I wonder if there is any benefits from using a PSU, a MeanWell or similar compared to an "ordinary" charger like this one:
20S - 72V (84V) 12amp Lithium Battery Charger ?
Two MeanWell, I'm building a 20S li-ion pack, costs about 400$ together, the one I linked to costs 150£.
According to this thread, #8:
chargery spam consolidated from discussion threads Chalo states that a PSU is better.
The "only" difference between the two (assuming it's a CC/CV PSU, like an LED PSU or Lab(oratory) PSU)**** is that a charger is designed to turn off when current drops below some preset limit.
A PSU will "never" turn off completely. (you can change this by buying a board that will cut off the output or the input when a certain time has passed, or when current drops below a certain point, or voltage above a certain point).
****If it's a typical PSU like laptop power brick, computer PSU, or other fixed-current/voltage-output PSU etc., it's probably hiccup-mode current limiting, and is not useful as a charger.
As far as which is better, it depends on your specific usage case.
For instance, on my SB Cruiser trike, my "charger" is bolted to the bottom of the trike, where it gets shaken and vibrated quite intensely, heated to >130-140F by the hot asphalt roads, chilled <freezing a couple nights a year, submerged in flash flood waters every so often, etc. So rather than a typical charger that would probably have failed and been replaced several times by now, I use a Meanwell HLG-600H-54A, because it's solidly potted.
But because it never turns off, I try to make sure not to leave it charging longer than the actual charge time; manually turning the system off when it's full.
If you're not carrying the charger around, and it's in a clean cool environment, you can use a typical charger, and just monitor the fan so that when it starts making noise as it ages you can replace the fan (or the charger) before it fails and causes overheating.
Cheap stuff is usually made cheaply, so...don't buy cheap "junk" and it will work well enough, whichever way you go.
PSUs that are well-made, like the Meanwells (not necessarily any of their clones), Sorensons, etc., are likely to last for a long time (years, at least), so people using these well-made PSUs as chargers are likely to recommend them over the typical cheap charger.
A good well-made charger will be just as good as the well-made PSU, as far as that goes. I've never had a good well-made ebike battery charger, so I can't provide any brand names like I can for the PSUs. The best one so far was made by Modary, but I'm not sure it's really any better than Kingpan, etc.