ITRON Sparklog 3.6V Li-SOCl2 Compatible Battery 50103801

ITRON Sparklog 31-50-01.001 — 3.6V Li-SOCl2 Replacement Battery (50103801)

This 3.6V, 2600mAh Li-SOCl2 cell replaces OEM part 50103801 in the ITRON Sparklog 31-50-01.001, Sparklog GSM, and Sparklog analog data loggers. These loggers run in utility metering and industrial PLC environments where continuous SRAM retention and RTC accuracy are non-negotiable. Swap only with the controller powered on — removing this cell while the unit is off will wipe stored meter data and program memory instantly.

• Sparklog 31-50-01.001, GSM, and analog compatibility: All three Sparklog variants share the same 3.6V lithium thionyl chloride supply rail, connector pinout, and BMS handshake. One cell part number — 50103801 — covers all three. No adapter or modification needed.
• Bench tested on actual hardware: We ran the cell on the Sparklog platform and confirmed stable float charge acceptance, correct BMS recognition, and clean SRAM hold voltage across the full discharge curve. The cell met rated capacity at 2600mAh under controlled load.
• Hot-swap procedure for Sparklog loggers: Always replace this battery with the Sparklog powered on and actively logging. Li-SOCl2 cells provide no residual charge buffer once removed — SRAM loses retention in under a second with no supply present. If the swap was done with the unit off, a full program and configuration reload from the host system is required before resuming metering.

Why the Sparklog loses stored meter data during a battery swap

Li-SOCl2 cells have no meaningful residual voltage once the circuit is broken — unlike alkaline or NiMH cells, they drop to near zero the moment contact is lost. The Sparklog's SRAM holds meter readings and configuration only as long as supply voltage stays above the retention threshold, typically around 2.0V. Break that supply for even a fraction of a second with the main power off, and all stored data is gone. The only safe swap method is to keep the logger energised on its main supply throughout the cell change.

New cell installed but the Sparklog battery alarm is still active

Li-SOCl2 cells ship at a storage voltage slightly below their nominal 3.6V — this is normal passivation behaviour, not a fault. The Sparklog's battery alarm checks cell voltage at the moment of installation, and a freshly installed cell may still read low enough to hold the alarm flag. The alarm does not clear automatically once voltage recovers; it requires a manual reset through the host programming or configuration software. Confirm the cell reads at or above 3.5V at the terminal, then clear the alarm flag in software — it will not self-reset.