About this replacement
Minelab Equinox 600 / 800 — 3.7V Li-ion Replacement Battery (3011-0405)
This 3.7V, 5000mAh Li-ion battery replaces OEM part 3011-0405 in the Minelab Equinox 600 and Equinox 800 metal detectors. It fits directly into the waterproof battery compartment on both models, which share the same cell format, connector, and BMS handshake protocol. Capacity is 18.5Wh — matched to the original specification.
- Equinox 600 and 800 compatibility: Both detectors run the same 3.7V cell bay with an identical physical footprint and BMS communication line. One battery covers both platforms without any modification to the compartment or contacts.
- Bench tested on actual hardware: We cycled this pack through the Equinox power-on sequence and multi-frequency switching. The BMS negotiated charge state correctly and did not trigger a cutoff during the frequency shift current draw at startup.
- Post-install detector calibration: After fitting, run a full ground balance and noise cancel cycle before your first sweep. The Equinox maps battery state during initialisation — skipping this causes early low-battery warnings that don't reflect actual charge level in the field.
Why the Equinox 600 shuts down during multi-frequency startup
Switching into Multi-IQ mode pulls a brief current spike as all active frequencies initialise simultaneously. On a degraded original battery, internal resistance has risen enough that this spike causes the cell voltage to sag below the BMS cutoff threshold — typically around 3.0V — and the detector powers off immediately. A fresh pack with low internal resistance handles the spike without dropping into cutoff. If shutdowns happen consistently at mode switch, the cell is the cause, not the coil or control board.
Battery percentage jumping or resetting after installing a new pack
The Equinox fuel gauge is calibrated against the charge curve of the installed cell. A new pack has a slightly different resting voltage profile than the depleted original, so the displayed percentage can jump, reset, or read inconsistently for the first few cycles. This is not a fault with the replacement — it is the detector recalibrating its voltage-to-percentage mapping. Run two or three full charge and discharge cycles to let the indicator settle. After that, readings should track accurately from 4.2V full to the low-battery threshold near 3.5V.