DS1302 two minutes delays after 7 days

[arshidkv12]

IC: Ds1302
Two minutes fast after 7 days.
How to fix it?

[Makuna]

Need more details or explanation.
What do you mean by "two minute delays"? Do you mean you notice that the time returned from the RTC is incorrect and slow by two minutes over the period of 7 days?

The DS1302 is not a very time accurate RTC. At best it loses several seconds a day, at worse it can lose several minutes per day. It is very temperature sensitive. Newer chips like the DS3231 include temperature compensation and are usually accurate to several seconds per month.

[arshidkv12]

Sorry... It's running 2 minutes ahead within the last 7 days. It's being powered by a 5V HiLink SMPS and a 3V cell.

[arshidkv12]

How to improve accuracy?

[arshidkv12]

What is an affordable IC similar to the DS1302?
Decrease by 2 minutes after a 7-day period. What do you think?

[Makuna]

https://edadocs.software.keysight.com/kkbopen/timebase-inaccuracy-and-its-overall-effect-on-measurement-accuracy-588265262.html
DS3231/DS3232/DS3234
Accuracy ±2ppm from 0°C to +40°C
Accuracy ±3.5ppm from -40°C to +85°C
DS3231 is usually the next step up.

[arshidkv12]

Is the PCF8563/BM8563 more precise?

[Makuna]

it states 0.2ppm, but it doesn't have a temperature compensation that I know of. I have never tested it myself though.