I have replaced many parts in this car. Including the battery control module. But now car is getting drained of any juice if left sitting over 12 hours and will barely start. Anyone familiar with this problem? It's a 2014 Ford Focus SE

 

Some accessories when added on can cause problems like this.

Have you tried to unplug or disconnect any "add on" things you might have plugged in to your vehicle?

Some systems cannot go into sleep mode if an add on causes the system to remain active and result in battery drain problems after the vehicle is shut down and parked for the night.

 

What is considered add on? I have not added anything to the car. I bought a new battery and battery control module.

 

Almost all modules need to be programmed.

 

Something as simple as a phone adapter when left attached to the vehicle can in many cases cause drain problems.

Your vehicle has a network that consists of several modules. When the vehicle is shut down, those modules after approx 45 minutes go into what is called "Sleep mode".

When you approach your vehicle the remote is transmitting and the modules get up, prime the fuel system and get things ready for you to start the vehicle.

If the remote is left inside or close to the vehicle when parked, the modules DO NOT go into sleep mode and continue to draw power from the battery.
Could that be happening in this case ?

 

A BMS is a module so your PCM can communicate with, and throw DTCs (no check engine lights) when errors are detected.
Your old battery had a charging profile stored in nvm (non-volatile memory) inside your BMS like most smartphones as well as android head unit. When you changed out your old battery your old bms (without reprogramming) had no knowledge of the new battery change so the old charging profile would be used. Never forget there are people who buy a used battery because they can't afford a brand new one or they are selling the car.
Same can be said on a new battery and new BMS, your new BMS also doesn't have any knowledge whether you are replacing just the BMS alone or both, therefore you must reprogram it everytime you change battery or bms or both. If it's not programmed it's possible that your bms can discharge your new battery.

To program it you need a capable scanner like foxwell nt510 elite or use forscan. Without it you can program (reset) it with your high beam on/off several times and brake pedal in some sequences, search google to find out. There is no way you can reset your BMS by disconnecting your battery ground cable. Imagine everytime you take your car for service and the tech has to disconnect your ground cable and your bms gets reset, doesn't sound right. You reprogram it only once in a lifetime of the battery.

Before you reprogram it, you should use noco/ctek charger and full charge your battery so BMS agrees that your battery is new and not deeply discharged.