A message "very low" after waking up laptop

I have never seen this before and this is the first time I have seen it
It appeared for half a second so I am not 100% sure if that's what it was saying

Any ideas?
I tried putting it to sleep and waking it up again but the message did not appear

Possibility of a low power state of the battery charge?

The power was never unplugged since day1 and correctly the battery is at 93%