Printer Friendly Forum Posts - dei 520 battery backup

2001 chevy silverado, viper 5901 and remote start currently installing...

Hello. i have the 520t brain backup and the install instructions tell you to ground the module, hook up to 12v constant positve fused and then it tells you to connect the GREY positive output to the brain only.

A friend of mine is an installer and he told me it's fine to hook up the 520t's red + constant AND the GREY wire together to 12v constant vs just the grey wire to the brain. also, the 520t says not to use parking lights via the viper 5901 to run the truck's parking lights as the battery backup doesn't have enough juice.

i'm torn whether or not to install this now. i have a batter backup siren, so i know i don't REALLY need the 520t, but i like to cover all my bases. Should i leave it out of the equation as i intend to use parking lights for remote start. Or can i hook it up the way my install buddy says? i'm afraid to make a mistake.

please help me all. THANK YOU MUCH!!!

Bill

I would leave out the equation and hook it up to DEI specs. Just make sure the grey wire powers the alarm brain and siren only..and is not connected to power other devices or relays. If your parking lights draw to many amps (juice), you will want to switch program jumper to a neg setting and use a relay. I will be honest though, I am not impressed with the 520Ts. I have had a few in the past year and they don't hold a charge very long and the current that charges the battery is not regulated via the diode box..thus prematurely wearing down these batteries. I have decided to scrap the 520t and bought a UB1250 universal backup recharg battery for my alarm system. While it is somewhat bigger and might be harder to conceal, these last up to 3 years and can supply more amps...thus if you want your park lights to flash or even a second siren, this should get the job done. I bought a 12v 4ah battery. The reason for this is my alarm system draws just under 4amps during full activation, light flash and 2 sirens. So the way I look at it is it will supply 4amps for an hour if a thief cuts my power supply. I use the same diode box but added a resistor to limit the charging current into the backup battery. I cut the plug off the original backup battery and connected it to the new larger backup batt, and plugged it into the original harness that leads to the diode box. I know this is a little of the subject, but just thought I would share my thoughts.

ACTUALLY, it's a PERFECT response. unluss i do the mod you mention, i'll leave it out altogether. i was thinking along the same lines of the shortened life of the battery. and i'm also in the AZ desert heat, so it'll only die that much quicker.

thank you.

eh, can't edit yet...

how does the 520t work anyway? should seem straight-forward, but things hardly ever are. does the 520t module ONLY use its battery power when the vehicle's battery is disconnected and otherwise it's using the vehicle's battery? if so, then it will run all the parking lights and what not without an issue as it takes its own battery out of the equation.

i ask this because the manual says not to use parking lights with the 520t hooked up. OR, is it referring to never using the power features while only being powered by the 520t's battery? i don't know why this thing is so tough for me to figure out???

Well I happen to live in Az as well so I know heat does number on any kind of battery. The 520t will only supply power to the alarm system when the main battery is disconnected. The diode box just serves as a circuit to trigger the negative pulse to the alarm, and to open the circuit from the backup battery to run the current to your module. However, most vehicle charging systems run between 12.8 and 14.5 volts. This is where these batteries fault..the same with LED lights on cars. There are either no resistors or the resistor used does not handle the current... thus overcharging or driving too much current into it. That is why I believe these batts don't hold up very long. LED lights start flickering and eventually burn out..just as an example. The parking light flash when in positive jumper position relies on the on board relay of the alarm.. while switching to a neg jumper, to the best of my knowledge uses the vehicle relay. I suppose that is why the vehicle park lights won't flash when the battery is disconnected thus allowing the 520t to do its job. The main reason I am going with a different backup battery, is for higher amp output to drive my 2 sirens, piezo, strobe lights and park light flash if the battery is disconnected. I would just make sure when you buy a 520t it is for sure new and has not been sitting on a storage shelf for years. Hope you find my insight informative.

jcs091570 wrote:

I use the same diode box but added a resistor to limit the charging current into the backup battery. I cut the plug off the original backup battery and connected it to the new larger backup batt, and plugged it into the original harness that leads to the diode box. I know this is a little of the subject, but just thought I would share my thoughts.

Could you tell me the resistor you used and where you placed it? I really like this idea, I just ordered 2 of the UB1250's so I could set this up in my truck, and my wife's car.

Thanks,
Rich

I have the schematics and will see if I can scan and post them.. or post actual photos of the diode box with attached ohm resistor and diode placement. I will find out from my dad what type of resistor he used. Can also take pics of my install and post them when I am finished. It should be noted these batts will need to be placed somewhere concealed obviously, but yet somewhere where they won't be exposed to excess heat. I live in a hot climate so I am considering looking for something to wrap the battery in that insulates it from heat if that makes sense. Thank you for your interest.

