Solstice — Solar-Charging Flask

Sunlight is the power supply.

A ring of thin-film solar cells wraps the cap. In good, steady light it trickle-charges the cap's sealed cell so you can top up a phone, earbuds or a headlamp — think a short rescue charge, not a full refill. How much it gathers depends on the light the cap actually receives.

Below the cap it is a straightforward vacuum flask — 24 hours cold, 12 hours hot — because a bottle should be a bottle first.

Realistic performance. The solar cell is a small supplemental charger: on a bright desk or windowsill it may add enough for a brief top-up over a day; in low light or cloud it adds little. It outputs 5 V up to 1 A over USB-C and can also be topped up from the wall. It will not fully recharge a modern phone.

Why it's different

• Thin-film solar ring in the cap; sealed storage cell
• USB-C port on the cap — charge out or top up from the wall
• Vacuum insulated: 24 h cold / 12 h hot
• No app, no pairing; charges whatever is plugged in

Specification

In the box

• Solstice flask
• USB-C cable
• Care card

Care. Hand wash the body. Wipe the cap with a dry cloth — never submerge it.