I’m not sure where you live, but I believe every battery sold in the US legally is required to label their I/O voltage and amps, and capacity voltage, amp hours, watt hours.
At the very least, every wall outlet and power bank I’ve seen has text somewhere that tells what it outputs, with the powerbanks aswell having capacity, both amp hour and voltage. Though I will say the text is rather small.
At the very least, every wall outlet and power bank I’ve seen has text somewhere that tells what it outputs, with the powerbanks aswell having capacity, both amp hour and voltage. Though I will say the text is rather small.