The resistor used here is a 1/2 watt carbon composition resistor..1100ohms. Carbon or metal composition will work and can range between 1000 and 1500 ohms. This resistor will limit charging current to between 14.5 and 14.9 volts to the UB1250 backup battery and at no more than 1.7ah. The average discharge current under normal conditions will be between 13.6 and 13.8 volts. These figures and other stats relating to discharge characteristics and duration of discharge vs duration of current related to temperature can be found at www.upg.com and search model #UB1250. Looking at the picture I took of the circuitry.. I snipped the diode off CR2 and attached it to backup battery+ pin C2. This serves as the blocking diode for the current from the 12v battery of the car. The resistor which is soldered in parellel with the diode, allows a controlled current to charge the backup battery. So this is my little project and I hope to get the install done this week. I more or less posted to benefit anyone curious that enjoys electronics as much as I do. This project just gets down to the more technical aspects of my needs and alarm system which draws a little more amps than the average system. But at the same time trouble shoots the problem I have been having with the 520t. This is in no means to disrespect DEI products or those who use the 520t.

Many thanks to all who contributed on this post, I learned a couple of things today, the Cliffords we have here with battery back up, same manufacturerer, different DEI part number, if they are abused whilst alarm is on, they will only power themselves; no light flash, having said that if we get 3 years, great! In our climate it's corrosion of the circuits that contributes, also interested in the comment about the desert, I suppose "sealed for life" batteries are a real no no then? I thought it was only in damp/cold northern climates we had battery problems, i.e. the November goldrush for auto factors, so thanks for enlightening me guys.

The heat shortens the lifespan and performance of batteries period. Especially in cars. Or needless to say it is hard on them. They may say 4-5 battery but in reality here in the desert, you're lucky to get 2.5 years. I am trying the redtop optima battery for my car. And thus far in a year, no problems yet. I went through 2 520ts in less than a year on my alarm.

in my camaro, my red top optima lasted 2 years. in my silverado, my yellow top died in less than two...

above is a pic of my new backup battery. I clipped the blk/red wire harness off the old 520t and connected it to my new batt using .187 or 3/16th female spade connectors. This will now plug into the attached harness of the diode box previously pictured. I hooked it up for a trial run..disconnected my battery while the alarm was armed, and the alarm went off full power with both exterior sirens and internal piezo siren. My lights still flash as well... but I use LEDs for my parking lights which draw minimal current. Thanks for your interest.

CAN'T see the pic...can anyone else?

Apparently the images were removed.

anyway, how's it working thus far? any boiling batteries or anything of the sort?

I take it you are being sarcastic. I just finished the install tonight. I placed the back up battery in a cut-out of the foam padding under my back seat..which is also supported by a fireproof/heat type padding that rests on the base of the car to protect the pull out back seat/foam padding . I located it here since anywhere under my dash or center console gets hot..and is conspicuous. I extended the wiring along the side panel in looming, and tied it in to the connections at the diode box and junction plug...which is located in my pass kick panel. I tested the voltage of the backup batt and it rests at 12.8 volts. Armed the alarm, and disconnected the power supply at the battery and the alarm went off full power. If I can figure a way to shrink the pics.. I will re-post.

sarcastic, some, yes. kudos to you for getting it to work right. sometimes i tinker around with things and get failed results. things don't always work as we would hope. glad it's working for you. as for myself, i'm STILL debating what to do. may end up doing what you did or i may still just leave it out altogether. thanks jcs.

I re sized the pics and hope this works. Starting with pic 1 is the diode box from the 520t with modifications....followed by the PS1250 12v new battery which turned out to be 5ah...added heat shrink tubing over the female spade terminals for extra protection using the harness from the old backup battery end.. 3rd pic we have the cut-out I made under my back seat. The wiring was then extended along the side panel of my car in black looming..where it connects to the diode box in the kick panel. Of course the looming was later pushed down under the interior carpet to be hidden. I had an extra plug from another 520t that I placed at the kick panel so that I can easily disconnect this unit if I must. The wiring used was 14awg. Thanks for looking posted_image

Finished my install last week, the 520t doesn't seem to be doing it's job. I got it from amazon and I'm wondering if it has been sitting on the shelf for years. Can any one tell me where to find the manufacture date? I see on the package UPC it has: P/N 520T 7/03 Does that mean it was made in July 2003? What does your say there? Thanks!!

To the best of my knowledge that is the manufacturing date. I ad 3 separate 520s and they all had different numbers/dates. So these ones you buy off Ebay and Amazon have been overstock and sitting on the shelf for years. The only thing I could suggest is buying one brand new from DEI or local shop or doing what I did. If you have any Q's let me know.

The DEI tech I talked to said there should be an "OK" sticker on it with a date code like 9J meaning january 09 etc, and that the 7/03 on the UPC was just the revision date of the package printing. I didn't have any sticker on my battery, maybe it's so old it's before they started doing the stickers.

