Saft LS-17330 3.6V 2/3A Li‑SOCl2 Battery

The Saft LS-17330 is a compact, long-life primary lithium‑thionyl chloride cell designed for ultra‑low average current applications that need decade‑scale service life and reliable operation from -60°C to +85°C. Typical uses include utility meters, remote IoT sensors, asset trackers, and memory/RTC backup in industrial equipment and PLCs.

Key specs at a glance

Nominal voltage	3.6 V
Nominal capacity	≈2.1 Ah (at low load, 20°C)
Chemistry	Lithium–Thionyl Chloride (Li‑SOCl2), bobbin construction
Size	2/3 A (approx. Ø16.7 mm × 33.4 mm)
Weight	≈14–15 g
Operating temperature	-60°C to +85°C
Self‑discharge	≈1% per year at 20°C (typical)

When to choose the LS-17330

• Ultra‑low average current (microamps to low milliamps) with long standby life.
• Space‑constrained designs needing higher capacity than 1/2AA but smaller than AA.
• Cold‑chain, outdoor, or industrial environments down to -60°C and up to +85°C.
• Devices that sleep most of the time and wake to transmit or log data (e.g., AMR/AMI meters, remote sensors, GPS pings).

When to consider alternatives

• High continuous current or frequent heavy pulses: consider a pulse‑assist capacitor with the LS‑17330 or a high‑rate Li‑SOCl2 (spiral type) cell.
• Rechargeable requirement: choose Li‑ion/Li‑polymer or LiFePO4 rechargeable cells instead.
• Short runtime with high drain: a larger cell (e.g., AA LS‑14500) or multi‑cell pack may be more suitable.

Pulse loads: getting reliable starts

Bobbin Li‑SOCl2 cells provide excellent energy density but have limited instantaneous current. For radios and bursts (e.g., 50–300 mA), add a low‑ESR capacitor close to the load.

• Start with 47–220 µF low‑ESR electrolytic or 22–100 µF ceramic; size by measuring voltage droop during the worst‑case transmit event.
• Use short, low‑resistance wiring and consider a series resistor to limit inrush to the cell.
• Pre‑pulse warming (brief lighter load before TX) can reduce initial voltage delay in cold conditions.

Runtime planning (quick estimates)

Approximate service life = usable capacity / average current. Real‑world life is reduced by temperature, pulse profile, and passivation. Examples:

• 15 µA average sensor: 2.1 Ah / 0.000015 A ≈ 140,000 h ≈ 16 years; practical limit often 10–15 years due to self‑discharge and environment.
• 100 µA data logger: 2.1 Ah / 0.0001 A ≈ 21,000 h ≈ 2.4 years.
• Sleep 10 µA; hourly 20 mA for 2 s: average ≈ 10 µA + (20 mA × 2/3600) ≈ 21 µA → ≈ 11 years theoretical; validate with pulse‑assist capacitor.

Compatibility and replacements

• Also referenced by the IEC size code ER17330 (Li‑SOCl2, 17 mm × 33 mm class).
• Common in PLC/industrial memory‑backup packs; some assemblies add leads, tabs, or connectors—match voltage, chemistry, size, and termination.
• Do not substitute 3.0 V lithium manganese dioxide (CR series) cells; voltage and chemistry differ.

Handling, storage, and safety

• Primary cell—do not recharge, short‑circuit, crush, or incinerate.
• For soldering, use factory‑tabbed cells; avoid direct heat on the can to prevent seal damage.
• Store cool, dry, and ventilated; ideally ≤30°C in original packaging.
• Transport is subject to lithium battery regulations (UN3090/3091). Follow applicable packaging and labeling rules.
• Check the latest Saft datasheet for certifications, test conditions, and approved operating limits.

FAQ

Is the LS-17330 rechargeable?

No. It is a primary (non‑rechargeable) Li‑SOCl2 cell. Charging can cause leakage or venting.

What causes voltage delay/passivation, and how do I mitigate it?

Bobbin Li‑SOCl2 cells can form a passivation layer during storage, leading to a brief voltage dip under first load, especially when cold. Use a pulse‑assist capacitor, pre‑load the cell with a light current before heavy pulses, and validate at minimum temperature.

Can it power radios or cellular modems?

Yes, if the average current is very low and a suitable low‑ESR capacitor supplies the burst current. For frequent or long transmit bursts, a high‑rate cell may be better.

Is ER17330 the same as LS-17330?

ER17330 is a generic Li‑SOCl2 2/3A size designation. LS‑17330 is Saft’s model in that size. Always verify capacity, temperature rating, and terminals when cross‑referencing.

How does temperature affect capacity?

Available capacity and pulse performance decrease at low temperatures; internal resistance rises. Validate your load profile at the lowest expected temperature.