I have tried many off brand Surface chargers in the past and they were all absolutely terrible, plus I was a bit worried 3rd parties weren't complying to MS standards when it came to the Surface connector, it's not a very standard port after all.
Luckily the SB2 can now charge via USB C which is a much more widely accepted standard, they don't make ones with the same wattage as a SB2 charger but as long as you aren't maxing out your components all at once you should be just fine: http://a.co/dDe69de http://a.co/8wf0fSf