When ordered, backorder date was 9/10/18.
When 9/10/18 arrived, it changed to 9/20/18.
When 9/20/18 arrived, it changed to 10/5/18.
[Update 9/27/18: Before 10/5/18 arrived it changed to 10/12/18,21 days after BatteryShip's response, below, on 21 Sep that promised 7-10 days, and with no notification from BS again.]
Starting to guess I'll never see the product.
Order #BC*******521B******* for what it's worth.
No updates from BatteryShip. I need to keep trying to order a new item to see what the latest slipped date is.
Update 9/21/18
A couple hours after Paul's reply, below, he also contacted me by phone for a little in-the-moment fault-finding to help identify where e-mails are being lost between BatteryShip and Hotmail
Clive, thanks for your feedback and your patience on your backorder. I did email a letter to everyone last night (9/19/18) that had backordered this kindle voyage battery type. The letter explained the problem the factory was having getting the materials in order to make the battery (that email to you might have been caught in spam filters). The factory finally got the specific material for that battery from their supplier last week and so they were able to complete the batch of batteries this week. As my letter stated, we'll have them on hand within about 1 week from the factory and so your backorder will ship within about 7-10 days from now. Most of our backorders ship earlier than the estimated date shown on the website, but sometimes the factory has trouble getting certain rare materials and parts to make certain batteries like the kindle voyage battery. We are sorry the backorder estimated ship date was not accurate from the beginning on this particular battery. We did our best to inform all customers of the estimates we had based on what our factory was communicating to us each week. Thanks for your understanding on this.