Had a power outage a few nights ago and my alarm bell outside starting going off (with its internal battery powering it). When I checked the panel, it was dead, so I suspected a failed battery. Cheched the battery this morning and it was pushing out just 3v, so I bought a new one, and replaced the blown battery fuse inside the box. Now when I simulate failed power, by switching off the mains breaker feeding the alarm, I am still getting the same issue - dead panel etc and alarm sounds outside etc. So it looks like the battery is not holding up the box. 

 

The battery I took out was a 2.1Ah 12v Yucel C20 - I bought a new 2.1Ah battery from Screwfix, and it ended up being exactly the same as the one I was replacing. Wondering if the 2.1Ah is the issue - I.e. too low, as the installer manual says max 7Ah (doesn't mention minimum though!)

 

Any ideas why the battery might not be holding up the panel in a power cut?

 

Thanks, Paul A

Blown battery fuse maybe?

Hi And welcome

 

If the battery was dead for some time, it would of most likely damaged the charging circuit

As Pete says, id say your pcb is blown

Thanks for the replies fellas. I had replaced the fuse as mentioned earlier, so I know its a good one in there. Since I wrote the OP above, the battery must have charged itself up a little as I just tried it again and the panel stayed lit when I dropped the mains power, so it looks like it was the battery being new and not fully charged yet which was the cause. I am wondering though whether I should have gone for a slightly higher Ah battery - the power was out for 3 hours the other night so wondering whether a 2.1Ah battery would hold up my system (6 PIRs) for that long. Any advice on whether I should exchange the battery for say the 7Ah one?

 

Thanks, Paul

Edited January 15, 201412 yr by Paul Atherton

Only way to br sure is to measure ur standby current usage

I went ahead and exchanged the battery for a 7Ah one. All working fine now! Just hope I can convince my neighbours to have their faulty batteries replaced to prevent more sleepless nights when we have power cuts ;o)

 

Thanks for your advice everyone. Much appreciated, Paul A