The notice works well, I do the same. Most airlines do allow Lipo packs, you just have to read the (very) fine print and each airline is a bit different. I flew four packs to the UK on Etihad this year and they didn't have a problem. Their rules state the maximum number of watt-hours for the packs and that they have to be in checked luggage. I took a print-out off their web site when I checked the bags in and they just put a fragile sticker on the case.