Motor revolutions
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.
Battery type
— 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.
Operating time
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.
Charging time
Charging time for the electric shaver battery from a fully discharged state to 100% charge. If freedom of movement when shaving is most important to you in a cordless shaver, and you always have access to the power supply (for example, you rarely travel), this parameter does not matter much. However, if you often travel on trips in which you have to constantly move from place to place, you should pay attention to
models with a short charging time.
Voltage switching
The ability to switch the voltage for which the shaver is designed, adjusting it to the characteristics of various electrical networks. This feature is useful for those who often travel abroad: in different countries, the voltage in the outlet can also be different. For example, in Europe and most Asian countries, 230 V networks are used, but in North America the voltage is 110 V.
In the simplest models with this function, the voltage is switched manually, more advanced shavers have an automatic network adjustment system.
