I asked what I could do to prevent this from happening again. They indicated it was likely due to over discharge. They recommended configuration settings to stop power output at 20% charge. However, they admitted this would still draw down the battery from idle draw.
I told them that I am using this for off grid solar, and my system was overdrawn due to idle draw (so that setting would not help me). They agreed and said I should keep an eye on the charge and not let it get to low.
In other words, these systems appear to be inappropriate for unattended off grid use. Unfortunately, I’ll need to rethink how I use these devices due to this major flaw.
after a few weeks, the support took some reaction of my call. but it don´t helped so much.
i tried following:
do nothing for 10-14 days to regenerate the battery cells
i tried to load one of the B300 with a external 12V - and after these days it worked !! but only with one of the two B300
i connected ac300 & both b300 in a daisy chain. the in the meantime regenerated and loaded b300 at the end. in detail: ac300 + empty b300 + half loaded b300
i turned on the external 230v-power supply to ac300 and: the drained b300 in the middle begun also to load.
my conclusion:
Bluetti-devices are NOT for standalone use with solar. you have to use always an external power supply to prevent a 100% drain.
this means, i have also to rethink my solar-concept. i´ll try to sell this stuff and look for alternatives beside bluetti.