I current have a 2013 for focus titanium which is a keyless start with the push to start and the battery inside the the key has recently finished. I have gone and replaced the battery myself and ensure it was the right ***** and the right way up but the vehicle is locked but the key seems as though it has disconnected from the vehicle and is no longer opening the vehicle although the battery has been replaced. I wanted advice on what steps to take moving forward. If I break the window will I be able to reprogram the key to the vehicle myself. I also checked the inside of the key for the physical metal key but it’s not present. Any advice would be helpful 

Hi Lamik. When you bought your car did you get 2 sets of keys? You should have at least one metal key. If you don't then your only option is to get an auto locksmith.

You then will have to get a new door lock so you have a metal key.

Doing that is cheaper than smashing a window etc etc.

28 minutes ago, Lamik said:

... I also checked the inside of the key for the physical metal key but it’s not present...

I have bought 'used' cars for over 30 years (having wised up to the cost of buying new). I have never bought one that did not come with ALL the original factory supplied keys. I know this sounds smug, but it's not meant to be.

A missing key to me just screams out carelessness, and if the owner can't supply all the keys, I'm not really interested in their car and walk away. It also leads to the situation that the poor OP finds themselves in. The cost in not only money, but time & inconvenience caused by a missing key for me just isn't worth it...

2 hours ago, Lamik said:

the key seems as though it has disconnected from the vehicle and is no longer opening the vehicle although the battery has been replaced.

Hi Lamik, back to basics !!!

The keyfob battery going flat or replacing the battery does not cause the keyfob and the car to become disconnected from one another. The usual, and I have to say very common problem these days is that the 'new' replacement battery is already partly flat. Use a digital multimeter  and check the battery is 3.30V. If it is less than 3.00V then it is dead.

I'm not sure what advantage breaking the window will be to you other than setting off the alarm. The doors can't be opened from the inside if they are dead locked which on a 2013 Focus Titanium they should be. Since you are missing the metal key blade you still wouldn't be able to do much other than climb through the broken window.

A competent locksmith can get into Any vehicle with the proven owners consent. 

I have tried 3 new batteries so far and am about to try w more but there is still no result there seems to be no communication to the car but there is the info light on the dash flashing in red.

Can you get underneath the vehicle with a multimeter?  I'm wondering whether the cars 12v battery has dropped very low rather than it being a keyfob issue.

The immobiliser light flashing doesn't mean there's enough charge for the central locking to operate.

Personally I would have a locksmith out to gain entry through the door barrel as has been suggested above.  Then you'll have the door open and know whether or not the 12v battery is good.  If you break a window the car will be left unsecured and may still not unlock if it was previously deadlocked, again as suggested above.

Would I be able to test the battery from underneath the car?

19 minutes ago, Lamik said:

I have tried 3 new batteries so far and am about to try w more...

All you need to do is test one battery and see if it's pushing out 3.3v, if so, it is not your keyfob battery. Otherwise, Toms advice is excellent,,,

1 hour ago, Lamik said:

Would I be able to test the battery from underneath the car?

Yes.  One probe to the starter or alternator cable.  The other to any piece of metal on chassis/engine/gearbox.

19 hours ago, unofix said:

Hi Lamik, back to basics !!!

The keyfob battery going flat or replacing the battery does not cause the keyfob and the car to become disconnected from one another. The usual, and I have to say very common problem these days is that the 'new' replacement battery is already partly flat. Use a digital multimeter  and check the battery is 3.30V. If it is less than 3.00V then it is dead.

I'm not sure what advantage breaking the window will be to you other than setting off the alarm. The doors can't be opened from the inside if they are dead locked which on a 2013 Focus Titanium they should be. Since you are missing the metal key blade you still wouldn't be able to do much other than climb through the broken window.

If I do break the window and open the bonnet to check and charge the battery will it connect?

2 minutes ago, Lamik said:

If I do break the window and open the bonnet to check and charge the battery will it connect?

Are you saying that the car battery is flat ?

There are ways to recharge the car battery externally from under the car with out the need to break windows.

4 minutes ago, Lamik said:

If I do break the window ...

You have more than a healthy obsession with smashing a window! You got something against getting a decent locksmith out to help you?

Try getting jump leads onto the starter motor terminal, connect them to a good battery or another car, will have enough power to open the doors then if the car battery is low.

If the keyfob is faulty or desynchronised, breaking a window may not help. 

You would have to put the fob in the emergency slot immediately and hope the immobiliser reads the transponder chip.  You will need to press the clutch to start the engine which won't be easy unless you dive in through the window.  Even then, that will only work if the car battery is good.  And we don't even know if the fob chip will be present seeing as the emergency blade isn't.  (Previous owner may have had the cheapest replacement fob possible - just the keyless part programmed)

When you eventually get the door open, replacing the door barrel should prevent this situation happening again .  Genuine Ford C-Max Grand Focus Mk3 Kuga Complete Vehicle Lockset 2010-15 1877073 | eBay

You can order one of these from your Ford dealer on Monday

2 minutes ago, unofix said:

You can order one of these from your Ford dealer on Monday

Aahhh... one of those new fangled car openers that don't need a battery 🤣