I pulled an Inspiron 5559 out of the closest and plugged it in and got a warning that I had attached a 45 watt (Dell branded) power supply and that the battery would not charge under full load without a 65 watt or greater power supply (the battery does charge). I looked and found another Dell branded power supply but it did not fit my power port (I have 3 Dell's - XPS 13, Inspiron 5568 and Inspiron 5559). I bought the 5559 on used on ebay.com and may have gotten it without a Dell branded AC adapter.
The WARNING page has a [Continue] button. But pressing the continue button only goes back to the same warning page about a 45 watt power supply.
Request #1 - get a Dell Inspiron 5559 and plug in a 45 watt power supply and try to fix the bug that doesn't let the user continue after getting what it says is only a warning, not an error.
Also, the Warning screen says that the warning can be disabled in the BIOS. I looked through the BIOS and could not find any place to change the warning.
Request #2 - put the exact location in the BIOS setup where the "too low wattage AC adapter" warning can be disabled.
I went and did a query at dell.com for "Dell Inspiron 5559 power adapter", "Dell Inspiron 5559 power supply" and "Dell Inspiron 5559 power cord". Neither one returned anything that looked like it was a 65 watt AC adapter for a Dell Inspiron - there is a 45 watt power supply that comes up: Dell 45-Watt 3-Prong AC Adapter with 3-ft US Power Cord for Select Dell XPS / Inspiron Laptops.
Request #3 - stock, and/or make searchable, a replacement power supply (power adapter) for the Dell Inspiron 5559.
Although, they do sell 3rd party AC adapters with a listed compatibility with a 5559 on ebay.com.