GUOER

Warm drinks in a hot car and cold lunches at midday are familiar small disappointments. GUOER approaches them with a Peltier element rather than ice packs or a compressor, letting a single 4L bag either chill or heat its contents depending on the mode selected.

Cooling and warming in one bag

According to the maker, GUOER covers a cooling range of 0–20℃ and a warming range of 40–70℃. A Peltier element cools one face and heats the other when current passes through it, and the bag uses this property to switch modes. The maker says it can lower the interior temperature by about 15℃ or more in a 30℃ room. It also notes that set temperatures are guidelines: actual results vary with room temperature, the amount of contents and their starting temperature, and the system is built for slow, stable temperature holding rather than rapid cooling or heating. Insulation is said to keep contents cold or warm for a while after power is cut.

Two ways to power it

The bag runs from USB or a car cigarette-lighter socket, and the maker says a car plug and a DC5521 to USB cable are included. A power bank can be used where no outlet is available. Performance depends on the source: the maker recommends a power bank with 9V/2A or higher output, or a 12V/3A home adapter or car socket, for the most stable results, and cautions that USB operation may perform slightly below the car socket.

Size, weight and noise

• Capacity: 4L, with interior dimensions of approximately 13×13×24cm
• Holds six 330ml cans, or a lunch box with a PET bottle, according to the maker
• Weight: 1.1kg, with a sturdy carry handle
• No compressor, which the maker says keeps operation very quiet
• Modest power consumption, per the maker

The tall, narrow interior is pitched at soup jars and coffee bottles as well as cans, and the maker positions the bag as small enough to sit on a desk or beside a car seat, or to pack in a backpack for camping and picnics.