Replacing Alarm module Battery
 

Hi All


I decided to change battery on sounder module, which failed after I had disconnected my main battery for a long period of time while car was being wrapped in color change vinyl.


Car will lock and unlock with remote but alarm will not go off even if car is locked and I open the door. there is also alarm service required message in instrument cluster. Part from AM is about $ 200-300. If I am successful at replacing battery and it fixes the problem it will be about $ 25 but its not only $$, able to fix problems myself gives me satisfaction and sense of high.


If I fail at least it will help others either to avoid the project all together or avoid my mistakes.


I used only a thin flat head phillips screw driver, hammer, metal grinder, soldering gun , hack saw and volt meter.


please see pictures below.


So far I have been able to open up the inside plastic unit.
Battery is a Varta 6 V 140 mAh rechargeable Ni-MH battery. I think model Number is 5/V150HT


I am not able to find this particular battery online so far.
I did find on ebay similar specifics but no connecting pins, original battery had 5 pins which goes in to circuit board and its soldered to Circuit board

Ok
So I was able to remove the soldered battery
Now biggest problem is finding the exact same battery
Original battery is VARTA 5/V150HT WITH 5 pins (2 on positive side and 3 on negative side)
Not sure why need so many pins to go in circuit board.
Looks like 2 polices are feeding the same circuit drawing on circuit board.

I was able to find Varta V150 but it does not have 5 pins needed to solder it to circuit board.

Any ideas?

Well, the battery may be a heavier component on the Printed Circuit Board (PCB) than most other components, and someone decided that 5 connections to the PCB would be enough to hold it in place in an automotive application...unless there are multiple points that need the voltage applied?

Is it possible to remove the "stabs" from the old battery and solder them onto the new one? Just a thought...

Yup that's the last resort idea in my mind.
You might be right about heavy battery and 5 pins

The extra terminals could also be for battery temp, as that will help the charge circuit know how much current to run when recharging the battery

ok I was able to get the battery off the ebay
it came without any terminals, original has 5 termianls.
I took 2 copper wires and soldered it (my friend keith did it)
we only used 2 point, one for positive and one for negative.
I put every thing back together
used epoxy based clear 2 part epoxy to glue back 2 black plastic halves and it did glue back together as I had cut them evenly (if you cut in smooth straight line, its easier to glue it back together)
put the part back in metal housing and put back in the car today.
Just now tested alarm system and siren did go off. so success, total cost about 20-25 bucks and sense of achievement PRICELESS.
I will post remaining pictures later on. Don't have it with me at the moment.

Here are the pictures of new battery installed and tested at each contact showing 6.2 volts even if I used only 1 positive and one negative pin

Some more pics

Nice write up, this will help others.

awesome writie up indeed!

This may be an overly simplistic approach, but can't this module be found at one of the AM wrecker parts yards?

If module is not being in car or if battery is not being charged or if it's old you may end up facing same problem of dead battery.

Module is not that expensive o think 200/300$ range but it's the excitement and sense of accomplishment that's what makes it fun

Perhaps this can help. A rather in-depth substitution chart including specialized batteries:
http://dantona.com

did this fix clear the alarm service message also ?
great job, always happy to see write ups on how to's

Thank you and yes it did fix, both error messages went away but note that I had loose connection on passenger side wheel well harness plug so that was the reason for error message but battery was drained too, it showed only 3 volts. Now it's possible if I kept on driving the car it would have recharged by itself ? May be , but will never know