Is my Instinct Solar battery usage normal?

I really don’t think it is.  Okay when fully charged it’ll say 24D but never anywhere near that, I go off percentage.

So I use GPS about 4-5 times per week up to 45 mins.  Everything else on as standard.

I fully charged Sunday evening,  at moment Weds morning I’m at 40%, I predict it’ll need charged some time Friday.  

When I compare this to my old Forerunner 55.  I charged it on Sunday, went on holiday, came home Thursday morning battery 65% and that’s with quite a bit of hiking.  

So I’m not getting anywhere near 24D, maybe 6 at a push.  I’ve been on to Garmin support who told me to charge fully overnight which I did which didn’t make any difference, they also said I could return for replacement but easier just returning back to Amazon as faulty if it is, does this battery usage sound about right?