And the TP4056 is still indicating that it is charging, and that the battery has finished charging? I had thought of doing the same thing, but decided on a dedicated solar charge chip as it would make better use of the solar panel (it monitors the input and changes the charge rate depending on what the panel can output at the time), and would also keep the battery fully charged during the day, rather than the between 85% and 100% the TP4056 would if the battery fully charged (the TP4056 charge profile lets the battery fully charge, and then cuts out until the battery voltage falls a certain amount, and then restarts charge, and keeps following that pattern). In reality it probably doesn't really matter in the slightest, and is good to know that the TP4056 appears to do the job quite well on its own.