Using macbook USB charger for android tablets and phones I am looking into finding a USB OTG cable/adapter that allows me to connect USB peripherals to an Android tablet while charging it. Ultimate goal is to get the power from a car's cigarette lighter (possibly using a USB adapter which provides 5A/3.0A or 2.4A)

While researching, I found out there are number of issues including, not all devices truly support this mode. (I heard most samsung devices do. Anyway to find a certain device supports this, before buying?) And certain adapters have a physical switch and doesn't really support simultaneous charging and data transfer/USB hub mode.

I am wondering if I can use the adapters that claim to charge and act as a hub for the Macbook, which has a single USB C port.

Lot of these adapters (designed for Macbook and Chromebook pixel) provide 14.5V/2.0A which makes me worried, as my phone charger only provide 5V/3.0A (Nexus 5X which has quick charging).

Is it possible to connect a phone or tablet to one of these adapters and not get damaged by the extra power? And would the adapters work under the power of the car cigarette lighter which only provide 5A/3.0A, when they possibly expect 14.5V/2A from a macbook charger instead?
Fundamental thing is that you are contemplating laptop chargers , designed for much bigger capacity batteries to charge your cell and then plan to use the car charging, in between- not a healthy combination and recipe for problems


  Anyway to find a certain device supports this, before buying?


No proven way AFAIK...you would need to research product and user reviews and ask around in device specific forums or write to manufacturer


  Is it possible to connect a phone or tablet to one of these adapters and not get damaged by the extra power?



You would not get fast charging for sure
Chances of damage are high mainly due to high voltage levels - for details , see How do I select a non-OEM charger for my device?



  And would the adapters work under the power of the car cigarette lighter which only provide 5A/3.0A, when they possibly expect 14.5V/2A from a macbook charger instead?


Unlikely that they would work