content: The benefits of user-replaceable batteries In portable electronics, the battery is the component with by far the shortest life expectancy, thus supposed to be modular and replaced like brakes and wheels on vehicles upon expiration. Over time, with normal usage, a rechargeable battery wears down and loses both capacity and performance. Each charging and discharging cycle adds to the weardown. On devices powered by Lithium-Ion batteries, the most common battery type in portable electronics, the battery performance's decline usually becomes noticeable after two years of normal usage or one year of heavy usage. Although the battery should have around 80% of its original performance at that point, it means that it is approximately at the middle of its lifespan. Power starvation	 At one point after enough usage, a battery is weakened by its age so much that the voltage risks falling below a threshold (e.g. 3.0 Volts for mobile phones) during normal operation, unexpectedly causing a poweroff. The battery is considered to have reached the end of its useful (functional) lifespan at that point. Due to the low performance of aged batteries, a device has to artificially limit its processing power to avoid overwhelming the age-weakened battery. Colder environmental temperatures that slow down the chemical reactions inside the battery and lower charging states decrease the output power limit even further. To prevent this power starvation effect, the device would have to be connected to an external power source such as a wall charger/power supply or a power bank, from where it should be able to draw power in abundance, provided that the power source works as intended. Battery weakness has especially been a historical problem on iPhones because their batteries had a low capacity to begin with. Because smaller and more aged batteries are weaker, powering the same tasks and charging at the same absolute speed induces more stress onto the battery cell due to higher power requiremnts relative to the battery's strength. Batteries with less than 10 Watt-hours are considerably too weak to power 2160p (4K) and high frame rate (e.g. 1080p@120fps, 720p@240fps) video recording anyway, thus will degrade quickly when used for powering such tasks. The usage of video recording modes on newer devices with even higher pixel rates, such as 2160p@60fps, 1080p@240fps, continuous 720p@480fps demand even more battery power. New resolutions such as 3240p 6K and especially 4320p 8K on devices such as the Samsung Galaxy S20 models demand ravenous battery power and produce significant heat. Knowing that one could easily and quickly replace the battery at any time is a liberating feeling.[note 1] In contrary, the thought of one trapped (non-modular) component with a short lifespan having the potential to render the entire device near-useless upon expiration could give the user inconvenient subconscious saliency. Fast charging speeds and full, deep charging cycles (i.e. charging a battery up to 100% and discharging down to 0%) reduce the life span of the battery faster. High charging currents relative to the battery size put enormous stress on the battery cell. The heat produced during fast charging speeds and high usage of the CPU and GPU further accelerates the wear & tearing of the battery. Heavy usage not only heats up the device but also drains the battery faster, speeding up consumption of the limited recharge cycles. This includes high resolution and/or framerate video recording and playback, 3D gaming, mobile video editing, high screen resolutions (e.g. 1440p), high refresh rates (e.g. 90 Hz, 120 Hz), video telephony and usage of cellular networks like 4G and especially 5G. To extend the life span of the battery and somewhat delay its inevitable demise, one would have to sacrifice convenience by keeping the battery charging state between approximately 25% and 75%, avoid excessive heat and deactivate the convenient fast charging feature (or limit charging speed by using less powerful chargers), which negatively affects the user experience. With a replaceable battery, one can blissfully charge fast, use full charging cycles and do power-intensive tasks such as high-resolution and/or framerate video recording, without bothering with battery care or feelings of guilt knowing that the limited battery lifespan would be a dead-end for the entire device upon expiration. A forced battery replacement of a sealed battery (i.e. battery surgery) by a mobile phone repair shop usually costs at least five times as much as a replacement battery, may take hours instead of less than two minutes, and possibly irreversibly damages the water resistance seal. In addition, instead of easily manually replacing the battery at home within a minute, one has to trust ones device to a repairman with the hope that he successfully performs the battery surgery without damaging any delicate parts of a device that was never built to ever have its battery replaced. Some vendors offer users a servce to deposit their device through (physical) mail for a replacement. In that case, the user has to trust that their posted device does not get lost or damaged anywhere in the delivery. In addition, users located in remote places and smaller valleys might have to wait days for their device to arrive back at home. Arguments in favour of non-user-replaceable mobile phone batteries debunked. Some devices, especially dedicated cameras and camcorders, but also many laptops, have an easily accessible battery compartment, which allows the instant replacement of a discgarged battery with a charged one. While the device operates on the charged battery, the discharged battery can be recharged using an external charger, to be immediately ready for usage as soon as the other battery is discharged again. This argument is less of a concern for mobile phones with fast charging technology, because they can be recharged very quickly anyway using powerbanks that support fast charging. In addition, some mobile phones with replaceable batteries have back covers that need to be opened using a screwdriver instead of by hand. Such devices include the Samsung Galaxy Xcover outdoor/rugged phone series. Although such back covers make the battery less accessible on the go, they can provide more reliable protection against water and dust ingress while still allowing the replacement of an expired battery (that has reached the end of its lifespan) within minutes at home. The argument “But I replace my phone every 1 to 2 years anyway!” does not change the fact that irreplaceable batteries are planned obsolescence by definition. One is also supposed to purchase a device out of appreciation for its functionality, not because one failing part that is hardly replaceable rendered the entire previous device near-useless and highly dependent on external power input (“wall hugging”). Many users prefer to keep using their device for well beyond 2 years because it could still fulfill its purpose and get its work done. But that device might not work as intended anymore due to battery failure. In addition, devices with locked bootloaders (which is the default state) have heavy restrictions on data portability. Battery cases, in a nutshell, are power banks in the form of phone cases. They provide electricity to the phone through an integrated charging plug or wireless charging. Although a creative idea and a useful accessory to many, battery cases are not useable in combination with other phone cases that have special features such as strong protection and an integrated horizontal kickstand.