I'm not sure how to check the voltage on a wall block - but do you think a 1-amp or 2-amp makes a difference? Or is all in the voltage?No, just check their voltage. I have maybe 5 different single, dual and 4-port USB wall chargers and the 4-port one had the highest voltage that never triggered low bus voltage but others where lower and even down to 4,9V. I have a 10 or 12 port USB power supply and its internal power supply broke down so I bought an external one, it's a 12A one, and that too had a higher voltage close to 5,4V so no more low bus voltage from that.
/Ubbe