So here is a little DIY piece of gear that is super simple to make. And I think it is worth throwing in your gig bag and bring along with your guitar pedals and can really save the day.
This is just a 9-volt battery with a battery clip, soldered to a guitar pedal power cable, that you can plug into most 9 volt guitar pedals to get them up and running. All you have to do is take an extra guitar pedal power cable, and if it is double sided like this one that is meant to hook up a power supply to a guitar pedal, you can cut it in half and you can make to of these backup batteries from one cable. And then we are just going to take these 9-volt battery clips and solder it to the power cable. Now most guitar pedals are barrel positive / tip negative. So I am just going to use my multi-meter to check for continuity so that I know which of these wires that I stripped back is which, and I can see that the outer shield is the tip or inside of the plug, so it is negative, and this inner wire is the outside of the connector, or positive. So I am going to slide on a piece of heat shrink over both wires, and then a smaller piece over just the positive wire and then solder these up to the battery clip. Once that is soldered I can slide this heat shrink up over the positive wire and shrink it down. And then same thing with the heat shrink over both wires, and that is all there is to it.
Now you might be wondering what is the purpose of this thing? I think it comes in handy in a couple of ways. So lets say you use a pedal board and you just use batteries inside each pedal to power it. If one happens to go dead at a gig, all you have to do is grab this little guy and plug it in and you are up and running again. Now I find this to be a lot more convenient to do rather than unplug the pedal and flip it over and replace the battery on the inside, even with this tuner that has this one thumb screw to change the battery, and obviously this would be even more true if you had a pedal that you had to take out 4 screws to get to the battery.
Also if you are using a pedal board that runs off of a power supply and something happens, you can at least plug a couple of these into the most important pedals and limp through a gig. Or the situation that I have come across is that in some venues your high gain pedals, like a fuzz pedal or a distortion pedal are not happy with the power situation and are humming way too loud, often times if you just unplug the from the power supply and run the pedal off of a battery then you can cut down on a lot of the noise. So whatever your setup looks like, if you are using guitar pedals then I think making a couple of these little guys, and keeping them in your gig bag just in case is a no brainer.
Now one disclaimer is that this will not work for every single guitar pedal. If your pedal has the ability to run off of an internal battery than this will definitely work, and a lot of smaller pedals that draw less than 100ma of current will work as well, but obviously the more current the pedal needs the less time the battery will last. I would not recommend doing this with power hungry delays or looper pedals as you could end up trying to draw to much current from the battery and in a worst case situation you could cause a fire. So you have been warned, don’t try this on your big power hungry digital pedals, but for most overdrive and distortion pedals, and some delays and reverbs and things like that this little thing really comes in handy. Hopefully you are convinced of the benefits of keeping a couple of these around just in case, if you are go off and make your own.