SpoodleMix:
If you are wondering if I will ever get to the point (solution), here it is. The diode is in backwards. That is it.The diode's only function is to block charging of the CR2032 from power off of VCC, not provide a charging circuit. The resistor is a current limiting resistor intended to take the load off of the diode.
The battery should provide power to VCC to keep the RTC running in case of a power failure. This is a one way job from the battery to VCC. The way the board is shipped from China, makes a power path from VCC to the battery, not the other way around.
If you reverse the diode, you will have full functionality of the RTC, including battery backup. Only problem is that the power LED will drain the battery quickly. If you want to remove or cut anything, reverse the diode and then remove the LED so your battery will last longer when the system power is off. Remember, just because someone manufactured it, it does not make it correct. This board is both a bad design along with bad manufacturing. But does work if you fix it.
I agree with the above explanation of SpoodleMix.
Someone thinks, I will be smart and has changed it without enough knowledge of electronics and batteries.
He thinks...., if the battery is empty, I lost the time setting.
Okay, I will use an LR2032 (chargeable battery) connect it to Vcc by a diode and resistor and it will be charged all the time.....
(As you can read in story of MrAl, that kind of battery needs an special charging circuit and not this simple one...)
Based on this thought before, the print layout was changed but still the wrong battery CR2032 (not chargeable) will be delivered.....) After a time, it explodes....
Read this also; The right RTC battery… – WoodUino.ca
THE BATTERY CR2032 SHOULD ONLY BE CONNECTED TO Vbat OF THE DS3231 AND NOTHING ELSE!
The correct solution is; (1000% SURE)
Connect battery CR2032 directly to Vbat of DS3231, remove diode and/or resistor and problem is solved.
Power consumption of DS3231 is very low so the time will run well for many years.
