This is not only with their LiFe packs, this is about all of their batteries including lipo.

It is not uncommon for Hobbyking to send out a faulty pack so always check your packs as soon as they arrive. Make sure you enter the warranty code immediately and don't be afraid to demand a replacement or money back if it is faulty. But once they've gone in a robot you have no hope of getting a refund. Check before use.

That said, with all the LiFe packs we've bought from them (3S and 5S packs) I so far have not had a single problem with them and all came in well balanced on storage charge.

edit: And I've never had a problem with their Turnigy Nanotech racingpacks either.