What have I done to my drone?

I recently purchased X5C-1,great little drone for a learner like me..I saw a vid using a phone battery to extend flight time.I tried this and although things looked well,phone battery was charged, connection good,when trying to take off the power only lasted seconds before completely dead…Gave it up as a bad job and reconnected back as was,now what appears to be a fully charged original battery is doing the same thing,10 seconds then nothing.. Have I been a complete humpty?..

Any help would be great folks,as I said I'm a nube at this.