things like casing i'm ok cos its easy to tell they are either broken or not upon unboxing. but for electronics its very troublesome to claim warranty if i receive a lemon if buy online. IMHO its not about price but more of the hassle. eg; wouldn't wanna throw away a powerbank just after a week of use when it becomes faulty.
Depending on which shopee seller you buy, they give you seller's warranty for said amount of period. If you are so concern about initial workability you can don't confirm that you received your product already and request for a return or refund if it turns out faulty.
If you are talking about long term warranty eg. 1 year store product warranty I can't advise you on it. Because I personally won't take the hassle to head down to their service center to get a power bank sorted out because for the price I'm paying it's not worth my time. I'd just get a new one.
But generally xiaomi powerbank's QC are pretty good. If you don't find faults during initial usage I personally think you won't have any issues for at least a year. (IMO)
It all rounds down on are you willing to extra for more assurance, sort of like AC+
But from my years of using xiaomi powerbanks, never once I had a faulty one long term. IMO YMMV.
