** Edited as I failed to read the OP thread properly it would seem and didnt click the link The 1300mah ego battery is totally different in body shape to the X6 that I was explaining, based on the mention of the X6 charger. It's late/early and I have been looking at code all day is my excuse**
The X6's come with their own specific chargers when you order them, as already mentioned they have a slightly longer 510 stem which protrudes out of the casing a touch in order to make contact with the X6. The problem is that the X6 comes with a big, deep juice well so a standard eGo charger will not work. They shouldn't have sold you it without pointing it out though.
Personally, I think they are great and offer a decent level of adjustability for those who don't want a mech or full blown VV/VW mod just to bump up the power a little as required, the issue for me though is they cost a fair bit more than basic ego's and that is reflected in the price you have to sell them at, with the name eGo they are just assumed to be a slightly more powerful starter battery and often overlooked. Unfortunately as seems has happened in this case, you get people on ebay trying to get them out as cheaply as they can rather than offering the service and backup with it or even ensuring that the charger comes with it