[A3rd.Zero]

I recently stopped by rat shack and found a few interesting batteries. Most notibly is the 12v alkaline battery for a "keless entry system" 23-279 which in a pack of 2 costs $2.99. Its a little over an inch long and 1/4 inch wide making it extreamly small and seemingly quite usuable for headamps. I dont have a clue as to the amphours rating as I could not find it on the package or on RatShacks website.

Ill run some tests and see how it fairs on a cmoy. My expectation is that Ill need two in parallel for it to truly preform but im not sure.

Milo

 

[jeffreyj]

The mA-hr capacity of that size battery ranges from 18-33. Zinc chemistry cells will only be able to deliver their capacity if loaded by much less than the 1C rate but the typical CMoy circuit draws about the 1C rate, so you can cut the life down to about 1/4 of what the capacity would otherwise suggest... so, maybe 10 or 15 minutes if it's zinc based or 45 to 90 minutes if its alkaline.

Not a lot of bang for the buck, then: compare this to a premium 9V battery with a mA-hr capacity of ~565, or over 30X more, for the same cost.

 

[A3rd.Zero]

I guess thats to be expected. They are designed after all to be uesd only when people push a button so their life expectancey over a sustained load wold quite short. There are other uses for such a device though so im not too upset. Thanks for the insight.

Milo