Comparison Braun Series 3 3010s vs Panasonic ES-RT37

— Built-in trimmer. Device for trimming the contours of facial hair. A trimmer is similar to a clipper, but smaller and better suited for fine work. Located directly on the body of the device.

— Blade for hair cutting. Removable version of the trimmer (read more about the trimmer above), made in the form of a replaceable nozzle and is installed instead of the main nozzle with shaving heads. Thanks to this, the trimmer can be made wider than the built-in trimmer, and overall more efficient.

— Nozzle for ears and nose. The cylindrical nozzle of small diameter allows you to penetrate the inlet and ear and remove unwanted vegetation from there. It is installed mainly on top of the main nozzle.

— Universal comb. Such a nozzle can be useful for regular care of the stubble or beard, when you need to trim, shorten, and not just shave. Length adjustment allows you to select the desired value for a particular area or depending on the image and type of "hairstyle".

The speed of rotation of the electric motor of the shaver. A higher rotational speed (ceteris paribus) usually means a higher speed of movement of the blades, which has a positive effect on the closeness of the shave.

Model of replacement head(s) compatible with electric shaver. This data will be useful primarily when looking for spare nozzles.

— Li-Ion. Currently, the prevailing battery type is Lithium-ion (Li-Ion), known for its high energy density, compact size, and light weight. Li-Ion batteries offer approximately 400 charge-discharge cycles on average. These batteries exhibit minimal self-discharge and lack a significant "memory effect" (capacity reduction due to charging a partially drained battery). However, they are sensitive to cold temperatures and require high-quality charging currents.

— Li-pol. Lithium-polymer (Li-Pol) batteries maintain stable output voltage even during significant discharge. These batteries offer an average lifespan of about 800 charge-discharge cycles. Unlike some battery types, Li-Pol batteries don't exhibit a memory effect, and they operate reliably within a wide temperature range of -20 to +40°C. However, they are sensitive to deep discharge and overcharging. To address this, specialized chargers employing suitable power supply algorithms for the lithium polymer context are recommended for maintenance.

— Ni-Mh. Nickel-metal hydride (Ni-MH) batteries excel in managing substantial charge and discharge currents, making them suitable for power-demanding electric motors and rapid charging. These batteries now boast impressive longevity, enduring around 1000 to 1500 charge-discharge cycles, while maintaining an eco-friendly nature. In comparison to Li-Ion, Ni-MH batteries appear bulkier and add weight to the device, yet they offer a more economical option.

While higher battery capacity theoretically extends a device's operation on a single charge, practical considerations are more complex. Ampere-hours are a specific unit, comparable only among batteries with the same voltage. For differing voltages, capacity must be converted to watt-hours for accurate comparison. Furthermore, actual tool battery life depends on consumption and performance, not just battery properties. Comparing battery capacity is meaningful only when models share the same voltage and capabilities. Operating time is a more informative parameter for comparison.

The average runtime of electric shavers on a full battery charge, without recharging, is generally overestimated due to factors like hair length, density, and trimmer usage. Manufacturer claims for runtime tend to be higher than actual usage. Longer runtimes require heavier and more expensive powerful batteries. Most shavers offer around 45 minutes of runtime, while some models provide up to 1 hour or as low as 30 minutes of operation.