Which replacement battery is best for LG G4?

[poflarity]

My 2 year old LG G4 is losing it's charge quickly. My phone is used for phone calls, occasional google searches and watching short clips of my grandchildren. I'm assuming the battery needs to be replaced. What is my best source for a best priced reliable replacement?

 

[Reynod]

You can get a 5550mAh battery as opposed to the 3800mAh battery ... might last a bit longer.