Battery Back-Up Sirens

The Siren Test!

Battery Backup Sirens are a basic requirement for any 5 Star rated alarm. Being the part of the alarm that screams for your attention it is arguably the most important part of the alarm. I decided to put the major brands to the test to see how effective they are.

Before looking at the sirens I shall explain the different terms:

Digital Battery Backup Siren: These communicate with the alarm via a data wire so know if the alarm is armed or disarmed. As the siren knows the state of the alarm there is no need for an over-ride key so the siren can be hidden.

If the alarm is disarmed then the vehicle’s battery can be disconnected and the siren will not go off, this means that the Digital Battery backup siren is not only easier to live with but also offers a higher level of protection.

Basic Battery Backup Siren: These sirens trigger when they detect a negative or positive pulse input, They are cheaper to manufacture than Digital Battery Back-up Sirens and have no way of knowing if the alarm is armed or disarmed. Because of this disconnecting the power to them causes the siren to sound even if the alarm is disarmed. To get around this problem they have an over-ride key which will disable the siren. Due to this, the siren needs to be accessible which makes it vulnerable to attack.

The Battery Backup Siren Review…

Autowatch Siren

The Autowatch Siren is of the Digital Variety, hence it has no over-ride key to worry about and can be hidden for that extra level of protection. It has soft arm/disarm chirps or can be programmed to silent arming (actually silent arming isn’t strictly correct as it gives a very discreet blip). The Autowatch comes a very respectable second here. It is not as loud as the excellent Cobra and does not offer arm/disarm volume control.

Obsessive Rating 8/10

Apart from the Cobra the Autowatch puts the others to the sword!

AVS Siren

The AVS Siren is a data siren, this means that it cannot be tricked into being silenced by tampering with the wires as it does not rely on a negative or positive trigger wire. So whilst it is better than the Basic battery backup sirens found with Dynatron, Mongoose and Meridian it still has an override key and needs to be accessible. Despite the sales spin from AVS the siren is still easy to defeat and should not be confused with the digital sirens found with the Autowatch and Cobra alarms.

Obsessive Rating 3/10

Let down by over-ride key!

Cobra 4310 Siren

The Cobra 4310 is a true Digital Battery Backup siren. It is extremely solid and better still has a very high pitch sound. It is certainly the loudest and most attention-grabbing of the brands on offer here. The other great thing with the Cobra siren is that the Arm/Disarm chirps can be adjusted in volume to suit the owner.

The Cobra siren is so advanced that it will even give a diagnostic warning if it has been tampered with!

It’s also worth noting that the Cobra siren is waterproof.

Obsessive Rating 10/10

So good that the Obsessive Wagon has 2 of them!

Dynatron/Cyclops Siren

Dynatron Battery Back-Up SirenThe Dynatron Siren is a basic battery back-up siren with an over-ride key, Dynatron makes a large and a small version but both need to be placed in an accessible location for the over-ride key access.

As with the AVS, Mongoose and Meridian siren, this simply defeats the whole point of the siren being Battery Backup!

Obsessive Rating 2/10

Go for the 4 Star Dynatron -At least the siren can be hidden!


Meridian Siren

The Siren found on Meridian alarms is a basic Battery backup design, It is the same siren that is found on the old generation AVS alarms before they upgraded to the AVS data siren.

Whilst it is much better than the Meridian alarm that it comes with (probably because it made by someone else) it still isn’t very effective and is best avoided.

Obsessive Rating 2/10

More over-ride keys…..

Mongoose Siren

Mongoose Battery Back-up sirenThe Mongoose siren is another basic battery backup system with an override key. It comes with bullet connectors which is a concern as unplugging the trigger wire and grounding will it disabled the siren in seconds! The bullet connections really should be cut off and the wires soldered and taped.

The M60G siren can even be turned off without the key which is a worry!

Obsessive rating: 1/10

Would be 2/10 if not for the poor Bullet connectors!

This entry was posted in Alarm Accessories, Autowatch, AVS, Car Alarms, Cobra, Cyclops, Dynatron, Meridian, Mongoose, Reviews, Sirens. Bookmark the permalink.

20 Responses to Battery Back-Up Sirens

  1. Julian says:

    Don’t be fooled by the Mongoose website. The claim that their sirens are Digital are in my opinion very misleading. The bottom line is that all Mongoose battery back up sirens come with an over-ride key and therefor offer sod all protection!

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  4. Julian says:

    Here’s a “You Tube” video one of my customers has posted with a great recording of the Cobra Siren in action. Action kicks in @ 2 minutes and 50 seconds!

  5. Rick says:

    Presumably a digital backup siren will go off if its comms cable is cut while the system is armed? That seems like the whole point of a battery backup but just checking. 🙂

  6. Julian says:

    Hi Rick,

    Yes the siren will go off if it is armed and any of the cables are tampered with. If it is disarmed then you are OK to disconnect the battery, hence why I can hind them or make them difficult to get to.

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  11. Mike says:

    I have an AVS S5 Alarm, and I read your blog and find it really interesting, I was wondering if I wanted the Cobra decent siren, would it be compatible with my existing S5 system and could just be wired in? or is this not an option

  12. Julian says:

    Hi Mike,

    Unfortunately the Cobra Siren can only be hooked up to Cobra alarms. It communicates with the Cobra alarm module via a BUS communication wire.

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  15. Grant Geddes says:

    I have auto watch 555 clam! The siren would not shut up on this one occasion at the nice hotel underground car park! Very embarrassing, so in frustration I cut all 4 wires to the siren. Fixed the immediate problem but now what? Does anyone one know how to diagnose why the alarm went off to begin with? I can’t find any wiring diagrams on the net anywhere without password access.

  16. Julian says:

    Hi Grant,

    From your email address I gather that you are in Australia. If so touch base with Dynamco the Aus Importer for Autowatch.

    They should be able to offer you support over there.

    Sounds like your siren may have failed. Cutting all 4 wires should make the siren sound constantly. Autowatch sirens do not like getting wet so that maybe the cause but without looking I can only guess!

  17. Daniel says:

    Interesting about the digital sirens – offers some advantage.
    Really don’t really agree with the Mongoose bullet connector comment though (yes, I have a Mongoose). At the end of the day, the siren wires should be taped up and cable tied, so access to bullet connectors is harder than just cutting all the wires to the sire, which is how a burglar will deal with other non bullet connector sirens anyway.
    Just a thought for securing keyed sirens – hide it in one of the front guards, with just the keyswitch poking through a drilled hole into the engine bay. Problem solved.
    All the same, will definitely consider a digital siren system next time round provided the price is no more than $20 more (the driver circuit would cost a dollars, maybe even cents more to manufacture..).

  18. Julian says:

    Hi Daniel,

    In an ideal world the bullet connectors should be cut of and the wires soldered together then taped. Mongoose clearly have other ideas otherwise they would not come with bullet connectors!

    Your idea about drilling a hole in the engine bay to access the key hole is trying to find a solution to a problem that is better solved by purchasing a decent system. It’s a lot of cocking around that’s going to take time and would only work with certain vehicles plus is still a compromise.

    If you can produce a siren driver circuit that can work with a digital battery back-up siren for dollars or cents then great, go for it. Let me know as and when as I’m sure there would be a market for people wanting to upgrade sirens.

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