Think I can use these to replace my alarm siren battery?

[Luxus Panzer]

here is a link to the job itself...

http://www.audi-sport.net/xf/threads...tteries.90361/


I found these batteries at a local surplus store, could I use 2 of them wired in parallel ??

[fR3ZNO]

Voltage is good and matches spec.

The mAh is quite larger than the OEM amount mentioned in that thread, but that just means your batteries will last longer and hopefully you'll never have to replace them again!

[Andy_FL]

Did you already crack open the box? If not, better make sure it doesn't look like this before you start planning for just a battery replacement:

[Luxus Panzer]

yup

[naconi]

I am pretty sure you need 7.2 volts so those new batteries have to go in series not parallel.

Why are you replacing your original batteries? They aren't leaking. They are also different from the ones I have seen pictures of leaking, is that the newer model?

[Luxus Panzer]

I am pretty sure you need 7.2 volts so those new batteries have to go in series not parallel.

Why are you replacing your original batteries? They aren't leaking. They are also different from the ones I have seen pictures of leaking, is that the newer model?

My alarm works, however with it installed I keep having my interior lights fuse blow.

Gonna replace the batts as troubleshooting

[DPDISXR4Ti]

They are also different from the ones I have seen pictures of leaking, is that the newer model?

Yes, that's the newer one. I just got one at the junkyard and was wondering how the batteries were configured, so good timing.

I was thinking about proactively replacing the batteries even though it works now. I figure they're 10+ years old - if I replace them now, it will probably be the last time.

Anyone know of a source?

[diagnosticator]

I used a 7.2 volt Ni Mh battery with a pair of leads attached, soldered to the circuit board +/- and mounted the pack on the outside of the case. The circuit board needs a jumper from the negative to the positive to connect the 7.2 volt battery leads with only 2 connections.

[Luxus Panzer]

I used a 7.2 volt Ni Mh battery with a pair of leads attached, soldered to the circuit board +/- and mounted the pack on the outside of the case. The circuit board needs a jumper from the negative to the positive to connect the 7.2 volt battery leads with only 2 connections.

Do you have any pics of this jumpering ? If not I will get some pics of my PCB when I take the Batts off.

[naconi]

Yes, that's the newer one. I just got one at the junkyard and was wondering how the batteries were configured, so good timing.

I was thinking about proactively replacing the batteries even though it works now. I figure they're 10+ years old - if I replace them now, it will probably be the last time.

Anyone know of a source?

Mine is 12 years old this year so I was thinking about preventative maintenance. Either replace or do the external. This looks like the correct replacement

http://www.aliexpress.com/item/Free-...408.3.2.oeUIT6

[DPDISXR4Ti]

Mine is 12 years old this year so I was thinking about preventative maintenance. Either replace or do the external. This looks like the correct replacement

http://www.aliexpress.com/item/Free-...408.3.2.oeUIT6

Yep, good find.

[Luxus Panzer]

Kinda high $$ for that battery

I am going to go with these cell phone batteries as they are in sale for 1.99 each

[walky_talky20]

280mah vs 1400mah. Your alarm will run for, like...days.

[Luxus Panzer]

So I grabbed 2 of these battery's today.

Here is what they look like on the inside..




Wired them up in series to X2 the voltage to the required 7.2v



then added my jumper wires to take to the PCB on the siren..



Bit of hot glue to keep everything in place and prevent shorts...



This is where I need some help from someone who has been there and done that....

What 2 points do I jumper and where do I connect my + and - from the battery's?

In the following 2 pictures the dental pic is positioned over the same point so you can keep your orientation (pic of each side of the PCB)

[Luxus Panzer]

So I had a look at the PCB and probed with a DMM for connectivity.

I decided to use these 2 spots for my + and - I hooked it up and it worked. I unhooked it and will put itback in today when I am doing some work outside so I can monitor it for charge and ensure it does not light on fire.




Once I took the wrapper of my stock batteries...I most definitely have some leakage.

[Luxus Panzer]

I am not sure if the batts are charging in this configuration.

I just left it plugged in for 1/2 hour. The batts had a combined voltage of 3.8v (half dead from being in the package on shelf for years) and after 1/2 hour the voltage at the batts has not gone up.

[Luxus Panzer]

I used a 7.2 volt Ni Mh battery with a pair of leads attached, soldered to the circuit board +/- and mounted the pack on the outside of the case. The circuit board needs a jumper from the negative to the positive to connect the 7.2 volt battery leads with only 2 connections.

Please tell me you have pics of the jumper and where you connected the + and -

[Luxus Panzer]

update.... it was not working.

I swapped my - and + connection from my batt pack to these 2 locations (only need to use one of each pair as they are connected in the PCB).... so far so good.

[diagnosticator]

There must be a connection between the two 3.6 volt batteries to have 7,2 volts with the two batteries in series. Depending on where the external battery leads are connected to the circuit board, the connection trace in the PCB will do this.Otherwise a jumper needs to be added between the two batteries between + and - on only one end of each original battery location to provide the series connection and 3.6 volts to the circuit board components and battery charger circuit.

[Luxus Panzer]

long term testing will tell.... but I have no jumpers on my PCB and jumper-ed the battery themselves (see pics above)

I am off to Cuba for a week so I will do some testing when I get back. So far all is well.

[diagnosticator]

long term testing will tell.... but I have no jumpers on my PCB and jumper-ed the battery themselves (see pics above)

I am off to Cuba for a week so I will do some testing when I get back. So far all is well.

I agree. Seems that you are hooked up to the right connections on the PCB.