17 R4, battery or motherboard issue

Hey, so i recieved my alienware 17 R4 almost 2 years ago as a christmas gift. A little over a year of ownership, my charger broke. At the time i didn't have the money to buy a new charger and part of my work required me to use my laptop. All i could do was use a different charger for a few months that was lower power than what i required and for a different type of dell computer. I was still able to power on my computer and use it. It just charged slowly. (yes.. i know that was a mistake and why i have issues with my computer now). Eventually it wouldn't charge at all But by then I was able to order a new charger through dell. It is the correct power. But after i started to use it, it still said it wouldn't read my ac adapter. It wouldn't charge still. I tried talking with dell support but they really couldn't tell me what was wrong. Just its either my battery or my motherboard. Now i didn't and honestly still don't have the money to send it for repairs. Eventually it would start to turn off by itself and slowly over time would start doing it more and more frequently.. I was concerned but again, couldn't afford to do anything. I tried searching the internet for answers and came up empty handed. And tonight, my computer won't turn on for more than maybe 15-20 seconds. It will turn off, back on, then turn off again. And as far as i know, it just keeps doing that. But after it turns off a second time i just get frustrated and leave it off. I've tried the whole unplugging the battery and adapter and holding down the power button. It didn't change anything. I'm lost. I don't know what to do anymore. Can someone please help me. If not with how to fix this then at least tell me what the issue is so that i can try to find a way to fix it. Any help is really appreciated