Ade Accenta G4 - Backup Battery Fault Mystery

[opacey]

Hi all.

I have a Honeywell Accenta Mini G4 Alarm panel with LCD keypad (8SP399A), 4x PIR sensors and one AG8 and one AG6 bell boxes. All is working fine until there is a mains power cut at which point the system behaves as if there is no power at all (ie, no backup battery in the panel, which in fact there is):

 - AG8 and AG6 sirens and strobes are triggered (they ring with an intermitting pause every couple of seconds)

 - LCD keypad display is on but not responsive to any buttons, LCD display gradually fades to blank over about a minute

 - Red power LED on the panel fades gradually until it is off

 

I suspected that the lead acid (AB21) battery was dead but removed it and using a multimeter found 13.5v across its terminals and after an hour on the desk it still showed 13.5v so I assume it is fully charged and able to hold that charge for at least an hour.

 

I also found 13.5v across the terminals that the battery wires connect to on the main panel (with battery removed).

 

Clearly the panel is able to charge the battery, and it would seem the battery is functioning well (4 years old installation) but somehow that backup power isn't getting to the rest of the logic board. Could this be a fuse problem? I called Honeywell Support but they weren't very much help in further diagnosis. It seems supplier only sell the whole package (panel + keypad) and I'm on a really tight budget so only want to replace the minimum of parts.

 

If anyone can help me further diagnose this behaviour I would be delighted!

 

[sixwheeledbeast]

Faulty battery, system overloaded or possibly faulty panel?

 

You can't test a battery or charging circuit without a load on it.

[Hillbilly]

First of all check the glass fuse with a multimeter. If ok then get a new battery as its the load as in amp hrs that the battery has.

If the battery has not been changed in a long time there could be a fault on the board.

[antinode]

I'd put money on it being the battery. Output voltage is only one consideration, it's when the battery is placed under load that it will prove itself. Try checking the battery voltage with it connected to the panel and the mains disconnected. If it's still reading above 12 volts, it's the panel although I'm fairly sure after 4 years, the battery has had it and the voltage will plummet.

[al-yeti]

Shake battery can you here it rattling lol

[WDT]

Shake battery can you here it rattling lol

 

lol

[Flossyrockstar]

Remove the mains supply and put a meter across the battery terminals that'll tell you if it's cattled!

Edited December 19, 2015 by Flossyrockstar

[norman]

Cut the mains

you may want to rephrase that bearing in mind were in diy

[Flossyrockstar]

you may want to rephrase that bearing in mind were in diy

Good shout Norman, I didn't realise!

[PeterJames]

This is why battery manufacturers recomend they are replaced every 4 years. DIY are not going to go to the expense of buying an ACT gold meter and load test the battery every year.