(1) The battery can get extremely hot from use and therefore can be a potential issur derabanon or d’Orisah (depending on the posaik) of making a fire. (2)  Making an LED lamp brighter from touching the screen is similar to making a fire brighter -Mavir.

• Fact: (1) The battery getting hot from usage is not a problem for two reasons (a) it does not happen from any single action that a user directly does, rather from an accumulation of acts or length of time – and none of which make it heat up directly from that use, which makes it a safeik. (b) the user does not want the battery to get hot, this is “lo nicha lei”. So the battery getting hot is a safeik pesik resha delo nichah lei, this according to all pokim is permissible.

• Fact: (2) Adjusting the LED backlight by touching the screen is not a problem of Mavir as the LED runs cold, meaning the actual LED source of light is cold (this is complex because sometimes one can feel an LED bulb and it will feel warm, however, the warm that one feels is not from the actual LED but rather from the inefficiency of the semiconductor processes that generate light) unlike an incandescent bulb where the actual filament burns and that produces the light.

Misconceptions of Muktzah (prohibition of moving/using)

(1) A smartphone has no permissible use on Shabbos and therefore is a “kli shemachto l’issur” and therefore is muktzah. (2) A smartphone is an expensive item and therefore is “muktzah machmas chisaron kis”.

• Fact: (1) A standard smartphone which is not running the Shabbos App would indeed be muktzah as there is no use for it on Shabbos and it is used for prohibited uses. However, with the Shabbos App enabled the phone is now usable on Shabbos on therefore is not muktzah.

• Fact: (2) A smartphone with the Shabbos App enabled is not “muktzah machmas chisaron kis” because a phone is something constantly used and not reserved for a special use.

Misconception of Boneh (building)  Soser (Breaking),  Molid (creating) and Ma’keh bepatish (Finalizing a product):

(1) Making an LED lamp brighter from touching the screen it is like creating a new fire which is Molid according to Schmelkes’ view of molid and (2)  Boneh and Soser according to the Chazon Ish as you are building/breaking a circuit and building/breaking the device to work/stop working. (3) Making a device work is Ma’keh bepatish.

• Fact:  (1) Adjusting the LED backlight by touching the screen is not Molid as the lamp is already on, Molid can only exist when you introduce and create something new.

• Fact: (2) It is not  boneh or soser, as boneh and sose as that would  only apply to making a circuit and breaking a circuit using a physical switch, neither of which apply here. Additionally, one is not making or breaking the device functionality, as it is already functioning.

• Fact: (3) Ma’keh bepatish can only apply when you do something that makes the device “come to life” if the device is already on and functioning it can not be Ma’keh bepatish.

Misconception of Uvdeh d’chol:

Using a phone is a weekday like activity – “uvdah d’chol” and is therefore assur.

• Fact: This is wrong for a few reasons (a) There are many electrical devices we use that are used in same way as the week on shabbos such as a fridge, freezer, hot water urn, warming drawers, hot plate, etc. (b) If one uses the phone in a different manner than during the weekday it is not doing the same thing as one does during the week. (c) using the phone on Shabbos to connect with friends and relieves stress as to the whereabouts of kids and elderly parents enhances the Shabbos.

To learn more about use of electrical items on Shabbos we recommend reading The Use Of Electricity On Shabbat And Yom Tov by Rabbi Michael Broyde and Rabbi Howard Jachter.