Electron and Lipo

I have searched for this answer but cant seem to find what I am looking for. If I wanted to just plugin the LiPo battery that is supplied with the asset tracker particle Electron kit will it handle shutting off when the voltage gets to 3V? Do I need to do anything to ensure that I dont damage the LiPo on my project? I will be using this as intended and planning to hookup the fully charged battery and send this thing out but it could be without power for over a week until I am able to retrieve it. Any advice is appreciated.

The LiPo has undervoltage protection that keeps you from damaging your battery, but the voltage threshold is well below the minumum voltage the Electron needs to run reliably.

To protect the Electron from brownout situations you should check the SoC of the battery in avoid cellular connection and use deep sleep as much as possible once the SoC drops below 20% (or how low you dare to go :wink: )

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Do I risk “bricking” my electron or when I recover it and charge it back up should it be fine? I have read a few things that mentioned running below battery voltage caused issues but I did not research the context of what they were doing. Thank you for the information.

I read that on the new firmware version 0.7.0 this issue had been mitigated? Can you tell me if thats true?

You shouldn’t need to worry about that. The 20% SoC check recommended by @ScruffR above will keep you out of odd situations with cell connectivity and complete data transmissions but I think bricking is a very low probability event if you use their battery. I’ve asked questions along similar lines and think you may find another useful nugget or two in some of the responses, like this one: Smallest viable battery for E-Series (LTE M1 or 3G).

Thank you for that. I just need to figure out how to adapt my code for that. I already have functions that are checking SoC and outputing the information. Thank you again everyone.

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I wouldn’t overthink it. Something like

if (battery.getSoC() < 20) System.sleep(SLEEP_MODE_DEEP);

should do the trick if you’re planning on recovering and recharging the thing yourself. Maybe wake up and double check every so often (giving it enough time after waking before checking) but even that might not be necessary. Particle says that battery.getSoC() is heavily filtered so you’re unlikely to run into an occurrence of a low % spike that erroneously puts it to sleep in my understanding.

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Awesome advice thank you.

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This is probably a really stupid question but… If I use that code and in my loop SoC is less than 20 and it initiates the SLEEP_MODE_DEEP function will the unit be able to detect when it receives power again? Do I need to put a timer on that and have it check the SoC status again? Just dont want to get into a situation where its bricked.

I really don’t think bricking is likely at all here. How you handle this depends on your use case. Here’s what I’d do based on the limited info I have on your application.

Easiest option:
If you plan to recover a device and charge it manually before redeploying, you might just want to hit the reset button after charging so that starts at the very top of your firmware, recognizing that it’s now back above 20%, and chugs along as intended till it gets back to < 20%.

Only slightly more challenging:
Jumper VUSB to WKP. When you recharge using a USB cable, it will then trip WKP (5V tolerant) to come out of SLEEP_MODE_DEEP and start from the top. Though if it makes it through to the SoC check logic and it’s still under 20%, you’ll have to do the first option after you charge it for a bit anyway so this is only advantageous if you can’t access the RESET pin/button for some reason.

A little more detail on sleep modes here (and in the docs, of course): Electron SLEEP_MODE_DEEP tips and examples.

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That’s what I did. My code is on the forum somewhere.

I put the Electron into deep sleep mode when the SOC hits 20%, and then wakes up every hour to check if the battery has been charged up above 20% before resuming normal operation. I was charging via a solar panel and this setup worked for many months without issues over the winter.

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Thank you that is what I wanted to know. I will consider this and figure out what will work best.

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