Because it will take forever and a day to charge. Actually, even if it’s a legit charger that properly fast charges according to USB rules, it may not work.
Galaxy Note 8 battery won’t charge, warranty replacements are refurbs
Best to keep a power bank around your Note 8 if it’s still alive. Some owners let their device run to zero and have found that a charge couldn’t turn it back on.
Sony Xperia XZ Premium’s Smart Stamina mode actively tracks battery health
Smart Stamina mode reminds us of a good feature that HTC included in its Sense Companion AI engine: it delivers power info and lets you act quickly on it.
iPhone 7 charging rate the same sort of slow as always
With your iPhone 7 or iPhone 7 Plus comes a 5W charger. Because these phones have the largest batteries we’ve seen on an iPhone, they take a while to fill.