replacement battery from iFixit will not charge

I replaced the battery in my iPhone SE 1st generation with a kit that I bought from Amazon - turned on fine but would not recharge. used good charging cable and apple charger and it made the little connection “ding” and showed that it was charging but would not go past the 20-25% that it showed at startup. So I returned that one thinking it was a bad battery. Bought a kit from iFixit and have exactly the same problem. When first plugged in it showed about 25% and I turned it off and left it plugged in for about 4-5 hours before checking again. no increase. Left it charging overnight and on checking it showed 10%! It works fine and the screen looks good. Because it’s a higher amp than the original, I then tried using my iPad charger which is rated 2300amp. No better. We opened it up again and checked the connections and everything looks good. Don’t know what to do except return the battery or buy a new phone.