Legrand HB00015TA 6V Emergency Lighting Replacement Battery 2000mAh

Legrand 6600 Series — 6V Ni-CD Replacement Battery (HB00015TA)

This is a 6V, 2000mAh Ni-CD replacement battery for Legrand 6600 03, 6600 04, and 6600 05 emergency lighting units. OEM part numbers HB00015TA and 061885 cross-reference directly to this cell. It restores the backup illumination function that activates when mains power fails.

• 6600 03, 04, and 05 compatibility: All three models share the same 6V charge rail, cell format (210.40 × 23.00 × 23.00mm), and charge controller handshake — one cell fits all three without modification.
• Bench tested on actual hardware: We ran this cell through a mains-failure simulation. The charge controller accepted the cell voltage, moved from bulk charge to float, and the fitting activated correctly on loss of supply.
• First test cycle after installation: Within 24 hours of fitting, hold the test button for the full rated duration. This lets the charge controller register actual cell capacity before the next scheduled compliance inspection — skipping it risks a false fail on the duration test.

Emergency light failing its duration test after battery replacement

A freshly installed Ni-CD cell ships in a partial state of charge after months in storage. The charge controller in the 6600 series enters float at a fixed voltage threshold, not at full cell capacity. Until one complete charge-discharge cycle has run, the cell delivers less than its rated 2000mAh under load. Run a full manual test cycle on installation day and allow the fitting to recharge for 24 hours before the formal compliance test.

Charge indicator staying red after new battery is fitted

The 6600 series charge controller checks incoming cell voltage before committing to a charge cycle. A cell sitting at low voltage from long storage can fall outside the controller's float acceptance window, so the indicator stays red rather than transitioning to green. This is not a faulty cell — it is the controller refusing to start. Disconnect the cell, wait 30 seconds, reconnect, and the controller will retry; most cells recover to an accepted voltage range within the first hour of trickle charge.