maker descriptions. If sustained 100 W loading is the reason for buying, get the applicable revision and operating conditions confirmed before choosing this kit. Either description leaves the module unsuitable for EPR voltages above its voltage ceiling.

One more naming trap: the old meter manual calls its module SM-LD-01, while the current store sells SM-LD-00. Use the current accessory's exact identifier and compatibility statement; do not silently treat those labels as interchangeable.

• Yes: CT-3 plus its documented compatible load: the AVHzY bench route
• No: CT-3A plus SM-LD-00: explicitly excluded by the accessory listing
• Partly: Continuous maximum-power loading: resolve the maker's conflicting ratings first

Buying guide: software, power and the usable package

Plan the computer before buying for logs or protocol analysis. POWER-Z's FAQ says Windows 10 or later in its connection troubleshooting answer. Its manual's version history records Windows 7 support integrated into the PC software, without a separate Windows 7 release. The manual lists Windows / Mac OS software, with Mac OS marked as in development. The manual calls HID driver-free; the FAQ discusses automatic driver installation and a manual fallback. Follow the current support instructions for your system.

AVHzY's download thread provides PC software and a Windows 7 workaround driver package (shizuku_workaround_driver_for_win7.zip), but its fetched manuals do not establish a current Windows/macOS/Linux support matrix. Treat native Mac and Linux software support as unconfirmed for this purchase.

Record the revision and firmware. The AVHzY thread lists 10067.zip as CT-3 firmware and 10020.zip as PC software. Its UI manual is V1.00.00 and explicitly warns that hardware and firmware revisions may differ. The newest tester entry in the fetched POWER-Z changelog is V2.0.7; its newest PC entry is V2.5.1. Those release notes include offline-recording fixes, so record your installed versions when comparing logs. A download filename does not identify the board revision shipped in a US package.

Budget for the connection, not an assumed box inventory. The fetched AVHzY package descriptions and KM003C product text do not provide a complete included-cable list. Confirm it before checkout. CT-3's PC connection requires a micro-USB data cable; KM003C uses its USB-C HID port for PC connection and auxiliary power. Its manual requires sustained HID power for protocol tests. Have the appropriate data lead, power source and test cable ready.

For ordinary CT-3 pass-through measurement, the manual instructs you to turn the PD communication switch off after trigger/listener use. Follow the separate listener instructions when analyzing traffic. It also prohibits adding another test device to spare measurement ports while monitoring a connection.

1. 1

   Match the instrument

   Select KM003C for documented EPR or CT-3 for its Lua and offline-capture workflow.

2. 2

   Match the accessory

   Check the exact meter code, load compatibility and confirmed operating limits.

3. 3

   Match the computer and cables

   Verify host support, data cable, auxiliary power and the package's packing list.

How we choose

We compared official store listings, manuals, support FAQs and firmware notes, fetched November 2, 2026. We prioritized documented negotiation, voltage limits, offline recording and the exact load package. We have no physical measurements to report; compatibility gaps and contradictory maker statements remain identified. See how we choose.

Verdict

Buy KM003C for USB-C/EPR analysis. Buy CT-3 for Lua, USB-A and faster offline capture. Choose the named CT-3L+Load package or compatible SM-LD-00 accessory only after resolving sustained-load requirements; CT-3A is excluded from that accessory path. If you're comparing FNIRSI instead, use our separate KM003C vs FNB58 comparison.