Nano 33 BLE Power and Battery Management Solution?

Hey everyone

I’m working on a hobby project to take some measurements throughout the day using my phone with the IMU on the Nano 33 BLE. I want to be able to power it with a battery as well as plug it in and charge it at night without having to pull the battery (like a cell phone). This is out of my wheelhouse - I’m more of a software guy and appreciate how easy the BLE is to work with. My end goal is to buy / build the Nano 33 BLE equivalent of something like this: Adafruit LiIon/LiPoly Backpack Add-On for Pro Trinket/ItsyBitsy : ID 2124 : $4.95 : Adafruit Industries, Unique & fun DIY electronics and kits

From what reading I’ve done on the forum it appears I can wire directly into the 3.3v, but that bypasses all the safety protections. It’s more efficient, but I’m not really worried about efficiency at this stage so much as getting a quick and effective solution in place. Any advice?

Edit Compactness is a priority, so using the existing usb port for a 5v battery won’t work. I need to keep it as tight as possible.

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I am in a similar position and have this question, too. Would love to see a response.


I opened your link and it states: "Charging is performed in three stages: first a preconditioning charge, then a constant-current fast charge and finally a constant-voltage trickle charge to keep the battery topped-up. The charge current is 100mA by default, so it will work with any size battery and USB port. If you want you can easily change it over to 500mA mode by soldering closed the jumper on the bottom, for when you'll only be charging batteries with 500mAh size or larger." That indicates to me the charger is built in and the battery does not have to be removed. I am not sure what you are asking but It appears to me you do not want to remove the battery.