Fusion Splicer Easy Splicer mk2 Compatible Battery 7.4V 3400mAh

Fusion Splicer Easy Splicer mk2 — 7.4V Li-ion Replacement Battery (RR201021)

This 7.4V, 3400mAh Li-ion battery replaces the OEM pack in the Fusion Splicer Easy Splicer mk2, EasySplicer Infralan Splicer HS 15C, and Infralan Splicer HS 15O. These are field-use fiber optic fusion splicers — the battery powers the arc electrode system, motor alignment drives, and the heating sleeve shrink cycle. Capacity is sourced from product data at 3400mAh (25.16Wh).

• mk2, HS 15C, and HS 15O compatibility: All three models run the same 7.4V battery rail and use the same physical connector and BMS handshake protocol. The cell footprint — 66.80 × 37.00 × 19.90mm — fits the shared battery bay across this splicer family without modification.
• Bench tested on actual hardware: We cycled this pack through arc-and-splice sequences and monitored BMS behaviour through the motor-drive and arc discharge events. The protection circuit held voltage within spec through repeated electrode firing without triggering a false cutoff.
• Post-install arc calibration: After fitting this battery, run the splicer's arc calibration routine before your first splice session. The splicer samples supply voltage during calibration to set arc power thresholds — skipping this step can cause inconsistent arc discharge or a premature low-battery warning mid-job.

Why the Easy Splicer mk2 shuts down at the sleeve heating step

The heat shrink sleeve cycle draws a sustained current load that sits above the arc discharge peak in duration. An aged or partially discharged cell can pass the arc event but sag below the BMS cutoff threshold during the longer heating cycle. The BMS reads this voltage drop as a depletion event and cuts output to protect the cells. A fresh pack at full charge resolves this — the heating step no longer pulls the cell voltage below the protection threshold.

Splicer not recognising new pack after it sat unused in the carry case

If the battery rested in the case for several months, the cell voltage may have dropped below the BMS sleep threshold — typically around 2.5V per cell. In sleep mode the BMS disconnects the output rail, so the splicer sees no pack at all. Connect the battery to its charger for at least 15–20 minutes before inserting it into the splicer; most chargers will push a recovery trickle charge sufficient to wake the BMS. Once cell voltage climbs back above approximately 3.0V per cell, the BMS re-enables output and the splicer recognises the pack normally.