Can a Lithium Polymer battery charging circuit on Arduino boards also charge Lithium Lion batteries? I have a project that the form factor of 18650 batteries works well for. The board I'm using is a esp32 based board with built in battery charging:
https://www.amazon.com/gp/product/B072HBW53G/ref=ppx_yo_dt_b_asin_title_o00_s02?ie=UTF8&amp;psc=1


I've heard that the flatpack type Lithium Polymer batteries have built in over charge circuitry. Is this generally true?
Can I directly charge a 18650 battery from Arduino type boards that have built in battery charging functionality? 


EDIT:  So from looking at the battery circuit schematic from the Wemos link and the board itself it uses a TP4054 "Standalone Linear Li-lon Battery Charger with Thermal Regulation in SOT".  And since I can confirm the board works with 3.7V batteries and my 18650 is a 3.7V type I think I'm good.

EDIT:  Found info on this board:
http://www.raspberrypiwiki.com/index.php/WEMOS_ESP32_Board_with_OLED

Also by "Arduino type" boards I mean any popular micro controller board that has a battery charging function such as the Adafruit feather boards. 

EDIT:  To clarify:
Reading here Li Poly and Li Ion batteries are essentially the same 
https://scottiestech.info/2015/06/21/lithium-polymer-vs-lithium-ion-batteries-whats-the-deal/

I believe the board is a Wemos D32 with an attached display though I can't find any specific info on this exact board.
https://wiki.wemos.cc/products:d32:d32#technical_specs

I basically want to know if I can charge a Lithium Ion battery with this type of board.  As this is potentially a safety concern I wanted to ask some experts.
There are Lead based, Nickel-based and Lithium-based batteries (there are actually more, but these ones are the most popular). Each need a different charger, but since lithium polymer and lithium ion are in the same group, it should work but I don't have the option to test it out for you.

Q1: Not every battery has a built in over- and undercharge function. Some do, some don't. To find out if yours does, if the internet can't help, tear it apart (be extremely careful about it).

Q2: Depends what you mean by " built in battery charging functionality". If that includes the over- and undercharge functionality, then it will work (tested).

Looking at the board (https://wiki.wemos.cc/products:d32:d32#technical_specs) it seems doable. 

The most important thing is to check, if the supported voltage of the li ion battery equals the supported voltage of the li polymer battery that can be charged with the li polymer charger. Since it says 3.7V on the data sheet, don't get a li ion battery with 3.7V+