NEX-6 battery - horrible :( - Any tips?

I have 2 third-party budget batteries. Both work in my old Nex 3, only one works in my Nex-5n.  I NEVER take a camera anywhere without at least one extra battery in my pocket.

When visiting Osaka in 2009, I missed all the neon signs (and other evening/night shots) because I ran out of (Panasonic Lumix) camera power around 3:00 in the afternoon. Though I did track down a spare battery on my second day in Osaka,  it was wet and rainy THAT night (and no good for picture taking.  I don't believe I've made the mistake of going single-battered into the world since then.

;~}