I want to remove the USB plug from the end of my passthrough and solder the wire ends directly onto a 5v battery pack terminals. The M401 passthrough uses a green and blue wire and I believe the auto cigarette part has a miniature circuit which reduces the incoming current to 3.7v (which suits me).
How can I find out which colour wire to solder onto the positive and negative battery terminals? Does it matter which way around they go - or do I need to buy a voltmeter to find this out? I can see which coloured wire is currently soldered onto each peg in the USB plug (ie left and righthand sides) - and I wonder if this shows positive and negative?
How can I find out which colour wire to solder onto the positive and negative battery terminals? Does it matter which way around they go - or do I need to buy a voltmeter to find this out? I can see which coloured wire is currently soldered onto each peg in the USB plug (ie left and righthand sides) - and I wonder if this shows positive and negative?
