Extra battery is useless - changing batterys mid game about never works.

[cate]

I got 2 of vives batteries for my wireless cosmos elite since just one battery with a mere 2 hours is bugger all. And welp the second battery is about useless especially so if you're playing multiplayer, because almost all of the time, when you change the batteries, the game will freeze, and steamvr wont pickup the headset until you restart vr and thus the game.

You're already pissed at this point that the shit battery is already dead (without any warning!!!), and despite you whopping out a hundred dollars to fix the issue, youll need to restart vr all over again. Which takes time and is a massive pain especially when software issues are bloody rampant. So instead of restarting vr to use the second battery, you'll go "Fuck this shit 😠 Never getting a stupid VIVE product again." then come to the forums to bitch about vive and its dogshit design and fucking infinite array of issues.