(...already posted earlier, but here goes again)
5-15V/2.6A, or 13-39W. Most (all?) standard USB-A chargers seem to max out at 5V/2.4A (12W), so that's the biggest question about whether or not they'll work. To get more it seems like you need to step up to USB-C ones to get to 3A (the official car adapter is listed as 5V/3A). It doesn't seem like that Benson Leung guy has tested out too many USB-C batteries so I don't know which ones are possibly hazardous.
I wouldn't buy now to be safe but if you do, be wary of the ones with big numbers cause they just add up the total power to ports, you have to look into the details. Like I saw a five port 50W charger, but each port was limited to 5V/2A (10W). Or 4.8A, when it's two 2.4A ports. (Edit: exactly like the Anker 4.8A battery linked in the OP actually)