Thaka.AiReviewed 16 October 2026 · schematic not to scale
Science Buddies documents a working zinc-air cell; its LED extension may require several cells. Use its tested electrode kit and complete method.
- 1Documented electrodes
- 2Open saltwater cells
- 3Polarity and loaded meter checks
- 4Matched LED; electrodes are consumed
Site and operating requirements
- Use only the project’s documented saltwater chemistry, electrodes and matched low-voltage load.
- Prepare a spill-resistant tray, eye protection and a labelled waste container; this experiment consumes electrode material.
Tools and measuring equipment
- Scale, graduated vessel, timer, correctly configured multimeter, clip leads and a matched LED/buzzer.
Output and operating conditions
No fixed lamp W is published. Measure voltage and current simultaneously under the LED load. Example arithmetic only: 2 V × 1 mA = 0.002 W.
Chemical cell consuming zinc; not renewable saltwater fuel. Electrode dimensions and lamp performance are not specified in the project.Parts, quantities and dimensions
| Part | Quantity | Specification / dimensions |
|---|---|---|
| Tested copper / zinc electrode kit | 3 pairs | Use the project kit, six clip leads, meter and matched red LED; do not guess electrode substitutions. |
| Open cups and electrolyte | 3 cups | About 240 mL cups; 25 g table salt in 500 mL water; 150 mL per cell. |
Preparation and component checks
- Label the three cups and electrode pairs. Prepare the documented 25 g salt / 500 mL water solution and measure 150 mL into each cup without bridging electrodes.
- Check cell polarity with the source’s test load before the LED extension. Keep clips above solution and disconnect before repositioning electrodes.
Procedure
- 1
Prepare the solution; secure separated copper and zinc electrodes in each open cup.
- 2
Check each cell with the matched buzzer, then follow the source LED extension and polarity instructions.
- 3
Record loaded V and I; do not multiply open-circuit voltage by short-circuit current.
Safety and inspection
Adult supervision, eye protection, open containers, no drinking, mains or sealed gas collection. Use the saltwater-only baseline; do not add bleach, acids or peroxide. Follow local disposal guidance.
Verify the result
If the LED stays dark, check polarity and the source’s series-cell guidance. It is an experiment, not an emergency-light guarantee.
Measurement log
- Solution recipe, wetted electrode area if known, cell count, LED polarity, simultaneous loaded V/A, duration and electrode corrosion.
Maintenance and repeat checks
- Disconnect, rinse and store electrodes as the kit directs. Keep solution labelled and follow local disposal instructions; never mix in cleaning chemicals.
Troubleshooting
- No output, abnormal heat, noise, vibration or leaks
- Stop and isolate first. Check the documented input, load compatibility, alignment and connections; keep guards fitted and refer specialist systems to their installer.