What’s worry with my new sony VGP-BPL1 battery?

Question :my laptop’s original sony VGP-BPL5A batteryhas been dead for one year ago and i’ve been using the adaptor for power. recently i bought asony VGP-BPL1 batteryonline but i have a problem. i can’t turn on my laptop with just the battery. i need to plug the adaptor first before turning it on and then i can unplug it. after that the laptop would operate normally unless i turn it off then i have to plug it again. what could be the problem? is it the battery? thanks! Answer:If you bought a replacement battery only, normally it not the same specs as the original ones… you have to check if it has the same mAm and and have it charged in full.The best way is buy other type battery : Dell 1691P battery , Dell G5266 battery , Dell Inspiron 9400 battery , Dell U4873 battery , Dell Inspiron 6000 battery , Dell Inspiron 9300 battery. Use this battery you problem will be solve.