Which adapter are you referring to? It would help to better answer the next question.
If the adapter on the "output" side is always 5V, then there's no problem at all as long as the charging circuit can handle the current/voltage, which most should be able to handle. Even a TP4056 works at 5V @ 1A, and 3 in parallel could do 3A.
It's a belkin adapter, with one particular USB port able to deliver the total rated 50W given that no other port is used.
To get the 50W delivery from the adapter, I'd have to use a power delivery decoy module to trigger the 50W.
Didn't know 3 tp4056 would allow the current to increase. Thought the module is designed to "limit" the current at 1A.
Even then I'd have to parallel 7 of those units to get about 7A.
That would mean each cell would be then charged at 2.33A. Any other ways to get to 7-7.5A?
For my understanding/ learning, could you educate me on the part I mentioned above, about "balance scale" of current and voltage with using a converter