Some interesting information about Carbon-Zinc batteries

[phillip]

Here's a webpage that I found as I was looking for Carbon-Zinc 9V batteries.  Lots of good information including advantages and disadvantages, a construrction cross section of the Eveready "216", chemistry, output capacity graphs, discharge graphs, and internal resistance.

http://data.energizer.com/batteryinfo/application_manuals/carbon_zinc.htm

Hope someone finds it interesting

Phillip

[bwanasonic]

I am I understanding correctly that  "sensitive  to changes in the discharge rate and/or duty cycle." means that leaving a device on may get better battery life than switching it on and off frequently?

Thanks for the link BTW!

Kerry M

[Peter Snowberg]

Very cool! Thanks!

[Paul Perry (Frostwave)]

I am I understanding correctly that  "sensitive  to changes in the discharge rate and/or duty cycle." means that leaving a device on may get better battery life than switching it on and off frequently?

I'm sure that isn't true. Unfortunately.

[stm]

Ripley's Believe it or Not:

Many years ago I read an application note from National Semiconductor about a LED flasher oscillator IC, the LM3909. They DID mention that the circuit consumed so little power, that under some circumstances battery shelf life would be extended !?!?

Voila, I found it!  

This quote is taken from page 7 of the application note corresponding to the aforementioned IC, available at http://www.national.com/an/AN/AN-154.pdf

"Further, its standby battery drain of 100 uA yields a battery life
close to (or, according to some experiments, exceeding) shelf life."

[phillip]

I use Carbon Zinc batteries in all my effects (because they're cheap!) and I've noticed that in my wah pedals, no matter how much I use them, the voltage of those batteries have increased since I put them in.  When they were new they measured about 9.6V, and now they're measuring 9.8V-9.9V.  

Dunno why that happens, but I do know that batteries do have a certain amount of "bounce back."  By bounce back I mean that if the battery is heavily used one day it could drop to 9.3V, but if you take the voltage reading of the same battery the next day it could be back to 9.6V again.

Phillip

[Ge_Whiz]

During use the zinc is dissolved away in the electrochemical reaction. Since this can remove surface impurities that build up during non-use, occasional discharge can improve the operating conditions of the battery. Also, zinc-carbon batteries benefit from recovery between discharges as the internal reaction returns to equilibrium before the next use. Yes, it is possible to improve battery life over the 'shelf life' by a small current drain (as provided by most pedals), and / or a favourable 'duty cycle', but this may depend on how the manufacturer defines 'shelf life'. In terms of energy per unit mass, volume or dollar, zinc-carbon batteries are undeniably inferior to more modern types.