Tadiran SL-350PT Lithium battery 1/2 AA with 3.6 V and 1.2 Ah, with pins +1/-2

The Tadiran SL-350PT is a specialised primary battery based on lithium thionyl chloride ($Li-SOCl_{2}$), which is known for its extreme longevity and reliability. With its compact 1/2 AA design and a nominal voltage of 3.6 V it is the standard solution for industrial applications that require a constant power supply over many years with minimal self-discharge.

This specific version has 3 PCB contacts (pins) in the configuration +1 / -2. This means that it has a positive pin on one side and two negative pins on the other side. This arrangement ensures reverse polarity protection and mechanically extremely stable mounting directly on the circuit board (PCB).

Highlights at a glance

• Enormous energy density: Despite its small size, offers a capacity of 1.2 Ah, ideal for long-life electronic components.
• Extreme shelf life: Thanks to minimal self-discharge (less than 1% per year at room temperature), a service life of up to 10-20 years possible.
• Wide temperature range: Works reliably under extreme conditions from -55°C to +85°C, which makes them ideal for outdoor applications.
• Stable discharge voltage: The voltage remains almost constant at a high level over almost the entire discharge time.
• Safe PCB mounting: The 3-pin configuration (+1/-2) enables vibration-proof soldering on boards and prevents assembly errors.
• Hermetically sealed: The housing is laser-sealed to prevent leakage and to protect the sensitive chemistry from environmental influences.

Areas of application

• Industrial controls (PLC)
  • Used as a backup battery for data backup (RAM/RTC) in control systems from Siemens, ABB or Fanuc.
• Consumption meter (Metering)
  • Used in smart gas, water, or electricity meters that must operate for more than a decade without battery replacement.
• Safety technology
  • Power supply for sensors, alarm systems, and surveillance devices in remote or difficult-to-access areas.

Assembly & safety instructions

• Soldering process
  • When soldering to the PCB, the heat exposure should be kept as short as possible (max. 5 seconds at 260°C) to avoid damaging the internal seals of the battery.
• No recharge
  • This is a primary battery. Attempting to charge it may result in explosions, fires, or the release of toxic gases.
• Storage
  • Store the batteries in a cool and dry place. Avoid contact between the pins themselves or with conductive surfaces to prevent short circuits.

Features

FAQs about the Tadiran SL-350PT

Why does the battery have two negative pins?

For mechanical stability and reverse polarity protection. The two negative pins, together with the offset positive pin, form a triangular pattern on the PCB. This ensures that the battery can only be inserted in one direction, and it remains firmly in place even in case of vibrations.

Can I replace the SL-350PT with a standard 1/2 AA battery?

Only if the pin configuration is identical. There are 1/2 AA batteries with axial wires, simple solder tags or flat terminals. The replacement must have the grid dimensions and the pin layout of the SL-350PT (+1/-2) for fitting on the PCB.

What does the "passivation effect" mean?