Low-Power Battery Backup Reference Design


Senior Member
what variety do you prefer for flavor or texture?

sorry lance I'm a little/very late from ur question
I am on a diet I've been 165 lbs 20 years ago when I was 20
and now I am 166lbs so I have been forcing my self to eat more
healthy foods like donuts,twinkes, candy and sugar galore sodas
trying to get to 170
and i going to celebrate when the blinker dies
I think you have a world record here so far ...which for reals is good info


Senior Member
world record here so far
Never imagined it might be a topic for consideration 9+ years later. It is good to know that it is possible to run a low-drain picaxe on batteries for a long time.

Re "record", haven't heard from papaof2 for a while, so don't know if his water sensor is still running (and on same batteries), but his project predates mine:

Unfortunately, the site referred to for details is dead.


Senior Member
Yesterday was the 10-year anniversary of the first posting in this thread, and the green LED is still blinking away, approximately every 7 seconds, on the original 3 AA batteries. The battery level is now at 3.56, down from 3.67V last year. That's approximately 45 million blinks.

I had no idea that the PICAXE could run for so long on what manuka might say is "a whiff of the odd electron".

Now back in its box for another year.


Well-known member
Lance, I put a rock in a box way back near the time you started this experiment. Its still in the box and still a rock. :D

PS. Please, just having some fun! :D


Senior Member
... still in the box and still a rock ...
The question is, by how much has the useable energy in the rock been depleted? At a rough guess, I would suppose that your rock will be better for a much longer time at whatever a rock is good for than my batteries will be for what batteries are good for.
Lance thats awesome ....calculating the math here ...I suppose it will last for another 2 to 12 years if I round up correctly :)
but its still cool to know its still going strong


Senior Member
But does the LED still flash when the box is closed or does it only flash when the lid is off? :p
The box is just for storage. But this may be the same as the question, "If a tree falls in the forest with no one to hear it, does it make a sound".

Let's see--I could install a flash detector, or would just monitoring the LED supply line for plus voltage suffice?

Nah, I think I'll just suppose that what happens when I'm making an observation is the same as what happens when I'm not (Schrödinger and his cat notwithstanding).