Electron And Car Battery

This questions is about the Particle Electron Asset Tracker shield.
Am I able to connect the car battery directly to the Electron 12VDC terminal (blue terminal). See image below. I read the spec for the shield and it says 5 to 12 VDC.
Recognizing that the the car battery voltage is any where between 13.7 to 14.7VDC when the vehicle is running, and is usually above 12.6VDC.
If it cannot be connected to the car battery, is there other suggestions that I can employ? Maybe a buck convert or additional battery perhaps?

image

I wouldn’t directly connect it.
The nominal voltage range of the car battery is your least concern - you should be much more concerned about the transient voltage spikes during cranking which can go much higher.

Have a look here

What ScruffR said is correct. We do not recommend connecting a vehicle supply directly to an Electron or AssetTracker shield.

This application note is more geared toward Gen 3 devices (Boron), but would also work with the Electron and AssetTracker.

AN006-Vehicle-Power

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I picked up one of these step-down modules designed for automotive use a while back. Less than $10 on Amazon: https://www.amazon.com/gp/product/B01M03288J/ref=ppx_yo_dt_b_asin_title_o02_s01?ie=UTF8&psc=1

Just ordered on from Amazon.
I will test her out and see how it pans.

Does the asset tracker shield use the same voltage regulator as the relay shield?

You can look at the BOM in the open source repo :wink:

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I was just curious, because if so it should be able to handle up to 24vdc. I have a relay shield running off of 24v for several years now.

That might be, but even 24V wouldn’t suffice when directly connecting to the car’s power rail.

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Hi Dougal,

I bought the hardware you recommended and it did not work. We were applying 12.57VDC using the car battery as an input to the step-down module and the output we were getting is 0VDC.
The step-down module is right out of the box.
Any idea what we are doing wrong here?

@n1849778, It appears that you have a “bad one”.
I’ve used about 10 of these same modules with no problem yet.
I know that’s not a huge sample set.

@n1849778, you could try putting a load on the 5v output like an LED and resistor to see if the converter “wakes”.

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Tried putting an LED and the it did not wake up.
I have tried connecting the Electron and it did not work either.

I am just pondering. I am plying 12.57VDC. Do I have to apply at least 24VDC to get 5VDC?
For you case where you tried 10 of these deivces, were to connecting them to the 12VDC car battery?

@n1849778, the device should operate at 12v. You should disconnect everything but the LED and resistor (> 1K ohms) to the output. Make sure you have the correct polarity when connecting the LED.

Polarity in LED is correct and resister in series. No dice.
I think the converter is bad.
I have contacted Amazon for refund and have ordered another one.

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