The answer is no, when I change batteries or take them out to charge I do not lose my custom program settings.
And I'll just add my comment that I think some people get carried away with too much notching. Notch discrimination can help eliminate hearing some trash, but it also rejects a lot of good targets that, for various reasons, fall in that rejected Notch window.
My custom program for example with the 5 by 8 double D coil, which is really good for trashier environments, is to accept all segments except the first two. And with that model, my custom setting was done using the jewelry mode because I like the recovery speed it has.
Then when I'm out detecting it just takes a small mental note to remember that most u.s. nickels ring up 12 or 13, and most of the better hire conductive coins display anything from 19 on up.
So rather than use a nothing system, if I am coin hunting specifically, I recover the 1213 readings and everything from 19 up. But I still hear the other targets that responded in all those other segments, and I like to hear those because sometimes some Target masking will degrade a Target and have it read lower, or at times read higher. I have recovered u.s. nickels that lock on 14 and most of those wer the u.s. silver war nickel minted during World War II. There were also a couple of nickels that rang up and jump back and forth between 11 and 12. I have also recovered older pennies, such as Indian heads and very early wheat pennies, that gave me an 18 or occasionally a 17 VDI read–out.
Anyway for the extra comments there's no charge but the answer to your question is no, my V-540 saves the programs during battery change or recharge.
Monte