DS3231 RTC - Ebay Experiances

[steve001]

Morning All

Thought i would share my experiences with one of these items -.

I purchased 2 of these some time ago, and decided to get them out again to try and finish a clock project that i have been working on for some time.

After compiling a simple test flow chart, i decided to leave my project running to test its time keeping accuracy and watch some television and have some lunch. During this period Wifey heard a "pop" shortly followed by the smoke alarm going off in the back room where i have my office.

After rushing upstairs and looking at what had happened, found this module had failed the battery had split goo everywhere and lots of blue magical smoke. Bewildered to what had happened found some tracks on the board had blown off / over heated and some component's had blown and the battery holder was a bit soft due to the heat. After realizing what had happened with the battery looked a bit further.

Worryingly found that the battery fitted was a CR2032 - this is a not rechargeable battery. This module has a charging circuit to recharge a coil cell.

After a bit of googling found that this battery should be a LIR2032. Whilst googling i also found that there are a few of these boards in circulation on ebay and amazon and they have suffered the same fate and the charging circuit is a simple resistor and diode from the 5V - not the best.

Correct Battery -

LIR2032.JPG (11.9 KiB) Viewed 3195 times

Please be careful and vigilant when leaving items on a soak test and if you have one of these modules check the battery.
The correct battery is as much as i paid the the Module

I have the joy now of wifey enjoying that she insisted on a smoke alarm in that room when it was made into a better office environment following covid and working from home.

Steve

[jgu1]

Hi Steve!

Thank you for sharing. Have I never thought about, must have checked my projects with this module

Jorgen.

[steve001]

hi Jorgen,

To be honest its something i never gave a second thought to either, have left all sorts switched on on a soak test unattended.
It was on for about 2 hours before it failed it wasn't instantly.

Just probably unlucky with a rouge supplier from china - some choice words came out later to describe them ..
I posted to make people aware and to check them before something awful happens as they seam to be popular

Steve

[medelec35]

Thanks, Steve.
That is very useful information, thanks for sharing.
You all were lucky, there was not a fire!
The situation could have been a lot worse.
I have bought DS3231 modules before & it's easy to assume everything is correct.
It's definitely something I will be looking out for when I need to purchase more.
It might be a good idea to wire a smoke detector to a relay that cuts the power to items being soak tested?

[steve001]

Hi Martin

Thank you

It might be a good idea to wire a smoke detector to a relay that cuts the power to items being soak tested?

This is something we have at work in the Test Area's - never thought i would need it at home - but definitely worth a thought
I have a separate supply to my bench sockets that is fed from a 10mA RCBO (much less than the normal 30 mA) it could be Easley integrated to it
Maybe an EPO button (Emergency Power off) or an isolator somewhere

Steve