Norsk Battery w/ Helix 7G3N

I just got a Norsk 15 AH battery and installed it on my sonar unit about 2 weeks ago. Since then I’ve had it out 4 or 5 times. I’ve noticed that immediately after charging, the battery read 100%, but the unit reads something lower.
As I use it throughout the day, the battery % goes down very slow, while the % on the Helix drops much faster. Below are pictures of what it currently shows on each, and how I have the unit connected to the battery.

Has anyone had this problem as well, or know what might be causing it?

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Pat McShary just posted in another post that the battery meter on a Helix won’t read the same as the battery. He said you won’t be able to drain that battery in a day of fishing even with the unit on the brightest setting

Sweet, thanks, just found it