How do I use the battle packs? I have 15 unopened ones. Do I just open them? How long do they last?

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Can surely open them in Battlelog,  but in game,  but escape to bring up the menu,  select balltpacks,  an down them.  Far as i can tell,  they don't expire if  unopened,  and went they give you,  you keep forever.  Well until you actually USE xp boosts.

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-- Of all the soles I've ever tasted, his had the most   ....cumin. --

They don't expire but they contain some useful perks. Some have upgrades to weapons ie grips, silencers etc. and some have 25%, 50% or 100% multiplier for xp points you earn in a match.

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