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How low should I let the voltage go on my twine before I change batteries?

The portal shows my voltage to be 3.05 v, how low should it go before I consider switching out batteries?

Best Answer

  • 12 Comments sorted by Votes Date Added
  • Robb, you'll get an email at 2.4V, which should give you about 5 days before the batteries actually die. We're also improving the battery life as we go along — so as we get better data, we'll improve the estimates.

Answers

  • How long is the operanting time with the 2 batteries ?
    How can we have details about the MAC layer in use in the networking stack ?
    How can I control the sampling schedule parameter in order to improve the batteries' duration ?
    Generally, I wonder about the hardware and softaware datashets of the motes ...
  • My Twine reads 2.8 vdc out of the box on the portal. Is there some way to monitor load as different parts of the Twine are activated. Does the number of "rules" correlate to increased battery drain?
  • The number of rules shouldn't make very much of a difference. A lot of battery power is used whenever Twine has to talk - going into setup or fast mode, loading rules, connecting or reconnecting to a network, triggering rules.
  • I got my twine last week, and the batteries showed 2.95V. Only a week later, I got an email telling me the batteries are low at 2.5V. I have not touched it for a week, the moisture sensor has been inserted, and it is not in high-speed update mode. Why is it burning through the batteries so quick?
  • When I click on the " I'm going to update less often to save power. Keep talking fast" button, how long does it keep talking fast before it goes back to low power mode?
  • edited December 2012 Vote Up0Vote Down
    I'd like to run the Twine on Eneloop batteries. Any issues?
    Fully charged, they read 2.66v.
    At what voltage will Twine shut down entirely?
    Is there a way to change the voltage threshold for the "Low batteries!" email?
  • I let my twine run until it stopped reporting. The last report i received said the voltage was 2.39v. That was on day 15 after adding new batteries, with twine only monitoring temperature.
  • As I'm reporting in an ongoing experiment elsewhere, I am on day 12 after the 1st low battery waning, running at 2.48 V. That makes it about day 18 on a fresh set of batteries.
    Looking at specs of circuitry likely to be used inside the Twine, I expect my experience will be like Bill's; a shut-down near 2.4 V. With the Twine doing "nothing" my guess will be for another 2 to 3 days, based at the present voltage drop history.
    That said, this is still nothing like the "running for months" in the original blurb. But, again, innovative design always runs up against physical realities that were not considered in the original concept, and in the end, if you are going to get out a product at all, compromises have to be made. Some of these may be rectifiable in the next model, or by firmware updates, some may become facts of life.
    Hindsight is always more perfect than foresight, and I suspect at this point the Supermechanical team might well wish to re-visit the decision to go with AAA batteries, vs. AA batteries, which would have given twice the energy supply with very little increase in footprint.
  • My Twine stopped reporting at 2.45 V.
  • Just got my first low battery alert - 18 days after turning it on, and I have also been intermittently using a power supply. Actually I use the power supply most of the time - I use it to charge my phone when I get home, so the Twine is on power for at least 10 hours a day.
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