I don't think it's just the batteries, the whole economic model makes no sense. First, they're expensive - they need to be built for commercial use, so they're $500+ each. Second, demand is massively inefificent, a hundred thousand people want to travel from the train station to their office in the morning, and then back in the evening. Either you pay someone to keep riding the scooters back to the train station in the morning during commuting hours, or you accept that their utilization is going to be woeful. Thirdly, the MTBBTITR (Mean Time Between Being Thrown in The River) is 2 days, so you end up replacing your entire inventory every 2 days.
So, we need to hire a full time worker per scooter to return it to where it's needed constantly, we need to replace the scooter every 2 days, and they're $500 each. So it costs the company about $300 a day to run 1 scooter, so they need to charge about $100 per journey. Unsurprisingly, the demand is highly elastic.
The numbers are a bit facetious, but you get my point.