18650 lithium battery circuit protection board must be it?

Want to make a LED flashlight, bought a section 18650 lithium battery, listen to the manufacturers of the battery that must be circuit protection board, do not know what to do if there is any adverse reflection, the impact will be great?
18650 lithium battery with battery protection board and without protection board, the difference is as follows:
1, without the board of the battery is 65mm height, plus the board is 69-71mm.
2, discharge to 2.0V, if the battery to 2.4V will not discharge, indicating there is a protection board.
3, touch the positive and negative levels, if there is no reflection of the battery after 10 seconds shows that there is a protection board, the battery is hot, then there is no protection board.
Note: The third test is not a professional. Do not experiment like this because it may cause a powerful explosion and cause irreversible personal harm, especially those poor quality batteries.
This is a question sent by a friend. In fact, it can be seen that the battery must be protected by a lithium battery protection board. The single-cell lithium battery protection IC uses HY2110 and HY2111. The dual-cell lithium battery protection IC uses HY2120, especially the battery. The group must also add a balanced IC, also called an equalization IC, such as the HY2213-BB3A.