Mac won't turn on without disconnecting and reconnecting the battery

Hi, my A1465 had a battery issue message for a while, the mac would close down within a few mins of being removed from the power adaptor. Then wouldn't turn on with or without external power. I changed the battery, it powered up immediately, I charged the battery and it worked. I shut the laptop down and left it off charge, the laptop now wont open again. Additionally when its plugged in, the magsafe starts green, goes orange. When i press and hold the power button light goes green when i release the button and then back to orange, but still wont open. If I disconnect the battery, then reattach and then apply, power the laptop comes to life!. Can someone advise me please. Paulburton9@googlemail.com thanks