Nexus 5: Battery Status: Unknown, Battery Percentage: Stuck at 0%

[AC Question]

Hello all i have been using the LG Nexus for almost a year now. I started facing some issues with my phone recently. First it used to stop charging after 3-4 seconds(it showed the charging on the lock screen for a mere 4 seconds and then it would disappear), the cable was plugged in but it wont charge i did everything i could but it was of no use so i made a small charging circuit to charge the battery directly instead of using the charging IC. But with that circuit it only went to 72% and then it wont go up also it would take 18hrs to charge the phone. After sometime i found a spare Blackberry Charging cable i plugged it in and voila the phone started charging again. So i removed the circuit and charged the phone it charged fine but only until 62%.
But now suddenly it stopped charging completely and first it went blank and after sometime it turned on and now it only shows the exclamation mark on the battery or 0% when plugged in it gives the status of the battery as unknown. Cant connect it to Laptop or anything, even changed the battery but it's still the same. Does anybody know what the problem is here i mean it's not switching off it shows 0% battery but it stays on it's been on for almost 5hrs now.

P.S. I know i should change the phone but i am literally broke these days lol so cant afford one atm. Thanks in advance

 

[Rukbat]

"so i made a small charging circuit to charge the battery directly instead of using the charging IC" which puts 5 Volts directly on the battery, which eventually destroys it.

I'd guess that the charging circuit and the battery are both shot, so you need a battery and a motherboard.