As first troubleshooting step, make sure you have an original or an Apple MFi certified cable as aftermarket cables around are of all sorts and may give any issue with charging, up to the extent to kill charging circuitry on the logic board. You didn’t say what iPhone previous history was, if known at all, but fact that you had to replace battery and charging dock may point to a widespread damage that might have involved the logic board. Hard to tell much without thorough testing, but take that into consideration if problem is there also with a good quality cable.