I just purchased a new battery (XS D4900) to cure a starting issue. The starter wouldn't turn over and the breaks would freeze up. I still have his problem with the new battery. Even if the car sits for 24 hours, I have to jump start it. I do not get any warnings that show "low battery". Car operates normally after the jump (no warnings). Sorry picture is blurry - it says "Press brake to start." Thank you for your help.

 

Sounds like the car has a pretty big current drain somewhere?
Need to start looking and checking circuits.
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Use a sand paper to clean both the inner part of the battery cable terminal and see if it works. Bolt it to the battery posts but not too tight, as long as the terminals doesn't wiggle. Also look if there is a corrosion at the battery cable connection. Must have good grounding source from the car

 

Is this to make sure there is a full current?

 

I do have a radar detector plugged in. Additionally, I have an after market sub woofer and the amp is on standby. But I have had both products drain the battery and was never an issue until now.

 

If your vehicle says "Press brake to start" its just not detecting the brake pedal pressed.
Press harder, or if its no help, then replace the brake pedal switch.

 

This is "one of the step" you'll do if your car doesn't start despite of having a full charged battery. Do you have a multimeter? If you do, check the battery voltage before you start the car in the morning

 

I press as hard as I can and the brake "builds resistance" each time. Do you know where this switch is located?

 

If the car starts with jumper cables properly attached, the brake switch is working correctly; the starter wouldn't engage otherwise. Somewhere in the shop manual is the starting sequence for your car; I once bookmarked it, but can no longer find it. My point is, there are about a dozen things that must happen, in the proper order, for your XJ to start.
"Diagnosis by substitution" is frustrating, time-consuming and expensive. Do what a previous poster suggests; measure the voltage on the battery posts after allowing the car to sit overnight. You may have to raise the trunk lid the night before if the battery discharges below the mechanism threshold. You can buy a cheap multimeter for $7 from Harbor Freight if you don't have one.
Report back with your results, and the forum will offer subsequent suggestions.

 

Its in the footwell, up in the pedal arm. I suspect that this switch are playing up and do not make contact every time. Your brake lights should be lid when brake are pressed and only then its allowed to crank the engine.
By my experiense when battery have low output the dash display goes black/off and reboots when starting. (seen it few times when starting my diesel in -28C / -18F)

 

OP >>>> Go to any auto parts store like AutoZone, NAPA, O'Reiley's, AAP and have your car's battery and alternator tested. The test is free of charge