The boards are marked. Power in is at the USB socket, but there are also two connections for wires: "IN+" and "IN-".
At the other end of the board the output is marked: "B+" and "B-" . There's also: "OUT+" and "OUT-", I assume they are the same as the "B" connections.
The boards have two LEDs - red for "charging" and green for "battery full". You may want to mount the board and drill two holes so that the LEDs can be seen.
As I mentioned in #15, the blown-up chip and/or other faulty components on the board may pull down the voltage across the battery, prevent it charging, and short the output of the new USB charging boards. You could do a quick test with your 5v 1A supply at connector 2. An Ammeter is series should show a current draw of about 500 mA or less. A voltmeter across the power supply should show the voltage dropping to maybe 3.5 or 4 volts, but not zero.
At the other end of the board the output is marked: "B+" and "B-" . There's also: "OUT+" and "OUT-", I assume they are the same as the "B" connections.
The boards have two LEDs - red for "charging" and green for "battery full". You may want to mount the board and drill two holes so that the LEDs can be seen.
As I mentioned in #15, the blown-up chip and/or other faulty components on the board may pull down the voltage across the battery, prevent it charging, and short the output of the new USB charging boards. You could do a quick test with your 5v 1A supply at connector 2. An Ammeter is series should show a current draw of about 500 mA or less. A voltmeter across the power supply should show the voltage dropping to maybe 3.5 or 4 volts, but not zero.