My question is can I activate a second router (xfinity) on the same account?
And if I do will it deactivate the first one? ( currently using) ?
Many systems will not allow two modems to be used at one address. It's best to call in to see what the local policy is. Even if they do allow it you will need to pay for two accounts (twice what you are paying for HSI now).
to be totally honest I want it at a differant location ( my beach house) but I dont want to deactivate the one at my main house...