DEEP TECHNICAL CONTENT

Nickel-metal hydride battery

Nickel-metal hydride battery: A NiMH cell is in the ~1.2 V nominal class; pack voltage increases with series cell/module count. The page also includes a worked example and measurement sequence.

6 concrete technical facts1 worked example4 sources

Technical frame

Nickel-metal hydride battery: A NiMH cell is in the ~1.2 V nominal class; pack voltage increases with series cell/module count. The page also includes a worked example and measurement sequence.

The technical values here expose the standard, protocol or physical relationship directly; model-specific service values are linked through the matching model/variant dossier.

The goal is not only to define the term but to let the reader calculate and interpret what the data means in a scan, scope or physical test.

Concrete technical facts

  • A NiMH cell is in the ~1.2 V nominal class; pack voltage increases with series cell/module count.
  • Near full charge, NiMH behavior can be monitored through temperature rise and voltage response, while exact BMS algorithms are manufacturer-specific.
  • Under load, voltage delta among hybrid-pack blocks can reveal a weak module better than unloaded voltage.
  • Internal resistance can be estimated approximately from ΔV/ΔI during a current step.
  • A dirty cooling fan/duct can increase temperature spread and cause power limitation.
  • SOC, capacity and power capability are different concepts; high SOC does not exclude poor SOH.

Worked example

  • Internal-resistance example: if a 20 A load step drops block voltage by 0.30 V, R≈ΔV/ΔI=0.30/20=0.015 Ω, or 15 mΩ.

Measurement and verification sequence

  • Record block voltages during the same load step.
  • Observe min/max temperature and fan command/current.
  • Compare block internal-resistance trend using ΔV/ΔI.
  • Verify whether voltage delta recovers after charge/discharge.

Fault-separation logic

  • Is a valid command present and are power/ground/network healthy?
  • Does feedback follow the command?
  • Does an independent physical measurement confirm the output?
  • Is the fault limited to a specific temperature/load/speed condition?
  • Does the result remain stable when the original condition is repeated after repair?

Technical sources

  1. UNECE Vehicle Regulations / WP.29
  2. European Union vehicle type-approval framework
  3. AutoAtlas teknik editoryal sınıflandırması
  4. ISO standards catalogue · road vehicles

Continue investigating

Model-specific real technical data · Measurement references · Technical diagnostic atlas