None of my horizontal coil cartos work on my 3.7(4.2) or higher volt batts/mods. I used to have an Elegant Easy XXL, which they worked perfectly on, but it died after only 2.5 months. It was 1300 mah, which was great but it had a major design flaw. I got it at Cigeasy and their designated CS rep informed me they were made by a different MF than their regular Elegant. Apparently, the wire that is soldered(sp?) to the underside of the center post is extremely fragile and has a tendency to detach, rendering the unit useless and unfixable. That's what happened to mine Can anybody recommend a high mah, reliable and well built alternative? It needs to be kr808 style, as I'm heavily invested in that style carto. TIA!