Efento NB-IoT Compatible Battery 3.6V 6300mAh Li-SOCl2

Efento NB-IoT — 3.6V Li-SOCl2 Replacement Battery (ER14505M-1S3P-EFE04)

This is a 3.6V, 6300mAh lithium-thionyl chloride battery pack for Efento NB-IoT wireless sensor devices. It replaces the original ER14505M-1S3P-EFE04 pack in Efento's NB-IoT monitoring nodes used for industrial and environmental data logging. Capacity data is taken from product specifications — 22.68Wh total energy.

• NB-IoT sensor platform fit: Efento's NB-IoT nodes run on a 3.6V rail with a passive BMS that tolerates the low self-discharge curve of Li-SOCl2 chemistry. This pack matches that voltage rail and the 1S3P cell configuration the original uses, so the BMS reads the new pack without a handshake error on boot.
• Bench tested on actual hardware: We ran this pack through cold-start sensor initialisation and sustained NB-IoT transmission bursts. The BMS held stable across the inrush current spikes at radio wake-up events and did not trigger a cutoff during repeated transmission cycles.
• First deployment after installation: After fitting this pack, allow the device to complete at least one full NB-IoT registration and data-push cycle before leaving it unattended in the field. The sensor maps battery state during that first active session, and skipping it causes the low-battery flag to trip early — before actual depletion — on the first logging run.

BMS lockout after an Efento NB-IoT node sat unused in a case for months

Li-SOCl2 cells self-discharge slowly, but the BMS protection circuit can drop into sleep mode if the pack voltage falls below its recovery threshold during extended storage. When this happens, the node powers on briefly then cuts out, or shows no response at all. The fix is to apply a trickle stimulus — connect the node to its USB config port for 10–15 minutes without powering on, which allows the BMS to detect load and exit sleep mode. If the pack voltage has dropped below 3.0V, the BMS will not recover and the pack needs replacement.

Readings resetting or dropping out mid-logging session

This is not the same as a low-battery shutdown — the device stays on, but logged values reset or show gaps. The cause is a brief voltage dropout under the combined load of sensor sampling and NB-IoT transmission firing simultaneously. At that moment, supply voltage dips below the sensor module's operating floor, forcing a soft reset of the measurement circuit. Check the node's log for timestamps where the dropout occurred and compare against transmission intervals. If the pattern is regular, the existing pack's internal resistance has risen — a fresh pack at full capacity will hold the voltage rail steady through that combined draw.