how long to charge 520t?

I just put a dei 520t battery backup on my alarm-python 990. How long does it need to charge for before it will work? Also someone said it won't have enough juice to run the parking lights, sirens, and horn. So how do I set it up to make my sirens keep going off when someone breaks into my car and disconnects the battery. I ask cause my neighbor just got his rims jacked and they just disconnected his battery to bypass his alarm. No one even heard it go off. So obviously it was a professional thief.

That would depend on how much power the alarm sends to the battery and how discharged it was. I would think an hour would do for most small batteries. the battery is 0.7amp/hr, I think it could run your parking lights and siren for a few seconds. However, I would pick up a 12v battery from radioshack or any commercial/residential alarm company or even a motor cycle battery if I was that concerned about it.

So what disconnect the small battery that came with the 520t and add a large 12v like car batter? How the hell would I hide that?

Also I hooked up the blue wire to my -blue input on my alarm, that is also hooked up to my trunk pin. Do I need to diode isolate it, or is it ok the with it just attached. I used a relay to change the cars trunk pin from a + to a negative.

No, they make 12v lead acid batteries that are 1/4 of the size of a small car battery. Going from memory, roughly 3"x4"x6", somewhat similar to what is in a computer uninteruptable power supply.

Well what the hell is the point of having a 520t if it doesn't have enough power to make the alarm go off if someone disconnects my battery. Guess I'm just screwed.

It can make it go off. I just think it doesn't supply enough current for long operation. 0.7Ahr capacity, I'd suspect the brain needs at least a full amp to trigger and sustain the siren. Figure four 5 watt bulbs, so 20 watts total for turn signals, that's almost 2 amps. Leading me to believe that lights and siren will cost you 3 amps minimum. At 3 amps, your roughly 4 times the Ahr output, so maybe 15 minutes of run at best. A single shorted filament could take that down to a chirp. With all of the leads, it looks like it is designed to be an add on module for alarms without the option for a B/U battery. With some diode isolation and possibly a charging circuit in the little box. My Alarm does have a separate pinout for a battery back up, so two wire would be all I needed, but I don't think this is a common feature for alarms. This part is probably for consumer to feel good more so then a professional option.

so how long should the backup battery make my alarm system go off for, if the battery is disconnected. I really only need it to go off for about 2-3 minutes. Because by then it will either scare the thieves away, or I will be out their with my bat to kick some ass.

Ok I think I got it figured out. I'm going to hook up the blue wire from the 520t to my alarms gray hood pin wire. Since if they open my hood or disable my battery it will show up on my pager as someone messing with my hood. I guess I will diode isolate it also. Also I guess since my parking lights are negative they wouldn't make any current draw on my alarm. So I should be good with the back up battery as far as it making everything work, till I can get outside to kick someones face in. I hate thieves

I wouldn't ground to the hood pin. If you only have one ground to the battery it will only be grounded when the hood pin is. I don't believe the battery will charge if the hood is closed and the pin is not grounded. I agree that since your parking lights are ground trigger that they will not work if your battery is cut. The alarm will send it a ground and not thing will happen since your car's battery will provide the voltage.