[Edit] Just read carefully, you are interested in battery. I was banging on about the standard Elite Strap.
I have tried two of the highly recommended after market ones (elite syle and halo style) and have the elite strap. I think the Elite strap is highly over-rated.
That said, I actually didn't hate the vanilla strap. But I took lots of time sussing it out e.g. how to angle the arms, how low on the back of the head.
I actually prefer vanilla for short periods of gaming and for watching movies I really think it is the best. It's light and you can lie back in the chair. BUT I start feeling pressure on my forehead after about 45 minutes and that doesn't go away.
The elite strap doesn't feel as secure, there is a tiny wobble when you shake your head. However, after a while I do forget I am wearing it. I could game for ages.