divad Posted June 14, 2011 Posted June 14, 2011 I had the usual problem of the bell going off when there is a power cut. I replaced the backup battery and checked the fuse. My supplier sold me a 12V 2.2AH battery saying it would be ok even though the original battery was a 2.8ah and the recommended was 7ah. The bell still goes off when the power fails and the battery is still giving out 12.6 volts. The system is an intellisense 800L So is the problem the battery? or is it the board? Or is it me? Help appreciated.
Mr Marco Posted June 14, 2011 Posted June 14, 2011 I had the usual problem of the bell going off when there is a power cut. I replaced the backup battery and checked the fuse. My supplier sold me a 12V 2.2AH battery saying it would be ok even though the original battery was a 2.8ah and the recommended was 7ah. The bell still goes off when the power fails and the battery is still giving out 12.6 volts. The system is an intellisense 800L So is the problem the battery? or is it the board? Or is it me? Help appreciated. Have you checked to see if the battery link is fitted in the SAB? Check between trigger and +ve terminals when in alarm. Have you got voltage? The trigger should 'go low' in alarm. You should be able to locate the problem to the panel or the SAB this way. Hope I'm not teaching you to suck eggs... Have you checked to see if the battery link is fitted in the SAB? Check between trigger and +ve terminals when in alarm. Have you got voltage? The trigger should 'go low' in alarm. You should be able to locate the problem to the panel or the SAB this way. Hope I'm not teaching you to suck eggs... Okay so I re read the original post... When you say 'goes off' do you mean the SAB sounds when you drop the power to the panel? Does the SAB sound when in alarm with the power on? Does the panel stay powered up running on the battery when you ditch the mains? If not this would point to the battery fuse having blown. "They put me in a box with my coat on! I know it doesn't sound much.."
divad Posted June 14, 2011 Author Posted June 14, 2011 Sorry not to be clear on this one. Don't worry about sucking eggs. I'm a novice. Assume I know nothing. 1 The SAB (self activating bell) sounds during a power cut and only when the power is cut or in an alarm. It hasn't as far as I know always done this. 2. With power on and in alarm the SAB sounds 3. With the power off and in an alarm I don't know if there is power to the panel there is certainly no power to the key pad. Thanks for helping
MrHappy Posted June 14, 2011 Posted June 14, 2011 remove the battery frpm the battery leads & measure the output ? Mr Veritas God
Mr Marco Posted June 14, 2011 Posted June 14, 2011 Im with Mr Happy on this. I would check the battery first then using a meter check for a charging voltage coming from the panel across the battery leads (while the batt is still disconnected). It deffo sounds battery related as the keypad should still stay lit even with just the battery and no mains. There is a good chance that when the old battery died it blew the battery fuse and if this isn't replaced the battery is effectively disconnected. Use a meter on Ohms scale to test the fuse (out of its holder!). "They put me in a box with my coat on! I know it doesn't sound much.."
divad Posted June 14, 2011 Author Posted June 14, 2011 The voltage from the battery is 12.6V I'll test the fuse again tonight.
Mr Marco Posted June 14, 2011 Posted June 14, 2011 Did you get a voltage across the battery leads (battery disconnected)? "They put me in a box with my coat on! I know it doesn't sound much.."
breff Posted June 14, 2011 Posted June 14, 2011 Battery fuse or damaged charging circuit, test voltage at battery leads with battery disconnected The opinions I express are mine and are usually correct! (Except when I'm wrong)(which I'm not)
Mr Marco Posted June 14, 2011 Posted June 14, 2011 Forgot to mention the Ah rating of batteries. Ah stands for Amperes Per Hour and its rating tells you, in an ideal world, how many Amps of current the battery can supply per hour. As a very rough calculation if for instance your system (panel + detection + sounders and anything else connected) is drawing 500mA (half an amp) from the supply, then a 7 Ah battery should run your system for 14 hours. This doesn't take into account any changes in current drawn by the system or drop in voltage supplied by the battery. I've seen a correction factor of 0.7 applied to take some of these variables into account and as such would return a standby time with a 7Ah battery of 9.8 hours (7Ah/500Mv) x 0.7 = 9.8 hours. These calculations are just a guide and there are other factors to take into account especially with a signaled system. this forum has a good resource for calculations here.. As with any rechargeable battery this rating will drop over time hence the requirement to test batteries as part of a service visit. Don't forget that a battery straight off the shelf will need to be fully charged by the panel before achieving its rating as it could have been sat in a box for months. So to recap, check for voltage across the battery leads (should read around 12v). If that voltage is okay you should be able to discount the battery fuse as being at fault. It could be the case that you have a faulty battery, its not unknown. "They put me in a box with my coat on! I know it doesn't sound much.."
Mr Marco Posted June 14, 2011 Posted June 14, 2011 Battery fuse or damaged charging circuit, test voltage at battery leads with battery disconnected As Breff says even if the battery fuse is okay there is a possibility that a component has failed in the battery charging circuit on the PCB. although repairable I would recommend replacing the PCB (unless you are hiding your electronic fault finding and PCB repair skills from us!) "They put me in a box with my coat on! I know it doesn't sound much.."
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