How is this an AB issue?
In fact I bet if you are low income and contact AB or your Audie they'd even have options to help cover the cost of the batteries. You may also be able to appeal the lack of coverage with an LMN etc.
Most of us go through about that amount in Hearing Aid batteries over a single year ... yes, it's expensive, but batteries are one of the many things that HA and CI users have to work into their budgets (just like people with contacts/glasses/bracing etc- not everything is going to be covered)