Ended up getting a different larger battery, and using it with the 520T. Seemed to work properly. I was on a 2 hour trip, and the alarm went off while I was driving, I hit the disarm, and the siren stopped. I went to check it out later that evening and the alarm didn't seem to respond at all. I disconnected the backup battery, and cut the power to the 520T, and then reconnected/enabled power. This seem to reset somehow and the alarm seemed to respond normally. About 24 hours later the alarm (Viper 5901)was not responding again, completely dead, I tried cutting/enabling power to the unit a few times but it still doesn't seem to respond. Fuse is good. Going to leave it over night and see what happens tomorrow. Hopefully the 5901 brain isn't ruined. Any Ideas? I wish I would have just got the battery powered siren instead of the POS 520T. :(

When I had a 520t hooked up previously I had a similiar issue where I disconnected the power to try and set off the backup battery and it kinda froze the alarm brain. So I disconnected the power all together and it was fine...basicly reset the system. But I am using the new battery from earlier in my posts and having no problems. The only thing I can think of is you may need to re assign your transmitter to that alarm brain. The fuse may be good but are you actually getting power? Possibly a loose connection between the power source and the alarm. Or you may have a ground wire that came loose or unattached to the chassis. If your alarm went off while driving there might have been a loose connection somewhere and the vibration of the vehicle may have caused it to reconnect and trigger. I would leave the backup battery out of the equation at this moment and retrace your work, connections and make sure those are correct. If you used butt connectors tug on the wires and make sure they are tightly crimped and making contact. Hopefully you didn't use t-taps. Once last thing you can try is make sure the remote battery is fully charged. Maybe take it out and reset the transmitter... and it wouldn't hurt to make sure your antenna is connected and not loose or the cable got crimped or cut somehow. The only thing I know about the 515r back up siren is they seem to have the same issues as the 520t/. Start with the basics and let me know what happens. Glad to help.

Haven't had a chance to run out and mess with this yet, but I'll answer some of your questions: Fuse good, (and power) I'll check for loose grounds. No butt connectors or t taps. Transmitter fully charged, tried the other one as well, even if the transmitter need to be relearned to the system, i think the alarm should still flash the led at least once when the ignition is turned on/of etc. I'll have to check to see if it is responsive to programming with the valet/led. Since the brain can recall all the settings even after complete power loss, I assume there must be a small backup battery in the unit somewhere? or a reset button like on most electronics, I'll have to try that as well. One weird thing, when I was checking the different voltage going in and out of the 520T, it seemed like it was passing voltage from the battery even though there was a 12v source coming in. And when I disconnected the incoming 12v source, it seemed that the battery was feeding back out 12v input wire with about 6v or so. I assume there is is supposed to be a diode in there to prevent any power from the battery feeding back into the vehicle. Maybe the module is faulty/fried. Are there any other backup battery solutions that people are using? maybe from a different brand of alarm that is more reliable and doesn't have the overcharging issues etc? Thanks again for all your help! I'll report back once I have time to look into this after work :)

Your back up battery is unable to maintain a charge. The ones I had problems with would show 12v , but once connected to the alarm system, they dropped below 6v. Definitely a faulty battery. I would take this unit out of the equation and hook the brain back up to constant 12v to the car for now.

The battery shows 12v out of the grey wire just fine, I'm saying that it also was putting out 6v of power on the wire that is supposed to be the 12v constant input from the vehicle.

Ok, it seems that the only thing I am able to do is turn the Valet mode on and off using the valet/led. All feature programing, remote learning routines, event history etc. are unavailable and unresponsive - no beeps, blinks, or anything else. I think my unit is shot :/

If the constant power wire in the vehicle is only showing 6v.. then it is connected to the wrong wire. Some power wires rest at 6v or so with ignition off..but once cranked and in run position it shows 12v. Some examples of these wires are door locks and power windows, air bag etc. However if you disconnect the cars 12v to the backup battery, and the power wire drops to 6v, then that tells me the backup battery cannot handle the current draw/hold a charge. Let me know what type of vehicle it is and I will look up the wire diagram. The red power wire from the alarm should be connected to the grey of the 520t, and the red from the 520t should be connected to the car battery or constant 12v.

I don't think you understand. lets say the 520T is hooked up to the backup battery but out of the vehicle completely. On the grey wire you have 12V on the red wire between the battery and the module you have 12v. and on the red wire that would hook up to the vehicle you have 6v of power leaking back out from the battery pack.

Ok I got it. If you are worried about current leaking out on that wire, you can place a diode with the band towards the module to allow current to only travel in one direction. This really shouldn't matter but you can do as a safety feature. Where did you get your alarm system? It could be the brain.

From Amazon, sigma enterprises, I'm now wondering, does anybody know how these alarm systems come packaged from DEI? is it supposed to be sealed, shrinkwraped, etc? mine didn't have any of that, I'm wondering if I was sold a refurbished or repaired unit that was supposed to be brand new...

Well either brand new or factory refurbished would be in original box. That is how all mine have been sent from ebay. I hope seller has a warranty or contact them and let them know you want your money..even if it cost 10$ to ship it back. Otherwise, you got taken by a bad seller and falsely advertising the product.

It was in the original box, but there was no kind of seal sticker/tape, or plastic shrink wrap.

Well who knows what they put in there. This could have been a previously returned item for the same problem you are now having. If it is brand new there should have been a sticker over the tab on the box. The seller should have said it was opened in new box or never opened etc. But like I said, it wouldn't hurt to double check all the connections and brainstorm it. It could always be something really simple or overlooked. But then again you sound competent and I would agree the unit is dead.