Battery life

What is the best way of estimating how much life is left in a 9V battery ?

I used to just touch the electrodes with my tongue and see if it sizzled however, as i get older I am thinking that their has to be a more elegant way and even quantitative way !

Originally Posted by: Dr_simonWhat is the best way of estimating how much life is left in a 9V battery ?

I used to just touch the electrodes with my tongue and see if it sizzled however, as i get older I am thinking that their has to be a more elegant way and even quantitative way !

Duracell and I think Energizer sells 9V battery packs with little testers in them. At least they used to, maybe they've been phased out now that they have the built-in testers.

Anyways, what I'm trying to say is that, at one point, I bought a pack of 9V batteries which contained a little tester strip that you held against the terminals and a little bar would turn yellow and indicate how much juice was still left.

I had thought of that, and unfortunately I had a box of assorted 9Vs from stomp boxes, mini amps etc etc and don't know how much life is an any of them

[font=trebuchet ms]A voltmeter alone doesn't give you a true indication. Measuring the voltage with a 470 Ohm resistor across the terminals is better. You need to have a load drawing current in order to assess the battery. 470 Ohms will draw 20 ma, which is slightly more than one LED. A typical pedal will draw about this much. The LED usually takes more power than the effect does, unless it's some multi-FX monster. If you measure less than 7 volts this way, the battery is just about done.[/font]

I never thought about using a resistor but that makes perfect sense. Good tip!

Lordathestrings to the rescue !!!

Cheers dude !

[font=trebuchet ms]A classic gearhead response! :rolleyes:

All you really need to do is measure the voltage difference while turning the effect on and off. A weak battery can't supply current while it's under load, so the voltage drops noticeably. If you can get the meter probes onto the battery terminals while it's still in the pedal, you don't need to fart around with a resistor. (As second guesses go, I much prefer my own).[/font]

cool, I can do that !!!