If your rice cooker has a timer function, chances are it will have an internal lithium battery to remember the time.
If it didn’t, then you would have to manually reset the time each and every time you unplugged your rice cooker – as in most annoying microwaves that simply blink 12:00. In other words, this battery affects both the time shown and the timer function, because the timer works based on the rice cooker clock.
This lithium battery inside the rice cooker is soldered on a circuit board.
Lifespan of this battery lasts anywhere between 4 and 7 years. If you have some soldering knowledge, you might be able to replace it yourself. (Bear in mind you will void the warranty if you choose this route. You could also damage your rice cooker.) Otherwise you will be stuck with the official repair centers for changing these batteries. Cost for everything is between $6 and $15 for the battery, plus $10 to $20 for the labor.
IMPORTANT: The rice cooker itself works perfectly without the battery. The only dead battery issue is having to reset the time manually if and when you want to use the timer function. I have seen my family using rice cookers since I was 9 (I am currently 35 as I write this) and neither them nor I have ever used the timer function. It is probably our lifestyle.
You could also leave your unit always plugged in. That helps to increase battery life because the clock function power will be provided by your home. On the other hand, then you will probably want a surge protector to avoid a bigger expense.
You can find below two examples of how this work could be done if you are curious and patient. The first uses no solder:
The second uses solder and even offers a way to replace the battery in the future:
In short, this lithium battery came to be in first place so people wouldn’t have to adjust the time after unplugging their rice cookers. Once it dies, it is not a big deal for most folks.
If you do need the timer function and want to replace the battery, the only cost for the DIY route is the battery itself ($2-3 at most) or $16-35 if you have it done in an official repair center.