lg g2 battery replaced issue

[choco69]

I am having an LG g2 model F320L but its battery was really irritating me first of all it charged to 100% very slowly and drains in about 2 hours that's why I replaced the battery but now when I plug it in it won't boot up just the red led light blinks and sometimes the LG logo comes up and goes back continuously
I thought its a display or any software issue but when I snapped the old battery it turned on as it was before so whats the problem here plz help me?
is it any software issue or any issue with the new battery?
thanks in advance!

 

[Mooncatt]

That it is a rather old phone, so I suspect even a "new" battery would've been sitting on the shelf for ages before it got to your hands. It's likely that battery is also deadfrom self discharging. I'd plug it in and let it set an hour or so to see if it charges enough to turn on. If the voltage is too low, it is possible the phone will not boot.