Dude. Your questions are indicative of not having the proper knowledge to do this. 14 gauge wire is good for a 120 volt 15 amp fuse. Sounds like you're taxing that circuit to the max with all of the stuff you have on it already. And, often circuits have branch circuits. That means that the one outlet you are already using in the basement may have other lights or whatever on it. See bucks post. Only use 80% of the maximum of a circuit. Those wires heat up. The breaker is designed to keep you from overloading, nevertheless, it's a device that can fail.
Now if you MUST do it yourself. Snake 12 gauge wire to the basement and use a GFCI outlet. That is code bro. I would over do it and run 10 gauge. That will give you approximately 2200 watts(20A X 110V) of the Max rated power at 110 volts, which is about . The 80% factor is because you will be running that equip at the same time for long periods. Wire heats up. So only use 80% of the max at the same time. So you will only have approx 1760 SAFE watts available. I can't find my meter but, I assume my voltage runs about 110 or so.
Sound like your already overloading that 15 amp circuit.
BE SAFE AND LIVE BRO! Over do it! GFCI and 12 gauge are musts, if you must DIY.
P.S. I made a mistake. The wire and breaker would be good for 20A at 120v giving you 2400 volts or at 80%, or 1920 safe watts.And this is in addition to your 15 amp circuit.