Garmin 965 not Charging until 100%

I had some issues I'm the 1st few charges after I bought it, but then it was ok for a year. But yesterday I saw it was 90% after a long time charging (which is ok) but then just a few minutes later it showed 100, which is strange 'cause usually it slows even more above 90%.

Garmin-Sierra can you tell us how long it should take according to Garmin to charge fr965 from 0% to 100%? I'm asking this because it takes much longer than my sons' fr245 and fr55 or my old fenix6.

1, 2. I'm at 81% now, so I'll be able to respond only in about a week+

3. yes

4, yes

1. Never been to 4-5h. Always stopped after 2h30/3h max as my Fenix 3 and the Venus 3S of my GF were charged after 1h or so. After 2h30/3h, the watch is stuck around 86/90%. Went to 95% once. Decrease to 89% around as soon as it is unplugged. 

2. Depending of the activities I do (5-6 times a week 40 min to 1h running with GPS). Around 15-17 days I would say.
3. Yes

4. Yes

I would say it takes almost two hours, where the last 10% are much slower.

And as I wrote above, a couple of times I've used an USB current meter while charging, and can see that the watch continues to charge for quite some time after displaying 100%, so I let it sit another extra hour from time to time.

1. I'll let it drain to 0% over the coming days,.
2. I'll update you when I know
3. Yes
4. Yes

Wow, 2 weeks with ~5 hours of GPS/week! Which watchface do you use? 

Easy round. I don't get what you mean. It's a lot or is it a little ?

Thanks for looking at this.

1+2) Have 83% and it says 21 days left, will update later

3+4) Yes, of course

Update: 1) shows 100%

Had 18% of battery today when I decided to charge it for the coming days.

It charged to 100% in one shot in 2h20 on a charger. Usually I charge it on a computer as suggested. 

It lasted of course less than 15-17 days the watch can achieve with my activities since it remained 18% battery. I would say it lasted 12 or 13 days.