Mini peltier dehumidifier teardown.

These little dehumidifiers are widely available under several brand names and with wildly varying prices for the exact same units.
They are usually described as 300ml or 500ml dehumidifiers although that does not in any way relate to their daily extraction performance. In short these work for very small spaces, but are not as efficient as traditional compressor or desiccant drum dehumidifiers. If you buy one to keep a room dry you may be disappointed, but for a small portacabin or camper they may actually be a viable option.
They're very quiet due to the only moving part being a computer style fan. The two main components, the fan and peltier array both operate directly on 12V so it's actually viable to run one of these from a small solar panel. Note that the operating current is 3A.
The main failure modes of these things are probably the fan bearing going noisy due to it's low cost and the power supply failing due to the relatively heavy load of 3A at 12V and inevitable cost cutting.
The design is very similar to the little mini-fridges you get that can run from a cigarette lighter socket in a car. Theoretically you could use one of these dehumidifiers in a car, but the battery load of 3A is quite high for continuous operation.
The internal construction is ultra simple. A peltier array is sandwiched between two heatsinks. A small smooth one on the cold side that condenses water vapour out of the air that is pulled in across it, and a larger heatsink on the hot side that the air then passes to keep it cool.