Exactly, the market he is trying to serve has the customer as his own competitor. That is a bad position to be in. I wouldn't want to be my own customer, would you?
Two recommendations.
1) Go wireless with enough power for like 500 screen updates for 6 weeks between recharges.
2) Find a market where your customers can't make the product
https://us.kobobooks.com/collections/ereaders/products/certi...
Kobos are fairly hackable, and I suspect one could program a Kobo to do the same as what he is doing.