Hi, hoping someone can answer a quick question.

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Hi, hoping someone can answer a quick question. Got a DFRobot Beetle this week to learn to do wearables with my middle school students. Got my prototype running with the USB. Can I power the Beetle with two CR2032 coin cell batteries? Will this damage the device? What is everyone using to power their Beetle? Thanks

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Official doc says “6v will damage the product by overvoltage”, so I wouldn’t try it.

I’m using a single 18850 battery which is a bit bulky but is fine otherwise.

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While not as small as two coin cell batterys, a portable phone chargers will run your beetle and a number of LEDs for hours.

https://www.amazon.com/gp/product/B00AA6CS86
https://www.amazon.com/gp/product/B00CTK762E/

I use the Anker battery in the second link to power a 32 pixel strip I put on my backpack and it will run for 6+ hours (at a low brightness level).
https://plus.google.com/+MarcMillerTime/posts/ewcip311umN

Note that on the Beetle wiki page it specifically says 6V will damage the Beetle so keep that in mind. Ideally it wants 4.5 to 5V. It also says it might run on 3 to 4.5V but it could be unstable, so if you use two coin cell batteries it might work, but also might soon not work as the batteries are used up.

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You can look for 3.7v Li-Po batteries, something like this (a random find from Amazon just for the idea):
https://www.amazon.com/gp/aw/d/B011SHYQLW/

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If you are not time-constrained, I suggest ordering from China (eBay, AliExpress etc)

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I can also suggest using cheaper attiny85 based devices – they have less RAM and flash (borderline enough), but are nevertheless useful; I was just using one to drive a 60 led neopixel ring. They are about $1.3 to $2.1 each, depending on where you get them from.

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For example, https://www.amazon.com/gp/aw/d/B073VK7TYQ/

https://www.amazon.com/gp/aw/d/B01N0IGJD5/

Same from China on eBay is cheaper, if you can wait a few weeks

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Hi @Ascencion_Reyes - You might want to consider using the inexpensive AA Boost Module V2 from DFRobot. It can power the Beetle and your LEDs, too. See the following post by @Mark_Kriegsman :

https://plus.google.com/112916219338292742137/posts/4f9R6UB8Bdf

I have used them and it works well with the Beetle and RGB LEDs.

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As for 18650, there’s that nice shield available (which I just ordered), providing 5V, 3.3V, standard USB power output connector, as well as a controller to charge the battery from micro USB. This covers most scenarios to power small devices, so if the 18650 form factor is not too big for you, I’d definitely recommend it.

https://www.aliexpress.com/item/ESP32-ESP32S-For-Wemos-For-Raspberry-Pi-18650-Battery-Charge-Shield-Board-V3-Micro-USB-Port/32843629344.html

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Thank you all. This information is very helpful. I will definitely look and try each option.

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Sorry to bump up an old thread, but I just noticed one option has not been covered – that is, using a boost converter. So, for the sake of completeness, here it is.

You can use boost (step up) converter and either one or two AA (or AAA) batteries, which is probably the best option as AA/AAA are the most easily available batteries. Sure, you can just use three batteries and no converter at all.

A boost converter will raise the voltage from either 1.5 or 3 V to the required 5V, and its overhead is very low. You can also use batteries which are almost depleted, as the module will use the battery up to 100%.

Depending on the current you need, a single 1.5 V battery might not work (if it’s more than about 0.1 A).

Here’s one for example, costing you the whole $1
https://www.aliexpress.com/item/5V-DC-DC-Converter-Step-Up-Voltage-Regulator-1V-5V-to-5V-Power-Supply-DC-DC/32849252501.html

Another: https://www.aliexpress.com/item/NEW-0-9-5V-To-5V-DC-DC-Step-Up-Power-Module-step-Voltage-Boost-Converter/32832864503.html

There are similar modules for 3.3V, too, in case you need those.