If you get genuine egos, they should last you several months at the least, unless you overcharge them. This is why I always recommend a lamp timer (for wall charging, I don't recommend charging off a computer at all) as often as possible. Makes it physically impossible to overcharge, since the power shuts off at however long you set it for. I would recommend stainless, as there's nothing to chip and flake off, and should stay looking nice for the life of the battery. The painted ones WILL chip and flake though.