RAE Systems 029-3501-000 Compatible Battery 7.4V 1800mAh

RAE Systems RAE029-0695000 / RAELink 3 Series — 7.4V Li-ion Replacement Battery (029-3501-000)

This is a 7.4V, 1800mAh Li-ion replacement battery for RAE Systems multi-gas detectors and wireless transmitters. It fits the RAE029-0695000, RAELink 3 Mesh, RAELink 3 Mesh Radio, and RAELink 3 Wireless Transmitter. Capacity is 13.32Wh, matching the OEM spec from RAE Systems part number 029-3501-000.

• RAELink 3 and RAE029-0695000 compatibility: These models share the same 7.4V battery rail, connector footprint, and BMS handshake protocol. One cell pack services the full group — no adapter or modification needed.
• Bench tested on actual hardware: We ran this pack on a RAELink 3 Mesh unit and cycled through sensor initialisation and active RF transmission. The BMS held steady through the current spike at radio power-up and did not trip during sustained sensor polling.
• Post-install calibration cycle: After fitting this battery, run a full calibration cycle through the instrument menu before field deployment. The RAE Systems firmware maps battery state during calibration — skipping this step causes premature low-battery warnings during the first measurement session, even with a full charge.

BMS lockout after a RAELink 3 unit sat unused in a carry case for months

Li-ion cells in low-draw standby devices self-discharge slowly over months. If the pack voltage drops below roughly 2.5V per cell, the BMS trips into deep-discharge protection and the instrument will not power on or charge normally. This is not a dead battery — it is a protection state. Applying a charger at that point often shows no charge activity because the BMS is blocking current input. To recover the pack, connect it to a compatible charger for at least 30 minutes without interruption; some chargers require a trickle-charge wake cycle before full charge current resumes.

Readings drifting or logging session resetting mid-run

Under sustained sensor load — particularly when multiple gas sensors are actively polling — the battery voltage can sag below the instrument's stable-operation threshold without the low-battery indicator triggering first. The firmware interprets this momentary voltage dropout as a fault condition and resets the active logging session. This is not a sensor fault. Check the battery voltage under load using the instrument's diagnostic menu; if it reads below 6.8V during active sensor use, the cell capacity has degraded and the pack needs replacement.