This is already written under FAQ
So it’s upto 6 hours with ANC/Ambient on, 8 hours normal mode.
I’ve read elsewhere this is at 50% volume and I’m not clear if with LDAC 990 which on other buds takes 1/3rd power drain or not. Until you get a full answer, I’d assume to take an additional 1/3rd off the with ANC figure i.e. 4 hours LDAC 990 50% volume. As there are so many options and combinations, this probably needs owners feedback to be sure. I doubt Soundcore can answer every combination.
e.g. the above will be part of the early adopters who can give more precise battery life measurements for their combination use, noting to do a full battery benchmark can take weeks to go through each combination. Imagine you got technically superior Android, which can do LDAC 990 vs technically inferior Apple products which can only do AAC. So an Android user may report worse battery life because their audio quality is superior to an iphone’s owner.