However, as i earlier said how can i make sure that a adapter i use will be good enough for a particular phone, considering that it didn't come with the original make.
The phone information should say what current rating is needed for fast charging. If the power unit meets or exceeds that current rating, and is made to conform to the relevant specifications, the phone should fast charge - otherwise it will charge at a lower rate.
For best overall battery life, it's not so much what charger you use, it's more down to when and how much you charge it!
Lithium cells age fastest when fully charged, and that aging is accelerated by temperature.
Ideally they should be taken off charge as soon as they are full, or better still at eg. 80%
Some phones now only charge to 80% if they are regularly charged on the same schedule, automatically charging the last bit shortly before they are usually taken off charge.
Also, not running them down completely extends the life significantly - eg. keeping the charge "span" from 75% to 25% gives four times the charge cycles, compared to 100% - 0%, for the same level of capacity reduction.
Mobile phones are not the worst thing, as at least the battery is being discharged again as soon as they are taken off charge.
The effects can be far worse with laptops, as they are often either charged and left to stand or run continuously on external power - that's the worst possible state for the battery, as it's held at full charge and with many laptop, they run quite warm.
The life of a new battery used like that can be three months or less, compared to a good few years if the charge range is limited and it's taken off charge once the battery is near full.
They do need an occasion long charge for cell equalisation, that's fine as long as the machine is off, so not heating the battery. Likewise, an occasional run down to turn-off point to keep the capacity reading correct.
