Fishman pickups question power pack

Question for those who have a set of Fishman pups WITH THE POWERPACK.

When you charge the pack, and its green and you plug your guitar in, with a guitar cable do you still see the green light?

The light on my power pack flickers red, and I have to charge the pack for another 20m or so until it turns green… even though I barely used it…

Can anyone share their experience?