Battery impedance tester
Updated 2026-10-27
Data records
- In the AC injection method the instrument passes a small alternating test current through the cell and derives the internal resistance from the alternating voltage drop that results; the same reading can be displayed as resistance or as conductance.
- Battery impedance testers are used on vented and valve-regulated lead-acid, nickel-cadmium and lithium-ion stationary batteries in substations, telecommunications sites, UPS installations, data centers and renewable power plants.
- Some cell resistance testers use a direct-current method instead, applying a brief DC load to the cell and computing the internal resistance from the voltage response, rather than injecting an alternating current.
- With a higher test current the instrument also measures the resistance of the intercell connection (strap) between adjacent cells, so that a poor or corroded connection is identified.
- A battery impedance tester reads the internal ohmic value of a stationary cell or module, shown as resistance or as conductance, together with the cell voltage, the temperature and the resistance of the connection to the next cell.
- No ohmic test reports the remaining capacity of a battery; only a discharge test does. Ohmic testing is the quick on-line screening test made between the infrequent discharge tests to flag cells that may be failing.
- The test is made on line with the battery in service, and the instrument rejects the charger ripple so that a cell can be read while it floats on the charger.
- Because an ohmic test compares a present reading with earlier ones, the battery is tested fully charged, so that successive readings share a common state of charge.
- An ohmic reading is a relative value: each result is compared with the cell's baseline and with the string average, and trending the readings over successive tests is what shows whether a cell is degrading and how soon it may fail.
Elsewhere in the family
- Battery Internal Ohmic Measurement related entry on Battery Testing Reference
- Battery Intercell Connection Resistance related entry on Battery Testing Reference
- Battery Capacity Load Test related entry on Battery Testing Reference
Sources
- Eagle Eye Power Solutions product page, IBEX-Series Portable Battery Resistance Tester, web page edition, Eagle Eye Power Solutions. Held as: Public page. Publisher page
- Fluke product page, Fluke 500 Series Battery Analyzer, web page edition, Fluke. Held as: Public page. Publisher page
- Megger product page, BITE5 battery tester series, web page edition, Megger. Held as: Public page. Publisher page
- Vertiv product page, Alber Cellcorder CRT-400 Cell Resistance Tester, web page edition, Vertiv. Held as: Public page. Publisher page
Changelog (21 entries)
| Date | Revision | Change |
|---|---|---|
| 2026-10-27 | created (instr.battery-impedance-tester.ac-injection-method) | |
| 2026-10-27 | revised (instr.battery-impedance-tester.ac-injection-method) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.battery-impedance-tester.ac-injection-method) | |
| 2026-10-27 | created (instr.battery-impedance-tester.applications) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.battery-impedance-tester.applications) | |
| 2026-10-27 | created (instr.battery-impedance-tester.dc-load-method) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.battery-impedance-tester.dc-load-method) | |
| 2026-10-27 | created (instr.battery-impedance-tester.intercell-connection-resistance) | |
| 2026-10-27 | revised (instr.battery-impedance-tester.intercell-connection-resistance) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.battery-impedance-tester.intercell-connection-resistance) | |
| 2026-10-27 | created (instr.battery-impedance-tester.measurand) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.battery-impedance-tester.measurand) | |
| 2026-10-27 | created (instr.battery-impedance-tester.not-a-capacity-test) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.battery-impedance-tester.not-a-capacity-test) | |
| 2026-10-27 | created (instr.battery-impedance-tester.online-test) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.battery-impedance-tester.online-test) | |
| 2026-10-27 | created (instr.battery-impedance-tester.state-of-charge) | |
| 2026-10-27 | revised (instr.battery-impedance-tester.state-of-charge) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.battery-impedance-tester.state-of-charge) | |
| 2026-10-27 | created (instr.battery-impedance-tester.trending-baseline) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.battery-impedance-tester.trending-baseline) |
Cite this page
Cite the governing standard for the fact itself; cite this page as the finding aid.
"Battery impedance tester." Test Instrument Reference. 2026-10-27. https://www.testinstrumentreference.com/instruments/battery-impedance-tester/.
Test Instrument Reference, Battery impedance tester (Oct. 27, 2026), https://www.testinstrumentreference.com/instruments/battery-impedance-tester/.
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title = {Battery impedance tester},
howpublished = {\url{https://www.testinstrumentreference.com/instruments/battery-impedance-tester/}},
organization = {Test Instrument Reference},
publisher = {Test Instrument Reference},
year = {2026},
note = {last substantive change 2026-10-27}
}{{cite web |title=Battery impedance tester |website=Test Instrument Reference |publisher=Test Instrument Reference |url=https://www.testinstrumentreference.com/instruments/battery-impedance-tester/ |date=2026-10-27 |access-date=}}