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UT3550

Handheld Battery Tester

$1,679.00
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9 in stock

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Handheld battery tester with AC internal resistance method, 0.1 mΩ–30 Ω range, and 0.5% accuracy. Tests virtually all battery types from small consumer cells to large industrial installations for maintenance, QC, and troubleshooting.

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UNI-T UT3550 Handheld Battery Tester

Overview

The UT3550 measures battery internal resistance and voltage together using a 4-wire Kelvin connection and 1 kHz AC injection — the method that reveals a weak cell before it fails under load. It resolves internal resistance from 0.001 mΩ to 30 Ω at ±0.5% and voltage to 100 V at ±0.05%, covering everything from small consumer cells to large industrial battery banks.

A 4-wire connection removes lead resistance for accuracy at low ohms, a comparison function sorts pass/fail against set limits, and results log to 500 groups with CSV export over USB-C. The IP65 body and rechargeable pack suit field and maintenance work. It's backed by UNI-T's nearly 40 years of test-meter manufacturing.

Key Features

  • AC-injection internal-resistance method (1 kHz)
  • Internal resistance 0.001 mΩ to 30 Ω, ±0.5%
  • Voltage 0.0001 V to 100 V, ±0.05%
  • 4-wire Kelvin connection removes lead resistance
  • Comparison function with pass/fail sorting
  • Data logging to 500 groups; CSV export over USB-C
  • Dual display (LCD & OLED); IP65 sealing
  • Rechargeable 7.4 V 2000 mAh Li-ion

UT3550 Details

Internal Resistance & Voltage Together

Internal resistance rises as a cell ages, often well before its open-circuit voltage drops. By measuring resistance (0.001 mΩ–30 Ω) and voltage (to 100 V) at the same time, the UT3550 flags a weakening cell while it still reads a normal voltage.

4-Wire Kelvin Accuracy

A 4-wire Kelvin connection separates the current and sense paths so lead and contact resistance don't corrupt the reading — essential for the milliohm-level measurements that distinguish a healthy cell from a tiring one.

Sorting & Logging

A comparison function sorts cells pass/fail against set limits for fast battery-bank screening, and logging to 500 groups with CSV export over USB-C builds the record a maintenance program needs.

Field Build

A dual LCD/OLED display, IP65 sealing, and a rechargeable Li-ion pack make the UT3550 practical for moving down a rack of cells in the field.

Applications

UPS, telecom, and stationary battery-bank maintenance; testing consumer and industrial cells from small to large; incoming inspection and pass/fail sorting; and preventive programs that track internal resistance over time.

Frequently Asked Questions

Why measure internal resistance instead of just voltage?

Internal resistance rises as a battery ages, often before voltage drops — so it catches a weak cell earlier.

What is the 4-wire Kelvin method?

It uses separate current and sense leads so lead and contact resistance don't affect the milliohm-level reading.

Can I export results?

Yes — log to 500 groups and export CSV over USB-C.

Warranty

Warranty: 3 years. Contact us for details.