Maintenance free CubeCell node for > 3 months

koeben · January 1, 2020, 6:24pm

Hi,

I am currently working on a node with the CubeCell board and a BME280 to track THP every 15 min.
When it comes to the power supply, I tried a coin cell (CR2450 with 640mah). But it gave a battery voltage of 240 mv, and after a few messages it stopped working, so I assume the peak current was too high for the coin cell.

Coming to the LiPo option, since the sleep current is much higher and LiPos have a higher potential for failures (also fire), I wanted to stay away from that. Additionally, I am not sure which LiPo has a low self discharge current and want to use them inside, so solar panels are not an option.

This is why, I wanted to give a try with the coin cell.

Do you have other suggestions?

Thanks,
Ben

BDM · December 31, 2019, 12:24pm

Hello,

You can have look at the specs of LiSOCl2.

A very interesting high level of comparison is given in this page.https://www.disk91.com/2019/technology/hardware/battery-technologies-for-iot-compared/

junk430 · December 31, 2019, 1:09pm

Don’t get caught up in the latest crazy battery tech and don’t underestimate the energy in a couple D cell batteries.

I was reading about a team creating a remote sensor buoys in the antarctic. I was really interested to find they use a massive bank of D batteries. I think it was over 100. Why? High energy density for the size, price, and really low self discharge.

rsmedia · December 31, 2019, 1:13pm

just take some NiMH batteries will last long an are easy to handle.

koeben · December 31, 2019, 4:03pm

Thanks, that sounds promising. Did anybody of you try the LiSOCl2 with a CubeCell?

The specs are saying that they have a voltage of up to 3,7v when fully charged whereas the CubeCell spec only allows up to 3.5v with 3.3v option.

BTW: For both 5v and 3.3v pin power supply, I would use the VIN contact? 2nd below user button?

rsmedia · December 31, 2019, 4:37pm

Connect the battery to the battery socket

koeben · December 31, 2019, 5:06pm

But then I would have the power regulation stuff again, right?
Nevertheless, can somebody please bring light on the question, which pin to use for powering via 3.3 or 5v.
If I use 3x1.2v cells on the battery connector , is it ok with the loading management of the CubeCell, so it does not overcharge? I want to understand the different options, I‘ve got…

Thanks!

Andreas · January 1, 2020, 12:27pm

Can’t you put a solar panel on it? I’ve had a couple of cubecell’s with a 1000mAh LiPo at work for months.

tuxscreen · January 1, 2020, 2:10pm

He uses the CubeCell inside, he already thought of that
BR
Marc

koeben · January 1, 2020, 4:32pm

Thanks Marc,
yes, basically for me 2 questions remain open:

Which Pin to use for 5v and 3.3v direct supply w/o battery connector. But 3.3v is more important for me.
Is it possible/advisable to plug another battery on the connector to use and charge another battery than a 3.7v LiPo. E.g. 3x 1.2v NiMh or Li-FePo4 with 3.6v?

Ben

OMatthias · January 4, 2020, 6:29pm

I think you should have a look to this power management.

it comes from
https://github.com/rocketscream/MiniUltraLoRaWAN/blob/master/MINI-ULTRA-LORAWAN.pdf
And when you can use normal eneloop pro