Do you mind if I charge my phone at your house?
Maybe you do, but if I still did it, you wouldn't be able to spot it in your electricity bill.
How about 10 phones?
No, let's make it 100 phones charging at your house. Each phone only charges for 1 hour/day, so on average 4 phones are charging at any given time. Your meter and main breaker board can easily handle it. 1,000 phones are probably also doable.
Assuming you are using 800 kWh/month, 1 phone at your house is the equivalent to 62,500 EVs added to the Thai power grid.