I have problem with FIOS battery. Last time I called was on hold for more than 23 mins. They could not get my account number because they system was very slow. Right now I am waiting for last 40 mins and just music ... Dont know what to do 😞
Sometimes there is a bit of a hold time, you should try to have your bill handy when calling places like that.
In general though most, if not all, your answers regarding the battery can be found here.