Instructions for adding a second keypad

SS2 or SS3?

Sorry, I am unfamiliar with Simplisafe's nomenclature.  The base system was only purchased recently.  On the shipping invoice, the part number for the keypad is SSKP3W, so my guess is that this is an SS3.

You can add an additional keypad the same way you would add any other device to your system.

That's odd, I didn't have to do that.

So you add the 2nd keypad, and the base will populate all the sensor information to the new keypad?

I doubt it is stored "in the keypad".  More likely the keypad accesses the base when the list of sensors is brought up.

All you gotta do is go to the original keypad and go to add a device and select  ... keypad .... The system will tell you what to do from there.  Don't forget to pull the battery insulator.

My keypad doesn't work (doesn't come on even with new batteries) so I tried using the key fob.  It doesn't activate the system even after plugging it into the base.  Do I have to have a keypad for the system to arm?  I'm looking to add a door lock but may switch to another (Ring) system all together if I have to start from scratch.

If you can plug the key fob into the base, then you have SS2.  I don't think the lock works with SS2, but I don't have one to verify that.

The codes are stored in the account, not the keypad, so I can't see any way to have different codes for different keypads.