Starter-Current Testing

For a captured starter-current DC peak, our handheld pick is the Hioki CM4373-50, whose manual documents DC PEAK MAX/MIN and a minimum peak width of 1 ms with the filter disabled. For a saved current waveform aligned with battery voltage through cranking, choose a Pico TA167 with a PicoScope 4425A and the complete connection kit below. Buy according to the result you need: a peak value or a time record you can revisit.

Quick picks: buy the capture method

• Handheld peak: Hioki CM4373-50. Choose it for a documented DC peak function without a computer.
• Saved current plus voltage: Pico TA167 + PicoScope 4425A. Choose it when the timing and shape of the event matter.
• Only routine DC readings? Keep that purchase in our DC clamp-meter guide; require explicit DC capture evidence before using any ordinary display reading as a starting-current peak.

Compare specifications and all conditions

Exact hardware

Hioki handheld route

CM4373-50 base meter

Pico waveform route

TA167 probe + 4425A, PQ174 scope-only package

Current ranges

Hioki handheld route

600.0 A / 2000 A DC

Pico waveform route

200 A / 2000 A AC peak or DC

Capture evidence

Hioki handheld route

DC PEAK MAX/MIN; widths ≥1 ms, filter off

Pico waveform route

Current and voltage waveforms on the scope’s shared time axis

Maximum conductor diameter

Hioki handheld route

55 mm

Pico waveform route

32 mm

Power to plan for

Hioki handheld route

Two supplied LR03 alkaline batteries

Pico waveform route

TA167: 9 V alkaline battery; scope: computer USB

What to retain

Hioki handheld route

Peak readings; optional app snapshots have limits

Pico waveform route

Saved waveform data and vehicle/test details

Full comparison table ↔

Swipe to compare. Row labels stay visible.

Buying question	Hioki handheld route	Pico waveform route
Exact hardware	CM4373-50 base meter	TA167 probe + 4425A, PQ174 scope-only package
Current ranges	600.0 A / 2000 A DC	200 A / 2000 A AC peak or DC
Capture evidence	DC PEAK MAX/MIN; widths ≥1 ms, filter off	Current and voltage waveforms on the scope’s shared time axis
Maximum conductor diameter	55 mm	32 mm
Power to plan for	Two supplied LR03 alkaline batteries	TA167: 9 V alkaline battery; scope: computer USB
What to retain	Peak readings; optional app snapshots have limits	Saved waveform data and vehicle/test details

Buying question	Hioki handheld route	Pico waveform route
Exact hardware	CM4373-50 base meter	TA167 probe + 4425A, PQ174 scope-only package
Current ranges	600.0 A / 2000 A DC	200 A / 2000 A AC peak or DC
Capture evidence	DC PEAK MAX/MIN; widths ≥1 ms, filter off	Current and voltage waveforms on the scope’s shared time axis
Maximum conductor diameter	55 mm	32 mm
Power to plan for	Two supplied LR03 alkaline batteries	TA167: 9 V alkaline battery; scope: computer USB
What to retain	Peak readings; optional app snapshots have limits	Saved waveform data and vehicle/test details

Best for a DC peak: Hioki CM4373-50

Hioki’s CM4370-series starter example explicitly describes instantaneous DC current extremes when an engine starts. The CM4373-50 manual then supplies the model-specific evidence: DC PEAK MAX/MIN and a peak-detection time width of 1 ms or more with the filter disabled. That is why this is our peak pick; its generic INRUSH label is not the basis for the recommendation.

Use the right capture function. Hioki separates MAX/MIN/AVG, which follow the displayed measurement interval, from PEAK, which follows waveform extremes after 10 kHz sampling. The ordinary DC-current display updates 5 times/s, so watching it during cranking is not equivalent to arming PEAK. The manual excludes MAX/MIN/AVG/PEAK from Auto AC/DC mode: select the DC-current function, zero the meter and follow the manual’s PEAK procedure before the event.

Read the peak accuracy row. On the 600.0 A range, the DC peak table specifies ±10 A to ±1500 A, 1 A resolution, and ±(1.3% of reading + 7 A). That differs from the 0.1 A step in the ordinary DC table; do not assign the normal display’s finer step or accuracy to the captured peak. The ordinary current ranges are 600.0 A and 2000 A, with a 55 mm maximum conductor diameter. Check physical clearance around the cable as well as its diameter before ordering.

Resolve the US package name. The US product page is headed CM4373-90, but its order table also lists CM4373-50 without Z3210. This pick is the base -50 package: L9300 leads, C0203 case and two LR03 alkaline batteries are listed accessories. The -90 adds the wireless adapter; -93 adds that adapter and the P2010 high-voltage probe. Those extras are not prerequisites for the handheld DC peak route.

The app nuance matters. With Z3210, Hioki offers GENNECT Cross waveform display, including retrieval of two saved inrush waveforms. The app’s Waveform Graph/FFT specifications list one instrument connection and JPEG saving without waveform measured values. We therefore recommend the scope when the deliverable is a reusable current-and-voltage cranking record, rather than assuming these snapshots provide the same workflow.

