No power from working battery

[moredun]

My battery pack was 3 x 1.6V giving a total of 4.8 volts compared to your 7.2 volts. Is your MR2 facelift?

Keep us posted if it works for your plz, must be lots of 20+ year old rechargeable batteries coming to end of life.

[fawtytoo]

My battery pack was 3 x 1.6V giving a total of 4.8 volts compared to your 7.2 volts. Is your MR2 facelift?

Mine is PFL.

[Gaz mr-s]

My battery pack was 3 x 1.6V giving a total of 4.8 volts compared to your 7.2 volts. Is your MR2 facelift?

Keep us posted if it works for your plz, must be lots of 20+ year old rechargeable batteries coming to end of life.

Looking again at your pic, you had 6 cells in 3 pairs, - so probably 7.2v

[rusty0273]

Anyone know if you can simply remove the backup battery pack and rely on the 12v for the alarm siren or will this result in the 16 beeps or alternative nagging from the car? If you remove the siren unit entirely, that could impact insurance cover.

[Gaz mr-s]

Anyone know if you can simply remove the backup battery pack and rely on the 12v for the alarm siren or will this result in the 16 beeps or alternative nagging from the car? If you remove the siren unit entirely, that could impact insurance cover.

Read Post #24.

[rusty0273]

Read Post #24.

Hi. I've read the thread so understand what the purpose of the backup battery is. My question is whether it can be removed from the siren or will cause issues. moredun removed the whole siren so obviously would not hear any beeps indicating a fault.

[moredun]

Hi. I've read the thread so understand what the purpose of the backup battery is. My question is whether it can be removed from the siren or will cause issues. moredun removed the whole siren so obviously would not hear any beeps indicating a fault.

As it stands, although no audio  from the alarm, everything seems to work ok. Remember you still have the indicators for visual feedback ie locking and unlocking the car, deadlocks etc. There are no nagging buzzers or led's to indicate a fault with the alarm.

While the siren was off the car, I broke my leg and have been unable to replace the siren without the batteries and test it. Give it a couple of more weeks and I will try it then.

[rusty0273]

Thanks and wishing you a speedy recovery.

[rusty0273]

Different battery in mine ...



And that was a bit clumsy of me ...

My battery looks like this one. Did you find a replacement? Searching seems to come up with the alternative '3x2 cell' format rather than our 6x1 versions.

[Gaz mr-s]

Whatever the shape, it's 6 x 1.2v nicads.  If there is some extra space that will allow the pack to be slightly larger, 6 cells could be bought & soldered together with an adequate iron & thin insulated wire.

There might be packs ready-made for the likes of radio controlled products. Vehicle or transmitters perhaps.

But I'd be checking first if the charging cct works, otherwise there's no point.

[rusty0273]

Thanks. I can confirm that the alarm still works fine with the rechargable battery removed or disconnected (as long as you have main 12V battery supply obviously). It looks like a 2/3 AAA format and I've had a good look on the web with no luck finding a 6 x 2/3AAA 7.2V pack ready to go.

[Gaz mr-s]

More likely 'aa' size, although if I remember correctly they aren't named using same terms. 

[Gaz mr-s]

https://ebay.us/m/HbdHEl     Need to check dimensions.   - Size:84*48*18mm


Probably be ok.   Is the charging cct still ok?

[rusty0273]

I'm probably just going to run mine without the backup battery but for anyone else who's looking, the pack in my car which looks the same as fawtytoo's battery, is approx 60mm x 30mm x 10mm. 6 cells in a line. There is a tray in the sounder designed to fit this size quite precisely (the tray is visible, holding the battery pack in fawtytoo's photo).
Its a GP battery, P/N GP 28AAAM6BML.

Re, the charging cct - not my bag I'm afraid - don't even know what it is, how to identify it or test it.

I've just found these which are listed under an equivalent P/N and could be a direct fit but the connector looks slightly different (ex Hong Kong).

https://www.ebay.co.uk/itm/297991409847
https://www.ebay.co.uk/itm/286572430695

Maybe somebody can take a punt and feedback.

[rusty0273]

Bit more searching - this looks right, although no dimensions listed. UK seller.

https://www.ebay.co.uk/itm/163226209115

[Gaz mr-s]

Re, the charging cct - not my bag I'm afraid - don't even know what it is, how to identify it or test it.

Do you have a multi-meter?

[rusty0273]

Yep, I do.

[Gaz mr-s]

Yep, I do.

The battery has two wires.. same plug connections for battery operating the siren, or the car alternator charging the batteries. So put meter across the car plug terminals & (I assume zero volts). Now start the car. If still zero volts that'd suggest it's not working.  If you do see a voltage, post what it is please.

[rusty0273]

The battery has two wires.. same plug connections for battery operating the siren, or the car alternator charging the batteries. So put meter across the car plug terminals & (I assume zero volts). Now start the car. If still zero volts that'd suggest it's not working.  If you do see a voltage, post what it is please.

The sounder is reassembled and back on my car now I'm afraid (absent one battery).

[Gaz mr-s]

The sounder is reassembled and back on my car now I'm afraid (absent one battery).

Since you value it, do you know about moving it, for more space, but also making it much louder?