Battery replacement Siren unit Scorpion alarm

Mozza,a fellow owner of an 'A' Class has kindly forwarded these photos of the scorpion alarm siren unit which is fitted with rechargeable batteries, when these fail the LED on the dash will continue to flash for a given number of flashes as indicated in the diagnostic information sheet, every time the car is started and while being driven.
In Mozza case the siren unit could be taken apart, in fact it may well have been opened by the previous owner, as the neck where the cables enters the siren had been sealed with silcone and not shrink tube as is the case with the untouched scorpion unit.

On later car's it may be found that the two half's of the casing are so firmly fitted that the appear to be welded, on my 2002 model this is the case but the casing is in two parts but very very firmly fitted making it impossable without damage to open the casing even when warm.

Replacement siren units, complete with batteries pre-installed can still be obtained from Scorpion, albeit the alarm is no longer in production, please use this link for Scorpion web site and details.

Today Varta have been back in contact and we are now looking at another company that MAY be able to supply the triple pack Varta battery as fitted by scorpion however the cost for the 6 batteries in the casing as fitted at present would be approx 17.00

However before committing the Company prepared to assist with batteries I thought I would check out the problems associated with changing them, as I know that at least one member of has not been able to open the casing to access the batteries.
Because I'm familiure with the procedure for accessing the Activated carbon filter, it only took about ten minute to reach and remove the siren unit.

However even after having removed the two casing screws which are obscured behind the incapsulated nuts for the torx screws, I like wise was unable to undo the casing.
I suspect that had I cut and peeled the shrink tube surrounding the cable and loom I MAY have been able to split the casing, but i can't be sure and it certainly is a precise fit.
Another point did cross my mind, if I replace the battery with other than the original parts, I may well invalidate the certificate of approval issued in respect of this alarm system. At present my insuance Company insure the car on the basis of it having an approved alarm/imobiliser would this cause problems?

To have replaced the siren unit with manufactures component parts would have taken me a further 20 mins max, that basically means that I could have replaced the alarm siren unit for a max of 40(Uk) in 30mins and would not have possible invalidated the alarm certification, or caused problems with my insureres.

It was also an interesting exercise throughout because the specification for the Varta batteries installed in the alarm siren unit gives them a life of 5-6 years on trickle charge, which of course they are all the while the engine is running, therefore 40 divided by 6 or even 5 years = 8.00 per annum. I've decided I can live with that and will be replacing the siren as a unit complete with batteries when the time comes to replace it. That would then give me a further 6 years of trouble free motoring and security failing other problems with the alarm.

I will not be asking the Company to produce batteries as the task overall is not simple and because of the possible insurance cover problems.

Still want to try and replace your batteries then I'm sure the information kindly supplied by Mozza will asist you with the task.

Once the alarm has been accessed and the siren unit removed the rest of the procedure is simple.
The two screws in the rear of the unit which are hidden by the torx bolts have to be removed then the unit will pull apart - please note that the rubber o-ring seal that keeps the water out may well be fusing both half's of the unit together, care and patience needed but it will prise apart.

Next remove the two arrowed wiring plugs from the circuit board (the black plug, two wires go to the backup battery but both plugs need to be removed to aid access and ease of handling.

Now the unit is in two half's access to the battery is easy - simply remove the screw from the middle of the backup battery pack and prise the battery out from the adhesive pads it rests on. The other ends of the two wires are connected to the batteries with conductive adhesive paste that is available from MaplinsLofty:- I have contacted Maplins, they cannot supply the battery as a unit but may well ahve the conductive adhesive tape..

The battery is a VARTA 6/V250H Ni-MH battery 7.2v 250mAh, pictures attached of it taken out and stripped down for detail.V6 of the battery code apparently indicates there are 6 batteries in the assembly.
They are held in with at T9 Torx screw and then the sticky pads keep them fixed into place.

Batteries Availability?

Lofty:-E-mail to Scorpion alarms
Can you please tell me if you can retail the triple battery pack as installed in the scorpion siren unit fitted to the Mercedes 'A' Class. many cars now have problems with the alarms and require new batteries
. We are aware from our research that the battery is a Varta 6/V250H. Ni-MH 7.2 Volt 250mAh and could be easily replaced if available, your cooperation in this matter would be greatly appreciated .
A photo of the battery in question can be seen half way down the web page link attached. should you be able to assist a price would be appreciated.

Their answer was that they have never sold these battery packs. a follow up mail and answer, re the price of the siren unit complete was answered as follows :-
Yes you can buy direct it will cost 30.24 plus vat and carriage the part number is SIR002 this can be ordered from our sales department by phone
Many thanks


I mailed Rapid batteries to see if they can help Rapid have now mailed a reply, :-Hi,
Sorry we do not do that battery.
I've also spent a while looking at other suppliers for the battery but haven't come up with anything.
Thanks for placing a link to our site on your very informative website.
Many Thanks.
Rob Lazenby.
Most helpful Company.

Although the above company were unable to help with the scorpion alarm battery pack they have been most helpful and do sell batteries suitable for your remote key fobs, computer, and many other electrical items, their prices are the most competitive I have seen and invite you to take a look by link to their site using the icon above.

If you do purchase from them they have agreed to give my readers a further 5% off the listed prices, again I would please ask readers not to abuse this by passing on the code word.
Place your purchases in your shopping basket, when complete proceed to the check out, there you will see provision to enter a code word "If you have a Promotional Code please enter it in this field and click on the 'Apply' button at this point enter the word:- aclass,(Note this is in lower case)this will deduct 5% from from your total bill for goods only P&P cannot be discounted.

Refitting your new battery is the reversal of removal but you can guarantee the o-ring will be useless and therefore I would recommend a thin bead of silicone sealant between the two half's of the alarm casing when you put them back together.

do not forget to refit the wiring plugs to the circuit board!

The circuit board is attached to the siren by two short connectors, DO NOT attempt to remove these from the PCB or irreparable damage may be caused.

Bearing in mind the location of this unit which is exposed to damp and cold having resealed the body with silicone or if you have one a suitable sized 'O' Ring, make sure you also reseal the loom-cover(in which the wires are housed) which enters the siren unfortunatly the connector plug will prevent you using shrink tube.

Thank you Mozza, for your photographs and detail put into this section.

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