Iphone SE Battery Problem

Last 3 months i dropped my phone in the pool and it I put it in rice for 24 hours. After that, it became fine, but I noticed that the battery drained quickly and my phone automatically shuts down. One day, I forgot to charge my phone and drained the battery. Then it won't charge up to more than 1% and it keeps rebooting. I asked an IT friend to replace the battery and it worked. After a month, I forgot to charge it again and it won't charge up to more than 1% (again). So, for the last time, I went for a professional IT guy and let him replace the battery with a new one (i guess). Again, it won't charge and it keeps rebooting. I tried plugging it for 24 hours, but it's still on 1%. Please help me.