4V 1Ah Sealed Lead Acid (SLA) Rechargeable Battery for Handheld Flashlights and DIY Projects

Technical Details

• Dimensions: Approx. 30mm x 22mm x 65mm (Standard 4V 1Ah footprint)

• Standard Charge Current: 100mA (0.1C)

• Max Charge Voltage: 4.8V

• Cycle Life: 200–300 Charge/Discharge cycles

• Operating Temperature: -10°C to +50°C

• Weight: Approx. 80g to 100g

Prototyping and Engineering Tips from Robogears

• Charging Requirements: To avoid "gassing" or swelling the casing, do not charge this battery with a standard 5V USB power supply directly. Use a regulated charging circuit set to a maximum of 4.5V–4.6V. A constant current of 100mA is recommended for a healthy, slow charge.

• LED Flashlight Builds: This battery is the perfect voltage for 0.5W or 1W "Straw Hat" LEDs. Because the battery voltage (4V) is so close to the LED forward voltage (~3.2V), you only need a small 4.7\Omega$ to 10\Omega$ resistor to limit current, making the circuit very efficient.

• Deep Discharge Warning: Lead-acid batteries do not like being "run dry." If the voltage drops below 3.5V, charge it immediately. Leaving it at 0V for even a few days can cause "sulfation," which permanently reduces the battery's capacity.

• Soldering Leads: When attaching wires to the tabs, use a hot iron and work quickly (under 3 seconds). Excessive heat conducted through the terminals can damage the internal lead-to-plate seals and lead to premature failure.

Package Includes

• 1 x 4V 1Ah Sealed Lead Acid (SLA) Rechargeable Battery

Disclaimer

Images are for reference; actual dimensions or casing color may vary by batch. Specifications subject to change by manufacturer. This product contains lead; please dispose of it responsibly at an e-waste or battery recycling center.