2/3 AA Batteries

2/3 AA Batteries: How to Choose the Right Cell

2/3 AA (approx. 14.5 mm diameter × 33–34 mm length) offers AA-class diameter in a shorter package. You’ll find several chemistries: 3.6V lithium thionyl chloride (Li‑SOCl2, ER14335), 3.0V lithium manganese dioxide (Li‑MnO2, CR14335), 1.2V rechargeable NiMH, and less-common 1.5V alkaline. Typical capacities range from about 300 to 1700 mAh, depending on chemistry and load.

When to use 2/3 AA

• Long-life, low-drain sensors and meters where years of standby are needed (Li‑SOCl2).
• Wireless sensors and trackers that need strong pulse current without recharging (Li‑MnO2, often with a pulse-support capacitor).
• Devices that are recharged frequently or draw higher continuous/pulse current (NiMH).
• Budget, low-priority devices with modest runtime needs (alkaline; limited availability).

Quick Chemistry Comparison

How to Choose

1. Match voltage and chemistry: Use what your device specifies. 3.6V (Li‑SOCl2) is not a drop-in for 3.0V (Li‑MnO2) unless the device is rated for it. NiMH (1.2V) usually requires series cells in holders designed for it.
2. Size and terminals: 2/3 AA is ~33–34 mm long. Confirm space, button-top vs flat-top, and whether you need solder tabs or a holder.
3. Load profile: For ultra‑low average current (µA-range), choose Li‑SOCl2. For frequent or high pulse current (tens to hundreds of mA), Li‑MnO2 or NiMH is safer; add a pulse capacitor for primary lithium where needed.
4. Environment: For cold/heat extremes, lithium chemistries outperform alkaline and NiMH. Check the data sheet for the exact operating range.
5. Total cost of ownership: NiMH wins for frequent cycling; primary lithium wins for multi‑year standby with minimal maintenance.

Runtime Examples (Estimates)

• Remote sensor (30 µA avg) with 1,600 mAh Li‑SOCl2: 1600 mAh / 0.03 mA ≈ 53,000 h ≈ 6.1 years (allow for self‑discharge and temperature; plan for ~5+ years).
• Asset tracker with 1 s, 300 mA bursts every 60 s; 10 mA idle: Avg current ≈ (300 mA×1/60) + 10 mA = 15 mA. With 950 mAh Li‑MnO2, ideal runtime ≈ 63 h (~2–3 days). A pulse cap helps maintain voltage during bursts.
• Rechargeable device averaging 1.7 mA: 650 mAh NiMH / 1.7 mA ≈ 382 h (~16 days) per charge. Expect shorter runtime at low temperatures.

Safety and Handling

• Never charge primary lithium or alkaline cells.
• Do not short, crush, or expose to >60°C; use protective holders and avoid loose storage with metal objects.
• For soldering, order cells with factory tabs; do not apply a soldering iron directly to a bare cell.
• Transport: spare lithium metal cells are generally allowed in carry‑on only (not checked). Tape terminals and follow airline/shipper rules.
• Recycle used batteries at approved drop‑off locations; do not dispose in fire or household trash.

Compatibility Notes

• Also referenced as 2/3AA, 14335 form factor.
• Common part families: ER14335 (3.6V Li‑SOCl2), CR14335 (3.0V Li‑MnO2), 2/3 AA NiMH (often HR14335/KR14335).
• Not interchangeable with AA, CR123A, or 14500 cells—dimensions and voltages differ.

FAQ