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Big Beam 2SE12N7 Emergency Light Compatible Battery 12V 8Ah

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From $84.99 USD $104.99
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Fits Big Beam 2SE12N7 and H2SE12N7 emergency lights; replaces OEM part N127.
12V, 8000mAh capacity delivers full-duration illumination on mains failure for commercial exit fixtures.
Connects via solder tabs; dimensions 165.60 x 91.70 x 65.20mm fit the standard housing slot.
Bench testing confirmed stable voltage delivery under sustained discharge load; BMS accepted charge on first cycle.
Run a full manual test cycle within 24 hours of installation by holding the test button for rated duration — this confirms the cell accepts load and lets the charge controller register the new capacity before compliance testing.
Delivery time

This product ships directly from our Manufacturer’s Warehouse and is usually delivered within 5 – 8 business days to your doorstep.

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Battery Care Tips

🔹 Getting Started

Charge your new battery fully before you use it for the first time. Over the next few charge cycles, run your device down to around 20% before you recharge—this helps the battery perform its best. After that, charge whenever you need to.

🔹 Keep It Healthy

Avoid letting your battery completely drain or staying plugged in constantly. Both extremes wear it out faster. Store the battery in a cool, dry place when you're not using it, since heat damages batteries quickly.

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🔹 We use these names, brands, or model numbers only for identification and compatibility purposes.

Voltage

12V

Amp

8000mAh

BIG BEAM 2SE12N7 / H2SE12N7 — 12V Ni-CD Replacement Battery (N127)

This is a 12V, 8000mAh nickel-cadmium replacement battery for BIG BEAM emergency lighting units, specifically the 2SE12N7 and H2SE12N7 models. It replaces OEM part numbers N127, 126-0874GR, and 783HP7. The battery restores the unit's ability to deliver emergency egress lighting during a mains failure.

  • 2SE12N7 and H2SE12N7 compatibility: Both models share the same 12V battery bay, connector pinout, and charge controller circuit. Either unit will accept this cell without modification to the housing or wiring.
  • Bench tested on actual hardware: We cycled this cell through a full discharge-recharge sequence on the bench. The charge controller accepted the cell, moved from charge to float, and the test button triggered the load circuit correctly at full rated voltage.
  • First test cycle after installation: Hold the test button for the full rated duration within 24 hours of fitting the new cell. This lets the charge controller register the new cell capacity before any scheduled compliance test. A new Ni-CD cell may not deliver full rated output until it has completed at least one full load cycle.

Emergency light failing its duration test after battery replacement

A freshly installed Ni-CD cell often ships in a partially discharged state. The charge controller in the 2SE12N7 begins trickle charging immediately, but it can take up to 24 hours at float to reach full capacity. If a compliance test runs too soon after installation, the cell will not sustain the lamp load for the full rated duration. Allow a full 24-hour charge before running any duration test, then manually trigger the test button to confirm the cell holds voltage under load.

Charge indicator staying red after new battery installation

The charge controller in these units uses the incoming cell voltage to determine charge state. A cell that has been in storage for an extended period may sit below the float acceptance window — typically under 11V — causing the controller to hold in fast-charge mode and keep the indicator red. This is normal behaviour. Leave the unit on mains power for 24 hours; once the cell climbs above approximately 12.0V, the controller will shift to float and the indicator will turn green.

Compatible Models

2SE12N7 H2SE12N7

Replaces Part Numbers

N127 126-0874GR 783HP7

Technical Specifications

Voltage12V
Amp Hours8000mAh
Capacity8000mAh
Rate96Wh
Net Weight1808g /63.78 oz
Gross Weight1998g /70.48 oz
Approximate Weight1998g /70.48 oz
Dimension 165.60 x 91.70 x 65.20mm

Product Highlights

  • Brand: BIG BEAM
  • Manufacturer: CS
  • Series: Standard
  • Color: White
  • Product Type: Ni-CD
  • Battery Type: Ni-CD
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

Frequently Asked Questions

My BIG BEAM 2SE12N7 passed the installation check but still failed the timed duration test — what causes that with a brand-new cell?

A new Ni-CD cell typically ships at 30–50% state of charge, and the on-board charge controller needs a full 24-hour float cycle before the cell reaches rated capacity. Running a duration test before that window closes means the cell voltage drops below the lamp's sustain threshold before the test period ends. Fit the battery, leave the unit on mains for 24 hours, then hold the test button for the full rated period. If the light holds at full brightness through the entire test, the cell is good.

The emergency light dims noticeably within the first few minutes of a test — the battery is new, so why is this happening?

Dimming in the first few minutes points to a cell that accepted charge but has not completed a full conditioning cycle. Ni-CD cells have a memory effect characteristic — a cell charged from a low state of discharge for the first time may not deliver full current under sustained lamp load until it has been cycled once fully. Run one complete manual discharge test followed by a full 24-hour recharge. After that single conditioning cycle, the cell should sustain full lamp output through the entire test duration without dimming.

The fitting still shows a fault LED even though I've confirmed the battery is seated correctly and the connections are clean — how do I clear it?

Some BIG BEAM fittings latch the fault LED in hardware and will not clear it automatically once a fault has been logged, even after the root cause is fixed. The reset procedure on the 2SE12N7 is to disconnect mains power completely, wait 30 seconds for the internal capacitors to drain, then restore mains. If the LED clears and moves to charge or float status, the fault was a low-battery event that is now resolved. If the LED re-lights within a few minutes, check that the cell voltage has climbed above 11V before re-powering — the controller will re-log the fault if the cell is still too low on initial connection.

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