The Redeemer can operate on as little as 3.6V up to 18V, on a regular 9V battery it should last for several hundred hours. So if you make a habit of checking the battery when you change strings you should always be in good shape.

Another feature of the Redeemer is that even with no battery you’ll have some signal (albeit un-Redeemed and at a lower volume) removing the battery is not meant to be a way to bypass the Redeemer (that should be done with an “in/out” switch if desired) however, it will pass enough signal to get through a show – you don’t need to worry, the guitar will not suddenly turn completely off in the middle of a song. 

Note: If you have a first-run Redeemer with a very low serial number (below 200 or so) then you will actually get no signal without a battery (BTW – you check this by removing the battery). You have two options, 1. Make sure you check the battery when you change the strings… 2. Trade it in for a discount on a new Redeemer (but, you would be trading in a low serial number which is sure to be a collector’s item someday worth thousands on EBAY – which is why I don’t mind getting those back and hiding them in my bench – just kidding – or, am I?). I suppose there is a third option – just click here and order a new Redeemer ;-)