Anyway , the danger for the gp32 would be if the voltage is HIGHER than 3V ... So 2.4 or 2.5 wont harm it .... And anyway , most of us are using it with rechargeable 1.2 or 1.25 batteries ...
And BTW, best for power supply is to use a regulated one, giving always the 3V , because cheap ones tend to create "waves" on the screen (at least with NLUs and FLUs , dont know about BLUs) Bought one for like 5 or 6 euros last year , so they are not thaaaat expensive (0.5 / 1 euro more than a "cheap" one)
And BTW, best for power supply is to use a regulated one, giving always the 3V , because cheap ones tend to create "waves" on the screen (at least with NLUs and FLUs , dont know about BLUs) Bought one for like 5 or 6 euros last year , so they are not thaaaat expensive (0.5 / 1 euro more than a "cheap" one)