Calculator Centrum 80405 — portable solar plus button cell power, 116×75×18 mm

Centrum 80405 is a compact desktop calculator that combines a solar panel with a backup button cell to ensure continuous operation. Measuring 116×75×18 mm, it provides basic arithmetic functions in a slim, portable housing suitable for everyday use at home, in school, or in the office. The dual-power arrangement maintains functionality in varied lighting conditions and reduces interruptions during routine calculations.

Advantages

The calculator’s dual power source—solar with button cell backup—optimises reliability by switching to the battery when ambient light is insufficient. Its small footprint and low weight make it easy to carry between locations or store in a drawer. Large, tactile buttons and a clear numeric display support quick numeric entry and reduce input errors. The simple function set focuses on essential operations, allowing straightforward, predictable use without complex menus.

Suitable for

• Everyday arithmetic tasks at home
• School use for basic math exercises
• Office tasks such as quick sums and expense checks
• Portable needs where compact size and reliable power are important

Key specifications

• Dimensions: 116 × 75 × 18 mm
• Power source: solar panel with button cell backup
• Form factor: compact desktop calculator
• Primary functions: basic arithmetic (addition, subtraction, multiplication, division)
• Input: tactile numeric keypad
• Display: clear numeric LCD

How to use

Place the calculator on a stable surface in adequate light to prioritise solar power. Use the numeric keypad and function keys to enter numbers and perform calculations; results appear on the numeric LCD. When ambient light is low, the calculator will automatically use the internal button cell to maintain operation. Turn off or store the device in a shaded area if long periods of inactivity are expected to conserve the backup battery.

Usage recommendations

For consistent performance, keep the solar panel clean and free from scratches or adhesive residues, and replace the button cell when signs of dimming display or intermittent operation appear. Store the calculator at moderate temperatures and avoid prolonged exposure to direct sunlight to protect the case and internal components.