I have a MacBook Pro (15-inch, Early 2011) which came with a L shaped magsafe charger. I have been having problems for sometime now, wouldn't charge properly, cut off randomly, charger would cut out/not good connection. I replaced the battery, bought new chargers, reset the SMC and NVRAM many times. Eventually I gave up on it and let it sit for many months and used a work laptop.
A couple days ago I decided to see if it would start and of course the L shaped charger I bought from Apple wouldn't work, I then plugged in my wife's cheap Amazon T shaped replacement charger and it connected great and started charging perfectly. I have tested many perfectly good L shaped chargers since and they will not work well, keep cutting out.
Any ideas? Is my port wearing out and that T shape just happens to fit better?