Check the exact Hioki package

Best for saved waveforms: Pico TA167 with PicoScope 4425A

The TA167 is a current-to-voltage probe: its 2 m safety-BNC cable connects to the recorder; the probe alone is not this capture system. Its manual confirms 200 A and 2000 A ranges, while the product page specifies 10 mV/A and 1 mV/A switchable sensitivities. Use 10 mV/A for the 200 A range and 1 mV/A for the 2000 A range. Match the software’s probe scaling to the selected hardware range; do not expect the BNC probe to auto-configure like a PicoBNC+ clamp.

The 32 mm conductor opening is smaller than the Hioki’s 55 mm opening. Pico specifies a load of more than 100 kΩ and no more than 100 pF; the 4425A input is 1 MΩ in parallel with 24 pF, and its PicoBNC+ sockets accept existing BNC probes. This documents the electrical load and connector match rather than relying on the connector’s appearance alone.

Do not combine the headline limits. TA167 bandwidth is DC to 20 kHz (−1 dB), subject to I_RMS × f ≤ 400,000. The maximum-current headline is not permission to measure full-scale alternating current throughout that bandwidth. The probe requires a 9 V alkaline battery, zeroing away from the current-carrying conductor, and attention to its automatic power-off setting.

TA167 versus TA388: the TA388 uses PicoBNC+, draws power from the scope, and automatically configures, ranges and zeroes when connected. Consider that alternative for a new 4425A setup if you want those conveniences; keep TA167 when ordinary BNC output is the requirement. The TA388 requires a PicoBNC+ recorder such as 4225A or 4425A; it is a different part, not an included TA167 upgrade.

Check TA167 probe details · Check the 4425A recorder options

Buying guide: order a working recorder setup

This is an assembled shopping list for current plus battery voltage, not the name of a factory bundle. Compare the whole order before choosing the probe.

Package traps: PQ176 is the four-channel Starter Kit with PicoBNC+ test leads and selected adapters; PQ174 is scope only. A “Starter Kit” name is not a promise of a starter-current probe: explicitly include the chosen clamp in the order. The 4225A has two channels, enough for a current-and-voltage pair; the 4425A has four, and Pico reserves its automated battery-to-starter cable voltage-drop/resistance assessment for four-channel scopes. That expansion is our reason to choose the 4425A here.

• Yes: A single DC peak is the deliverable: the Hioki route fits.
• Yes: Current and voltage must be compared in time: the scope route fits.
• Partly: Hioki app waveform snapshots: available with the adapter, with JPEG/data-export limits.
• No: A Pico test-and-measurement scope is not an Automotive-software substitute.

Before ordering, install the intended software release and try demo mode on the intended computer. Pico explicitly excludes its Test & Measurement scopes, including the 2000 Series, from Automotive software support. Use our beginner oscilloscope guide for general bench choices; this purchase needs the documented automotive recorder/software pairing.

Capture a useful record, then interpret it

For the scope route, retain DC coupling to preserve the signal’s DC level; AC coupling removes the offset. Use a timebase covering the event and enough samples to retain its detail; a longer time window without adequate sampling can lose information. A single trigger can capture the first qualifying event, and pre-trigger positioning retains context around its start.

1. 1

   Establish the connections

   Follow the maker’s battery-test connection guide and the vehicle’s service procedure; identify the intended current path.

2. 2

   Prepare the probe

   Connect the TA167 to the recorder before fitting it around the conductor; zero it away from current.

3. 3

   Set the capture

   Match probe scaling and range, preserve the DC level, and choose the trigger and time window for the event.

4. 4

   Review and retain

   Check the full event for over-ranging; save waveform data with the vehicle and test details.

Pico illustrates cranking captures with battery voltage and starter current together; that supports examining voltage behaviour at the same moment as current, rather than comparing unrelated extremes. Save the Psdata capture for later waveform work, and include the range and connection context in the test details. Do not turn a current maximum into a diagnosis by itself: Pico’s fuller battery test also uses battery specifications and ambient temperature.

For ordinary lead-based vehicle checks, use our automotive multimeter guide. Keep the routine meter and the event recorder as separate buying decisions.

How we choose

These recommendations compare official product pages, model-specific manuals, capture specifications, connector/load compatibility and documented package options. They are based on manufacturer documentation, not physical testing. We distinguish a current probe from its recorder, ordinary MAX/MIN from DC peak capture, and waveform snapshots from reusable multichannel data. Our selection method explains the research approach; no Amazon listing has been verified for these new records.

Verdict

Choose Hioki CM4373-50 for a documented handheld DC peak, provided its timing, range and jaw suit the job. Choose TA167 + PicoScope 4425A with the voltage lead, clips and computer for saved current-and-voltage waveforms; consider TA388 if you prefer the PicoBNC+ power and configuration conveniences. If neither capture result is needed, stay with a routine DC clamp rather than buying this recorder setup.