Review: Logitech Signature Slim Solar+

On September 24, 2025, Logitech introduced a new keyboard. While senses.se has reviewed numerous keyboards, this marks our first hands-on experience with a truly cord-free model. We emphasize ‘cord-free,’ as the Logitech Signature Slim Solar+ features no physical charging port, which offers a distinctive user experience. Most core functionalities are present, with minor exceptions. Nevertheless, it represents a significant step in sustainable product design, albeit with some areas for further refinement.

Building on Prior Solar Innovations

To provide context, we must revisit a product launched approximately 15 years ago: the Logitech K750 Wireless Solar Keyboard. This keyboard utilized solar cells for power and could operate for up to three months in complete darkness. While Logitech has explored solar charging before, this is their first product to explicitly state that artificial light sources are sufficient for charging (though anecdotal evidence suggests the K750 may also have benefited from artificial light). Naturally, the Logitech Signature Slim Solar+ boasts enhanced features, greater efficiency, and improved durability compared to its predecessor (e.g., the K750 famously required a cleaning cloth for its solar cells). However, there are one or two features present in the K750 that we find absent in the Logitech Signature Slim Solar+, which we will discuss later.

Package Contents

The package contents are minimal, reflecting the product’s streamlined concept. Users will find the keyboard itself and a Logi Bolt dongle, with no additional accessories.

Initial Impressions: Logitech Signature Slim Solar+

Logitech’s Signature series shares functional similarities with the MX series but presents a less premium aesthetic. The keys exhibit a more pronounced auditory feedback, the unit has less perceived weight, and the overall construction feels somewhat more tactile (plasticky) in comparison. However, in terms of functionality, it delivers largely the same feature set, including device-switching keys configurable within Logitech Options+. Despite the slightly louder keypresses, the typing experience is comparable in comfort to models such as the MX Keys S. A notable absence, however, is key backlighting. Ultimately, the keyboard offers a comfortable and efficient typing experience.

The primary distinguishing feature of the Signature Slim Solar+ is the prominent solar (or light) cell positioned above the keys, serving as the keyboard’s exclusive power source. This area is dedicated solely to energy collection and does not function as a storage slot for accessories like the Logitech Crayon.

Cord-Free Operation: A Solution for IT Professionals

Our recent review of the Suunto Vertical Solar Canyon highlights two compelling parallels with the Signature Slim Solar+: both devices integrate solar cells and offer exceptional battery longevity. Beyond their distinct product categories (a fitness watch versus a keyboard), the Signature Slim Solar+ stands out by drawing power efficiently from all light sources—be it sunlight, a desk lamp, or office fluorescent lighting. This broad light source compatibility is a notable advantage that other solar-charging devices, including Suunto’s, could benefit from. Given that keyboards are typically unobstructed during use, the Signature Slim Solar+ maintains a continuous charge. Logitech optimistically estimates a four-month operating life even if the keyboard remains in complete darkness.

After approximately two weeks of consistent use, without any conscious effort to expose it to specific light sources, the battery level consistently registered at 100 percent. This performance is quite impressive, suggesting that the four-month darkness estimate may be entirely realistic. This effectively positions the Signature Slim Solar+ as a truly autonomous peripheral: it simply functions without requiring user intervention for power management. There are no low-charge warnings or physical cables to manage. Connectivity is established via either Bluetooth or a Logi Bolt receiver, allowing seamless integration with existing Logitech ecosystems.

Users can monitor the ambient light levels sufficient for charging through Logi Options+, though we note a point of critique here. We were unable to find an option to create a shortcut for this status check; instead, users must navigate through the application, select the specific product, and then activate the function. Considering this is a primary and central feature for a solar-powered keyboard, a dedicated physical button for this function would be highly beneficial, similar to the one found on the Logitech K750 Wireless Solar Keyboard.

Returning to the K750, Logitech previously offered an ingenious ‘Logitech Solar App’ that provided detailed information on charging efficiency. While perhaps not strictly essential (and requiring a download, as no CD-ROM was included), this feature was a thoughtful addition. We believe a similar dedicated monitoring application would be a valuable inclusion for the Signature Slim Solar+.

Enhanced Function Keys

Logitech has integrated several pre-programmed buttons with new functionalities, including AI shortcuts that allow users to select their preferred artificial intelligence service (with some pre-configured options). This button, along with several other customizable keys, can be assigned additional user-defined functions, enhancing productivity.

Conclusion: Logitech Signature Slim Solar+

Logitech states that the Signature Slim Solar+ is designed for a ten-year lifespan. While this is a compelling marketing claim and challenging to verify in a review setting, it’s rare for a keyboard to remain in active use for a full decade (the exceptional Logitech K740, distinct from the K750, being a potential exception). As Logitech itself has demonstrated, technological advancements inevitably lead to the obsolescence of older peripherals.

Nevertheless, the comprehensive design philosophy is commendable: a projected ten-year lifespan, battery autonomy for four months in complete darkness, and entirely cable-free operation. All essential functionalities are integrated, including multi-device switching for up to three peripherals. The sole notable omission is key backlighting. Priced at 1,400 SEK, it sits approximately 100 SEK above the MX Keys S, and this pricing is perhaps our primary point of contention. We believe a price point closer to 1,000 SEK would more accurately reflect its value proposition.

In summary, despite its price, the Logitech Signature Slim Solar+ earns a commendable rating, primarily due to its projected lifespan, operational simplicity, and robust functionality. It is an ideal keyboard for office environments, offering a typing experience very similar to that of the MX Keys S. We are confident that Logitech is pioneering a genuinely innovative and comprehensive approach to sustainability with this product.

Logitech provided review samples for this evaluation. Our editorial independence is paramount; material providers have no influence on our reviews, which are always written with the interests of our readers and consumers in mind.