30 or 15 amp

[Sprinter 1 cup]

Wire purchased from Napkins ,closed now.
But when flossing down I brought red and black wire meters of it.
Question is how do I tell what ampampage is it?

Also have data cable that's been in the garden/sun, is thi good for USB charging ports plus other 5 volt outlets,ports?
TIA

 

[wildebus]

1. Cut a length off and count the strands and post up how many there are (precisely - not a "about ....") to be sure. there are common standards for this.
From the picture (the cable with the cut and twisted ends?) it looks like 1mm2 cable, so ok for 15A but not 30A

2. Cable gauge used for data is usually very thin and carries very low current. I would not use it for any significant current carrying use. Just because something is low voltage does not mean you can use thin wire for it. In fact quite the reverse (for example, I have 70mm2 (12V) cable going into my Multiplus inverter and 2.5mm2 (240V) cable going out).
And if it has been lying in the sun and weather for any length of time it is scrap anyway. Bin it!

 

[xsilvergs]

I find this quite useful as it gives current rating for different conditions (like the amount of cooling). Not many consider that a wire buried in the middle of a loom can't dissipate much heat, something we always had to considered in aircraft systems.
https://www.cse-distributors.co.uk/cable/technical-tables-useful-info/table-4e1a/

http://www.southerntemp.co.uk/reference/wire-csa-calculator/ measure strand diameter with a micrometer preferably.