Dewalt 20V Lithium Ion to USB for easy swap rechargeable

Will a Dewalt 20VDC Lithium Ion to USB device work to allow occasional swap out of a battery in order to keep an electron alive for 3 months? Something like this:

I would still use the 1800 maH lipo connected to the Electron but then connect this dewalt battery to USB a USB cable.

What I like about this: 1) easy swap out with batteries already commonly used in my industry. 2) I get to avoid the cost of larger extended lipo batteries for customers without power by putting the burden on the customer to source the battery. 3) A person already frequents the area and swapping out a battery once a month would not be a big deal. By the way… the application would wake up every 30 minutes, take readings, publish an event and go back to deep sleep. This is in 10 - 50 degree F temps. With my initial limited testing, I can get about 1 week out of the 1800 maH battery that came with it. If I am thinking about it right a 20V 3,000 maH hour dewalt battery should get me ~16,000 maH at 3.7V . This should last me about 8 weeks (maybe less due to some leakage current. Has anyone tried something like this? Any reason this wouldn’t work?

I happen to have Dewalt 20V Li tools and this USB power adapter. I think it will likely work pretty well but you should know that at least one green LEDs on top of the 20V to USB adapter is always on when you are using it. This is not a big deal if you are charging your phone for an hour but could be a long-term battery drain for you of 10-30mA.

The Dewalt 20V Li batteries come in a variety of amp-hour ratings from 1.5 to 6 AH in the 20V type and in my experience are built from 18650 batteries inside. You have two voltage conversion from 20V --> 5V USB --> 3.3V so the efficiency will not be as good as if you had a single step down.

You should also know that these same batteries are marketed outside the USA as 18V Lithium since they are only 20V when not loaded.