Batteries and Sleep


#1

I have a protoboard with 5 temp sensors, connected to the Dash. I have a 2500mAh LiPo 3.7v. The battery usage is turning out to be more than I expected. I am currently sending data to thingspeak: https://thingspeak.com/channels/111108 The data you can see there includes battery voltage and %.

I am currently sending data every 3 minutes, and project I have a run time under 48 hours on a full charge. It would be nice to get to 7 or 8 days.

Do sleep and deepsleep offer a significant improvement?

Would it make sense to use a ‘power bank’ style battery?
http://amzn.com/B00VWV8LD4

Or would it be better to use a 3v like this?
http://amzn.com/B00XVMXQCI

Thanks


#2

If you are using the Arduino delay() function, you can swap in the Dash.snooze() function and you should see an improvement. The power mode used by snooze() and sleep() are the same. The lowest power mode is deepSleep(), but that requires an external IO interrupt to wake. There is a timed deepSleep on the roadmap, so look for that in a future release.

You can also change the processor speed, which would lower power consumption when not sleeping. From the Arduino tools menu, select CPU Speed: 48MHz.


#3

I am already using snooze.

I’ll give the 48mhz a try.

Thanks!


#4

Just one user’s opinion here… I’ve played with a few of the rechargeable 5V/USB batteries, both large and small. As you’d expect, the larger batteries do indeed contain more energy, but the trick is to find one that will constantly power the 5V USB port – many will deliberately switch off under very low connected device power draw, or when the 5V device is disconnected (which auto-protects the power bank from being drained due to it’s internal 5V converter running constantly). In my limited testing, I’ve seen the power bank battery shut off due to low power draw on the Dash (which is unfortunately more likely when the Dash is sleeping or snoozing). You MAY be able to find a power bank that does the trick (although I have not). Using that 5000 mAh single-cell you linked to may be a viable alternative (IMHO).


#5

The 48mhz seems to have a pretty big impact (updated at 00:18:08 in that chart):

https://thingspeak.com/channels/111108

Seeing battery % climb while voltage drops is a bit odd.


#6

No USB power to the Dash? Powered by battery 100%, yes?


#7

correct … ( plus these extra characters for a minimum of 20 to make a reply :slight_smile: )


#8

@MichaelM I use www.batteryspace.com to get custom size, mAh & C ratings for Lithium Polymers. This also eliminated the waste of the voltage regulator.


#9

Thanks! A good site, for sure.