Repairing a Kopriso Nixie Watch (2026)

Context

This page documents the repair of a Mi Esposita solar-powered Nixie watch following water ingress during outdoor charging. While the enclosure survived largely unmarked, moisture ingress discharged and damaged the internal LiPo battery pack.

The repair focused on validating the electronics independently, restoring functionality, and confirming long-term behaviour without altering the original design intent.

Initial inspection

Electronic watch movement removed for initial inspection.

Water damage

Visible traces of water damage.

Battery failure

Puffed batteries snapped the solar panel connection.

Disassembly

Solar panel removed.

Battery removal

Damaged battery pack removed.

Cleaning

All components cleaned thoroughly.

Functional test

Trial functionality test using a 0.47 F supercapacitor.

Artificial charging

Charging the supercapacitor using artificial light.

Validation

Watch running solely from supercapacitor energy.

Battery selection

Selection of new-old-stock batteries.

Charge testing

Charge testing to identify closely matched cells.

Reassembly

Movement reassembled with new batteries and solar panel.

Cosmetic work

Polishing of panels and Nixie tube.

Final assembly

Movement fitted back into the enclosure.

Automatic discharge test

Automatic battery draining mode.

Low-energy behaviour

Automatic mode disabled; faint manual display still possible.

Comparative charging

Charging repaired watch alongside a reference unit.

Charge completion

Full charge after 111 hours; reference unit completed in 118 hours.

Result

Repaired watch, fully operational.