Brown-outs Despite Healthy Batteries

Hello all!

I’ve recently ran a test following the model provided in Global Asset Tracking with a Cellular Notecard and Datacake on three Notecarrier-A’s. However, there were some issues the cards seem to be having, and I kindly ask for assistance in diagnosing and solving this issue.

For sake of readability, I’ll name the three Notecarriers A1 (for devID ending in 2006), A2 (for devID ending in 9561), and A3 (for devID ending in 5142).

Here’s the process I used to setup this test fleet:

The hardware used included three Notecarrier-A’s, each are equipped with Cell + Wi-Fi Notecards, and are each powered by one 3.6V Li-Po battery. Batteries are wired into JST-PH connectors and plugged into the LIPO ports on the Notecarriers.
Fleet Setup

Each battery was checked using a multimeter prior to testing, and every battery had a minimum voltage of 3.6.

The same continuoustracker.json file was used to program all of the notecards.
JSON screenshot
This JSON file’s role is to schedule a sync every hour. Programming to all cards was done via VSCode terminal and USB connection.

Programming was done just before 12:00 PM on Friday, 7/26/24, and the test was left to run until 8:00 AM on Tuesday, 7/30/24.
Though I’m confident that this is unrelated, I will add that A1 was left on an office desk, A2 was left by the front desk of an office, and A3 was left in a car that was driven two to four times each day.

Here are the issues I’ve encountered (screenshots can be found in the album linked in the first reply):

Firstly, Notecarriers A1 and A2 had occasional missed syncs.
Examples include A1 missing its 3PM sync on Friday and A2 missing its 6PM sync on Friday.

Secondly, Notecarriers A1 and A3 had instances of continuous brown-outs (and forced syncs).
Examples include A1 at 11PM on Sunday and A3 at 4 and 5AM on Tuesday.

Thirdly, Notecarrier A1 eventually stopped sending data by end of Monday. A1’s Red LED intermittently flashes acceleratingly, which I presume indicates that it continuously tries to start up but is unable to.

Given the brown-out information that show up in the _health.qo files indicating a drop of voltage (usually to 3.2-3.4V), I would assume that this is a battery issue. However, I’ve tested each battery using a multimeter and they seem healthy; A1, A2, and A3’s batteries measured 3.60V, 3.64V, and 3.65V respectively.

As a new user, I’m limited in how many links I can attach to post, so I’ll see if I can get any of these put into the replies.

I’m not entirely sure what I should do from here for further testing and diagnosis.
Any guidance would be greatly appreciated.
Many thanks in advance~

Since I can only attach two links per reply, I decided it would be a good idea not to spam the forum with replies and to instead just post the link to the Imgur album.

Album includes:

Battery Testing

A1 Missing 3PM

A3 Missing 6PM

A1 Continuous Brown-out

A3 Continuous Brown-out

A1 Unresponsive

Hi @andyzhao and welcome to the Blues community!

Unfortunately (as noted in the datasheet and store) the Notecarrier A is not compatible with the Notecard Cell+WiFi. We have a new revision of the Notecarrier A coming soon, but for now, as you are seeing, the antenna cables barely reach and there is a possibility of a short due to components on the Notecard hitting components on the Notecarrier. The latter is possibly what you are experiencing re: brown outs.

Otherwise your API requests look good. Personally, I don’t like aligning the periodic syncs of data with GPS (you have a 60 minute periodic sync over cell, and a 3600 second GPS activiation). Normally the Notecard handles this just fine, but I like to stagger them a little more, like 75 minute sync over cell, just in case the GPS module is taking a long time to ascertain its position. It’s possible that syncs can be missed in this scenario. Alternatively you can try an external GPS entirely which will avoid these conflicts.

Thanks,
Rob

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Hello Rob,

It is quite unfortunate that the Notecarrier-A is not compatible with the Notecard Cell+WiFi. Thank you for bringing this to my attention; I did not know about this beforehand, so this saved me from a lot of future headache.

The staggered sensor reading and Notecard syncs is a nice idea I’ll definitely keep in mind.

Thank you!
Andy

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