[SOLVED] Can there really be bad portable charger?

[mg789setlogelo]

Hi there

I stumbled across a sale in a well known and trusted electronics store in South Africa and they had this portable charger with 12000mah going for around $20-ish. The brand is Swiss mobile which is unfamiliar to me. It doesn't have fast charging or wireless charging. This is one of the cheapest I have seen but I don't know if I should be sceptical. Can some portable chargers really perform poorly? Thanks for the help

 

[Alabalcho]

Yes - they can perform poorly to the point where charged device stops working.