Connecting a battery, charger and functioning circuit at the same time

Hi

I am building a circuit to power a MKR1010 Wifi board to transmit temperature data. This board will be held inside a spinning hub that ideally, wouldn't be regularly accessed, except for by using a charging cable. What I want to know and try to do is to have a LiPo battery to power the board and an intermediate board that will have either a micro usb port or alternatively a LiPo battery port that would allow me to attach a charging cable when the battery was low. The main point is that the battery should be unaccessible directly, unless I want to take apart the hub which would be a nightmare to have to do regularly.

So my question is really, does anyone know of a board that would allow the connection of a charger, whilst being connected to the main circuit and battery at the same time? Or alternatively if there are any posts related to this that talk about the building of one?

The MKR board doesn't need to be on whilst charging by the way.

Any help would be super useful. Thanks.

Update:

I have managed to find a board which does what I need, although it is no longer made(see below). I'm also unsure as to whether it is appropriate. The Thermocouple amplifier board will draw a maximum of 1.5mA at 3.3V. Does anyone know how much current the MKR board will draw whilst using Wifi to transmit the data. I know it's probably quite hard to know what this would be exactly. But an approximation would be very helpful. If it's less than 200mA then this will be fine.

This is a board and almost the same set up as I want to have for the power supply: https://www.sparkfun.com/tutorials/379

use this with this. these two items should give you the required result. here is a project which uses these. |500x333

hope this helps!

From https://store.arduino.cc/mkr-wifi-1010

Its USB port can be used to supply power (5V) to the board. It has a Li-Po charging circuit that allows the Arduino MKR WIFI 1010 to run on battery power or an external 5 volt source, charging the Li-Po battery while running on external power. Switching from one source to the other is done automatically.

To me, this sounds like the MKR WiFi 1010 already has the functionality you want. Maybe I misunderstand your requirements.