One of the things I hear the most, and it’s literally almost a daily occurrence, is “why does this pedal eat batteries so much?” or something similar…
Here’s the starting point, in my opinion of course… what we should all remember when thinking about guitar pedals is that, with the current scope of power supplies available to us, from the dirt cheap (ba doom tish) to the really expensive, there is really no real need to still use them… It would appear, on a global scale, we don’t appear to have any kind of system for disposing of used single life batteries right now, although local recycling is present in a lot of the Western World. So I’m going to go out on a limb here and say it’s probably best to try to avoid dumping them in the trash, or maybe we should be walking away from them as much as possible.
Now, before you say it, I will… “But Eric Johnson says…” let’s face it, we are not Eric Johnson… I consider myself to have a pretty good ear for stuff, and I truly cannot tell the difference between a fresh battery, of any kind, and a decent power supply (providing the same amount of power). Obviously, when a battery starts to die, it tends to make certain effects sound slightly different. But the power supply people have already thought of this and many now have variable amounts of output to emulate and reproduce the symptoms of a dying battery, but consistently.
Another thing we hear a lot, a sub question to the original, is “why do pedals appear to drain batteries so much quicker than they used to” well, the answer to that is simple, pedals tend to be considerably more complicated than they used to. Back in the good ol’ days you have a buffered bypass, volume, gain and tone. These days you often have relay switching bypass, 3 band EQ’s, multiple gain stages and so on therefor the simple equation is “the more stuff it has in it, the more it’s gonna drain your battery”.
With a pedal like the Tumnus, and other K styles (if the pedal is done properly) there will be some serious power shenanigans happening inside, it’s taking your 9v and bringing it up to about 25v. So that makes the pedal considerably more thirsty than if it was just taking the 9v… when you look at the Tumnus Deluxe you have the power coming up to about 25v, 3 band EQ, relay based switching, extra gain… so, that’s why it’s rated at 70mA draw which will chew up a regular battery in no time.
Keeping with the Tumnus Deluxe, if you are using a regular Duracell battery, or even an Energizer, they are rated at about 310 mAh (milliamps per hour). So, if you were to put one in a Tumnus Deluxe, it will start to feel the effects of the draw within a couple of hours. If you are lucky, it will drop below the 9v required and start to flash at you before that point, so I would very much doubt you’d get a gig out of a standard 9v battery. An Energizer MAX is rated higher than the Duracell, so you might get 30-45 minutes longer. Still not enough, I would say, to warrant the cost of a single use battery.
There is a simple equation to work out how long your battery will last, it’s not exact as it’s averaged down from the strict parameters…
Battery Life = Battery Capacity in mAh / Load Current in mA x 0.70
So, if your pedal takes 70mA, your battery is classed as 300maH, it will give you about 3 hours of power. At approaching $3 a piece, a power supply will very soon pay for itself and you won’t have to worry about it dying on you mid epic solo!
One thing to remember, if you use a single use battery, and it gets thrown straight into the bin and not recycled, the following heavy metals are within most batteries… Lead, copper, Cadmium, Lithium, Mercury, Zinc, Manganese, Potassium etc… so, we don’t want tons and tons of that stuff being thrown away, it’s not good for us when it breaks down and enters into the water system.
A decent power supply, you know it makes sense!