Juniper Archer 14849 Replacement Battery 3.7V 3600mAh

Juniper Archer / Archer 2 Field PC — 3.7V Li-ion Replacement Battery (14849)

This is a 3.7V 3600mAh Li-ion battery for the Juniper Archer and Archer 2 handheld field computers. It fits the Archer Field PC and Archer Handheld Field PC lines used in GPS/GNSS data collection and geospatial surveying. Voltage and capacity match OEM specification 14849 exactly.

• Archer and Archer 2 platform fit: Both generations share the same battery bay geometry, contact pitch, and BMS handshake protocol. The cell voltage rail and connector pinout are identical across the Archer Field PC variants, so one pack covers the full lineup without modification.
• Bench tested on actual hardware: We cycled this pack through the Archer's charge management circuit and confirmed the BMS accepted charge termination correctly. The protection circuit responded to simulated sensor load spikes without tripping into lockout under normal operating draw.
• First-deployment calibration step: After fitting this pack, run a full calibration cycle through the Archer's system menu before going into the field. The device maps battery state during that cycle. Skip it, and the fuel gauge has no reference point — you will see premature low-battery alerts on the first survey session even with a fully charged pack.

BMS lockout after the Archer sat unused in a carry case for months

Li-ion cells self-discharge slowly in storage. If the Archer was shelved with a partially depleted pack, the cell voltage can drop below 2.5V — the threshold where the BMS enters sleep mode to prevent damage. At that point, the device will not power on and the charger may show no activity. To recover, connect to a charger and leave it for 20–40 minutes without interruption. Most BMS circuits will accept a trickle current and pull the cell back above the 3.0V recovery threshold before switching to normal charge mode.

Archer shuts down mid-logging session with sensor load active

When the Archer is actively logging GPS/GNSS data and powering a connected sensor module simultaneously, sustained current draw can cause momentary voltage dropout across the cell. If the voltage dips below the BMS low-voltage cutoff — typically around 3.0V under load — the unit shuts down even though the resting voltage looks fine. An aged or cold cell with higher internal resistance is the usual cause. Swap to a fresh pack and confirm resting voltage reads at or above 3.7V before deploying.