Why my samsung galaxy tab s2 slowly charging

[AC Question]

I have samsung galaxy tab s2 about 2years and now after update it to a new software i have a little problem with charging i plug in to charging but it take along time to charge it says slowly charging you need to use charger that cane with the device i lost the charger about a 1 years ago so I buy a new one and it was working good but after update it need the original charger and my phone not charging well