Iphone 6s charges for a few seconds then stops...?

Hi,

I have an iphone 6s 128gb. I am up to date with the latest IOS.

A couple of weeks ago, i ran my battery down til it was dead, i plugged it in to a friends car charger with a non apple cable to charge (which i have used before without an issue). The phone showed that it was taking the charge. After a few minutes, it turned on, but before i could do anything, it turned off and was no longer taking a charge. This just kept on cycling round and would not charge beyond 4% so i gave up.

An hour later, i plugged it into my non apple charger, and it too the charge and charged with no problem. I put this down to a dodgy lead, even though my friend still uses it happily.

Now, its happened again. My phone was at 3% battery so i plugged it in to my mains, with the official apple charger, plug and lead. It charged to 5% then would make the noise as though you have just plugged it in again. The charge would then stop til around 2%, and then begin taking the charge again. During this time, i tried fiddling with the connection, and also left it without moving it at all.

Now the phone has died. I have tried to plug it in to my Mac and my mains, but it shows the symbol asking me to plug a charger in.

I dont have a clue why it is happening. but i know its not the plug or the lead, and not the connectivity with the phone. Its never had water damage and not been jail broken.

Is there anyone that may have any tips or advice as to what i can try and do?

thanks