I have a 4 year old Yeti 400 Lithium.
For the past year, it won't charge past 70%; either when charging from AC, or from DC.
I've tried resetting the display (hold unit + info button for several seconds).
Can you tells us about how you use the Yeti? Do you use it everyday? If you do not use it much maybe try cycling it from 70% to 40% about 3-4 times.
I used the Yeti 400 Lithium about a dozen times prior to covid. It's been sitting around for the past few years. Perhaps the non-use , or extended period plugged in, had a detrimental effect on the battery chemistry (I thought Lithium wouldn't have such issues).
I will try the discharge/charge cycle a few times this weekend and report back. Thanks for your interest and time.
I tried several charge/discharge cycles, but the issue remains. I was hoping that Goal Zero support would be on these boards; but it appears they are not. I will submit a help desk ticket and post the results here.