*#That's only true for cheap fast chargers.
A MaHa C9000 charges and discharges, cycles etc. It is a true battery management system.
Fast chargers are fine ... IF they cut out before overheating or overcharging.
The C9000 is very good at that; the cells are never hot only a little warm (normal) after charging.
The C9000 lets you fully program the charge rate. So you can do a 1/10th C slow or 1/2 or higher C fast charge.
Either way the C9000 will not overcharge or overheat your cells.
Do some research.
Google: Maha c9000 review
I know I sound like an advert but I have had significant experience with rechargeable battery technologies in various applications over the last 20 or so years. (RC aircraft; portable radio and computer gear (warehousing application); computer UPS etc).
I know what works; also what is myth and fact.