While charging, the light bar on the Dualshock 4 pulses fast when the battery is low and fast when it's almost done. You might know a few of these things on the video but I bet there is at least 2 or 3 things here that will be new to you!
I'm confused, you say it pulses fast both when low and almost done? So how do I know it's still low or almost done?
Either way, I don't really care. I have two controllers and when one is empty I charge it and play with the other, I am focused on whatever game I'm playing and when I think about checking on the charging controller, it's already done!