Electric clocks run fast (AC200MAX)

Electric clocks plugged into household wall outlets that are powered by the AC200MAX as well as into the AC200MAX directly gain around 7-10 minutes PER DAY! Which is excessive. The same clocks run correctly when plugged into outlets that are directly connected to the public electric grid. :thinking:

But the date and time as shown in the upper right corner on the AC200MAX’s touch display are correct.

The AC200MAX’s settings are to USA standards of 120v 60Hz.

Perhaps Bluetti’s engineers can figure out this head scratcher and come up with a fix?

I don’t see why using power from AC200Max can possibly cause clocks to run fast. Clock speed should not be voltage or power frequency dependent should it?

I seem to remember reading a long time ago that clocks use the AC frequency of 60 Hz for their timing function. While battery powered clocks use a type of oscillation generator? Anyway, I can only test the voltage and not the frequency. My tests were conclusive as per my previous posting. Weird, right?

Many electric clocks take the AC frequency as timekeeping speed. If a battery powered generator is off with it’s frequency then it will affect the clock speed of clocks using this frequency.


Nice educational video. Thanks for posting it.

Thanks for the info.
You know, I don’t have any truly AC clocks. All my clocks are battery powered, or uses an AC - DC adapter.

there are 1440 minutes in 24 hours. so if you are 10 minutes off per day, the frequency is off by 10/1440 %, which is less than 1 % (actually 0.69%). if your clocks are fast, then the frequency of the inverter must be a tiny bit above 60 hz (60.4). interesting observation!

Those clocks are not affected by the AC frequency as they use DC which has no frequency.