Ferrari Alarm Battery Modification

By Dick Maury

In reading on the forums about the battery failures in the alarm module, I decided to modify the system. I did read about remote mounting the battery pack and removing the batteries from the curcuit board and decided this was the best route. I had to piece it together as far as the proceedure to accomplish this. I decided to add a bit more with pictures to help anyone else trying this. The car is a 2004 Ferrari spider.

First step is to remove the left and rear panels in the front "trunk". These unscrew with a 4mm allen wrench. There is a dust/moisture shield behind the rear panel. Only a bit of the drivers side needs to be peeled back. If you tear it, you can tape it back when the job is done. Here is a picture of the module:

There are two 10mm nuts on either side, these need to be loosened, not removed as the module will slide off the brackets once loosened. Then pull off the wiring connector once loose. Now with the module on the bench, you will need to take it apart. Carefully using a knife as above, follow the seam around until the knife penetrates. Stop there so as not to damage the internals. Once through all the way around, you can separate it and you will see the curcuit board with batteries as below:

You will need to remove the batteries. I ended up snipping them so as to not heat up the circuit board so much. Once removed, solder in a red and black wire. Other colors can be used but this is pretty much universal in the car world for positive and negative. Note that there were two positive terminals and two negative terminals off of the original batteries. They are jumpered together on the circuit board so either hole will work fine for the new wires. Drill a convenient hole in the side of hte alarm housing to pass the wires through. Once through the hole, use some epoxy and glue the housings back together. Also apply a bit of epoxy to the wires to seal out moisture. Picture below shows the wires coming out of the housing.
The battery packs add up to 7.2 volts. There are a lot of ways to accomplish this. I chose to use two 3.6 volt Lithium Ion batteries as they seem to be the best at this point for holding and taking a charge. You can also use NiMH which is Nickel Metal Hidride or NiCd which are Nickel-Cadmium. The NiMHs do not have a charging memory. As in the picture below, I joined up two holders and jumpered the red and black wire on one end which gives me two batteries in series for 7.2 volts. Use enough wire so that the battery pack can be located conveniently. I attached it on top of the brake fluid reservoir with velcro so it would be easy to change out the batteries when the time comes.

Another option on a battery pack is a RC control pack with 7.2 volts. There is a red and black wire already coming out so just a matter of hooking it up. At this time, I could only find this in NiMH and it was rather large. The tape around the battery packs is to make sure no metal touches and shorts out the batteries.

After posting this article on the Ferrari Forum, I got a lot of positive feedback which I would like to include. The Lithium Ion batteries have a different charging design so might not be compatable with the original wiring and charging rate. Be your own judge on this.

Interstate Batteries has what looks like a standard 9 volt battery but is a NiMH 7.2 volt and attaches with a readily available snap on adaptor which would make it easier to change when needed. Click HERE for a link to the battery. As these are only 150 mah, you might want to get two and wire them in parallel to obtain the same amount of power reserve as the stock. Thanks to Rugby in Atlanta for this solution.

Another good idea is to obtain the original batteries but mount them external from the alarm module. Mounting them in a pill container would keep them from corroding if they went bad before replacement. These can be found on a simple EBAY search or HERE from Interstate Batteries.. Thanks to Steve in California (Mello) for this solution.