Power Bank circuit 1s or 2s identification

Hi..
I bought the below power Bank circuit from online where it was not mentioned the input voltage so i guessed 1s single li-on battery. After receiving it when i connect to 1 Battery it will in few seconds show low battery, tried few batteries in parallel but still with very little voltage drop it shows the last battery indication. I did not connected 2s battery because i am not sure and don't want to burn the circuit. Any help will be appreciated.

All the power banks I've seen are 1S - I doubt this would be any different.

Have you tried charging them after connecting them? - a new Li-Ion will be relatively flat.

Nigel Goodwin said:

All the power banks I've seen are 1S - I doubt this would be any different.

Have you tried charging them after connecting them? - a new Li-Ion will be relatively flat.

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All my 18650 were fully charged using another power Bank circuit i have.

skmdmasud said:

All my 18650 were fully charged using another power Bank circuit i have.

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Try charging them with the new one!.

Nigel Goodwin said:

Try charging them with the new one!.

Click to expand...

Finding was easy, with no battery power bank circuit was give an output of 4.12 v which makes it clear that it charges 1s battery only. As per my testing it can output over 2 amps and due to this the battery voltage drop was a lot and the LED indicated it accordingly. I connected 6 18650 battery and the voltage drop was less and everything worked as expected.