About this replacement
Honeywell EK210 / EK280 Series — 3.6V Li-SOCl2 Replacement Battery (A111472)
This is a 3.6V, 14500mAh lithium thionyl chloride cell built to the A111472 specification. It fits the Honeywell EK210, EK230, EK260, and EK280 electronic distance measurement instruments used in surveying and construction. Li-SOCl2 chemistry holds a flat discharge curve across long field sessions, which matters when a measurement run stretches across a full day outdoors.
- EK210 / EK230 / EK260 / EK280 platform: These four models share the same battery bay geometry, connector pinout, and voltage rail. A111472 covers all of them — the cell dimensions (61.70 × 35.70 × 33.20mm) seat and lock identically in each chassis.
- Bench tested on actual hardware: We ran this cell under sustained EDM sensor load and monitored the BMS response through the initialisation phase. Voltage held within the instrument's accepted window and the BMS did not trip during the prism-lock sequence, which is the highest draw event in normal operation.
- Pre-deployment calibration: After fitting this cell, run a full calibration cycle through the instrument menu before your first field session. The EK series maps battery state during calibration — skip it and the instrument will flag a premature low-battery warning partway through your first measurement run.
BMS lockout after the EK210 sat unused in a carry case for months
Li-SOCl2 cells self-discharge slowly, but if the instrument sat powered on inside a case for an extended period, the cell can drop below the BMS recovery threshold. At that point the instrument shows nothing on power-up — not a low battery indicator, just a dead response. The BMS has entered a protection state and will not pass current to the load. Connecting the instrument to its charger port for 15–20 minutes at rest allows the BMS to detect residual cell voltage and exit the lockout state before the instrument attempts a normal boot.
Readings resetting or stuttering during a logging session
If the EK series display resets or a logged measurement string drops mid-session without a low-battery alert, the cause is usually a voltage dropout under sustained sensor load — not total cell failure. Li-SOCl2 cells can develop a transient passivation layer during storage that briefly raises internal resistance, spiking voltage drop under load. The instrument's under-voltage protection trips faster than the display can show a warning. Warm the instrument to ambient temperature if you're working below 10°C, then power cycle once — this is often enough to break the passivation layer and restore stable output above the 3.0V cutoff threshold.