2002 3.0 Taurus battery not holding charge jumps easily enough but need to jump everyday?

Your security system is a starter disable type system. You can usually jump the starter motor, for testing, to see if it will crank the engine, even if it will crank that doesn't mean it will start, probably won't if security system is involved.
There are safety issues with jumping the starter, you have to be sure tranny is in park or neutral and parking brake is set. Safety is your responsibility.
Unplug starter relay, use jumper wire on load side of relay between two terminals, the load side is that line with arrow head, one of those terminals is hot all the time.

You can try different key, nothing on key ring except that one key. Check for applicable trouble codes. To check codes yourself, at the least, you need an obd2 code reader that will read manufacturer specific codes as well as p0 codes.

Make sure you battery is fully charged before trying again. If it starts and drains again then you have an alternator that needs replaced. If it is fully charged and you still get nothing but a clicking then you need to replace the starter.

Your battery probably isn't holding enough of a charge. I bet if you get a new battery your problem will go away. Alternatively, it could be that your starter is going bad and you need the extra power to get it going, but my guess is the battery.

While the vehicl is running with a meter ,,check the voltage across the battery you should have 13.5 to 14 on the meter..You can have the battery load tested at autozone or advance for free..If the battery is bad and you keep jumping it off,,you will burn up the alternator ..Also when its running do you see a battery light come on,,thats a indication thats its not charging

Check your battery voltage when the car is not running. Check voltage again as someone else holds the key to START. Check voltage again after you've jump started it. First reading sould be about 12.5 to 13 volts. Second reading should be greater than 10 volts, and last reading should be 13.5 to 14.6 volts. If first two readings are low, your battery is not charged, or won't hold a charge (defective). if the 'while running' test is less than prescribed, then your alternator is not putting out enough voltage to charge your battery and should be replaced.

yes you can, just don't cross the cables, you may need to reset electronics radio clock and such

its likely the starter is bad , if you can , charge the
battery overnight , if its the same problem, starter.

either your battery has dead cells and wont take a charge or possibly your altenator is faulty

Have you checked your battery???
A bad battery will not hold a charge. When you jump it to start it it will then keep running on the power produced by your alternator.The alternator will be trying to charge your battery but will not be able to if your battery is bad.

#1 Clean your Battery Post's and Battery Cable Connections with a Metal Battery Cleaner Brush.
Make sure the Battery Cables are tightened enough.
I just did my neighbor's van and that was the only problem prohibiting it from starting. It was also inhibiting a proper recharge of the battery from the alternator.
#2 When "jumping": was it Post to Post or Negative to Engine Block and Positive to Post? If so then check your Ground wire going to the Engine Block. Remove and using a metal brush - clean both the wire and the connection spot.
#3 What Fault Code is showing?
#4 Starter Relay possibly faulty. However starting with a "jump" all but rules this out. It again points back the Battery.
#5 Battery may be holding a charge, however whats is the Voltage? Below 10.5 and there is not enough power to Start the vehicle.
Let me know if this helped, or if you have any additional information or questions. Feel free to contact me at FixYa.com!