According to the display, the battery came with 88% charge. The first time it was charged, everything went well. The second time, it hung for hours at 86% - on the solar panel in full sun. Then I connected it to the power to rule out the possibility that the (also new) solar panel was not working correctly. There it continued at 86% for some time. Coincidentally, I came to see the display jump from 86 to 87, 88, 89, 90, ... within about a minute. up to 100%.
You could hardly pronounce the percentage before the next higher one was displayed.
Yesterday, things got even worse: I was hooked up to the solar panel in full sun. Before, it had been hanging at 74% for "ages", then it jumped from 74% to 100% within half an hour. My feeling is: if the charge is not increased within a certain time, the display then shows 100% very quickly to reassure the user.
My conclusion: At first the battery had a max. capacity of 86% and now after almost 4 weeks it has dropped to 74%/75% (?). Then the capacity is down to 0% by Christmas ???
