Fire Alarm Systems

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How do you test batteries connected to a fire panel if you only have a multimeter?
going from posts in the past... you look at the age of the battery.
Are you having a laugh!!!
Lick the terminals Biggrin
(23-10-2011 07:45 PM)ljarrald Wrote: [ -> ]going from posts in the past... you look at the age of the battery.

How's that 'testing'?
oh sorry. i thought he meant like, how do you know if they need replacing?
i need to learn to read :)
As far as i am aware you cannot get a true test reading from a multimeter. We use a battery load tester which gives a voltage,amplige & temperature reading. Had this argument with a spark before. He tested a battery with a multimeter and got a reading of 13.1v which he passed and assumed were strong enough to hold up the panel. 2days later power fault appeared on panel. less than 1amp running through each of a 12v 3.2amp battery. As far as i am aware you will near enough always get a reaing of around 12v from a multimeter. The only thing we use a multimeter for is to get the panel battery terminal charger voltage to record on paperwork. Would recommend a battery load tester everytime only cost about £100, but atleast you get an accurate reading of what the batteries are really up to. Hope this helps
The way to test the condition of any standby battery is to measure its voltage over a period of time whilst it is 'working quite hard'.

The way you make a battery 'work quite hard' is to apply a discharge load to it.

If you have no other test discharge 'load' you can almost certainly use the alarm load of the control panel as the 'test' discharge load. (if no-one minds you sounding the alarm!)

Therefore it is quite feasible to test the condition of the standby battery in a fire alarm panel with only a multimeter.

Fancy automatic testers can make your life easier, but an experienced fire alarm engineer who understands how a sealed lead acid battery performs, can easily ascertain it's condition to a fair degree of accuracy with just a discharge load and a multimeter.
I usually just drop the power, throw it into fire and stick a multi meter on it to be honest mate.

Ive had those fancy testers in the past and found them to be over rated really.
Agreed with above posts. testing with a multimeter simply gives the terminal voltage with no load applied. If the batteries are knackered you could still get a reading of around 12v (24 for the pair) but as soon as they are placed under any load (mains fail with alarms for example) you would find this voltage very quickly collapse!!

If no load tester is held and you cannot ring the bells, fail the mains and take a reading. At the end of your service (hopefully a good few hours lol) take another reading and if the voltage has dropped significantly, they'd be suspect.

Don't forget visual checks for date (less than 4yrs old), corrosion or build-up around terminals or any signs of distortion. Check charging voltage is not overcharging batteries too!
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