Gama Sonic 3.2 V 800 mAh LiFePO₄ (18500)

Overview

The Gama Sonic 3.2 V 800 mAh LiFePO4 (18500) is a rechargeable lithium iron phosphate cell designed for larger solar path lights, motion/security fixtures, and off-grid devices that specify a 3.2 V LiFePO4 battery in the 18×50 mm size. It delivers a steady voltage, long cycle life, and reliable performance in daily charge/discharge use.

Key Specs

• Chemistry: LiFePO4 (Lithium Iron Phosphate)
• Nominal voltage: 3.2 V (charge cutoff typically 3.6–3.65 V)
• Capacity: 800 mAh (0.8 Ah)
• Size: 18500 (≈18 mm diameter × 50 mm length)
• Cycle life: Typically 2,000+ cycles to ~80% capacity under proper use
• Self-discharge: Low (good for seasonal use)
• Terminals: Check your device for button-top vs flat-top requirements

When to Choose This Battery

• Use if: Your device explicitly calls for a 3.2 V LiFePO4 18500 cell (often found in higher-output solar lights, security lights, or off-grid sensors).
• Avoid if: The device expects a 3.7 V 18650 Li-ion, a 3.2 V 14430/14500 LiFePO4, or 1.2 V NiMH/alkaline cells—the size and voltage are different and not interchangeable.

Expected Runtime (Examples)

Actual runtime varies with LED brightness, temperature, and driver efficiency. As a quick guide:

• At ~50 mA draw: about 12–14 hours
• At ~100 mA draw: about 6–8 hours
• At ~200 mA draw: about 3–4 hours

Installation Steps

1. Confirm fit: Verify your device specifies 18500 size and LiFePO4 chemistry (3.2 V).
2. Match terminals: Check whether your device needs a button-top or flat-top cell.
3. Polarity: Align + and − as marked; do not force the cell into the compartment.
4. Single or multiple cells: If your device uses more than one cell, replace all cells together with identical type and capacity.
5. Initial charge: Allow a full sunny day for solar fixtures or precharge with a LiFePO4-compatible charger.

Charging & Care

• Charger type: Use only a LiFePO4 charger with a 3.6–3.65 V cutoff. Do not use standard 4.2 V Li-ion chargers.
• Charge rate: A gentle 0.2–0.5C (160–400 mA) is typical unless your device specifies otherwise.
• Avoid deep discharge: Repeatedly running below the device’s low-voltage cutoff shortens life.
• Storage: Store cool and dry at ~40–60% charge; check and top up every 3–6 months.
• Temperature: Typical charge 0–45°C; discharge −20–60°C. Performance drops in cold conditions.

Compatibility Notes

• 18500 vs 18650: 18500 is shorter (50 mm vs 65 mm). An 18500 will not substitute an 18650 without a specific adapter, and the chemistry/voltage may differ.
• Voltage matters: 3.2 V LiFePO4 is not a safe substitute for 3.7 V Li-ion or 1.2 V NiMH cells.
• Series packs: Devices using two LiFePO4 cells in series expect about 6.4 V nominal; replace both cells together.

Pros and Cons

• Pros: Long cycle life, stable 3.2 V output, safer chemistry, low self-discharge.
• Cons: Lower energy density than 3.7 V Li-ion; may show reduced output in very cold weather.

FAQ

Is this battery rechargeable?

Yes. It is a rechargeable LiFePO4 cell and must be charged with a LiFePO4-compatible charger or a device designed for LiFePO4 batteries.

Will this replace a 18650 battery?

No. 18650 cells are longer and usually 3.7 V Li-ion. This 18500 LiFePO4 cell is 3.2 V and shorter; they are not interchangeable.

My solar light originally used a 14430 or 14500—can I use this?

No. 14430/14500 cells are smaller. Use the size and chemistry specified by the manufacturer.

Can I mix old and new batteries?

Avoid mixing. For devices using multiple cells, replace all at the same time with identical type and capacity.

Do I need a button-top or flat-top?

Check your device’s contact design. Many solar lights require a button-top to ensure positive contact.