The same thing just happened to my board at 150 miles. The battery repair ends up costing 1/3 of the board cost. That’s a lot of money, they will not even acknowledge my ask for a discount.
I’ve now come to notice that they do not mention warranty on their website, or maybe it’s hidden and I can’t find it. There is no tab for warranty details as commonly found on product websites. So disappointing, I have recommended this board to two of my friends which resulted in them purchasing one. Will not be doing that anymore.