DMP XT system battery not charging?

[InterestedinAV]

Someone with background in security systems probably knows answer to this basic question ...

Two year old DMP XT hardwired system.

Battery warning went off - before troubleshooting, I pulled the battery and charged it for a few hours. System sensing occurred and it passed so no more warnings - for four days.

Then same battery trouble warning. Troubleshooting shows 17.2VAC out of the transformer (16.5VA transformer) at terminals 1 and 2, but only 13.02VDC (spec is around 13.8VDC) being applied to the battery at terminals 3 and 4 (by what I think is simply a rectifier with an AC passthrough for the transformer power to terminals 1 and 2).

DMP unwilling to discuss - keeps telling me to contact supplier - I understand, but like repairing simple things like this myself.

Is this common with rectifiers in this circumstance? Is the rectifier repairable or replaceable? Is it generally common with other manufacturer boxes?

 

[Deleted member 24354]

Welcome to AV Forums. This is predominantly a U.K. forum and although you are most welcome, you may get very limited responses on queries on systems that are only sold in North America. You maybe better trying a more US centric forum on something like this.

 

[InterestedinAV]

Copy - grasping at straws, Mate!

 

[Fabien]

Taking on board some of the facts...

You charged the battery, fault went away then came back after four days.

So something it loading the battery AND it is not being charged by the PSU

Where you DC measurements done with the battery in situ? As this will load the PSU and may give different values if measured without the battery connected.

You could swap out the battery (depending on cost) as a potential source of the problem. But as Mushii said you may get more insight with a US centric forum.

Dependant on how good you are with electronics, the electrolytic caps in the PSU will always be a weak point over time. HOWEVER, even if this is a US PSU, the voltages in question are still dangerous, therefore a new PSU maybe an option after speaking with the vendor

Fabien

 

[InterestedinAV]

OK - well, hmmmm ....

Interestingly, after charging the battery (removed from the system and with a 2 amp 12V charger, to 12.7 V) just prior to starting this thread, the battery trouble reset and was obviously sufficient for several days, then was activated, again.

Yesterday, I removed the battery, followed the same charging procedure, but the battery would not charge above about 11.2 V - left on trickle charger, again, today - and, 11.06V ...

Looks like bad battery, after all ...

 

[InterestedinAV]

While ordering a replacement battery, reading reviews of the various batteries, I noted the general consensus from so many that these batteries last about two years. Further, many noted that after replacing them at the two year point - they replaced the next one at the two year point :-(

 

[Fabien]

Suspect that is more to do with the electronic environment the battery is operating in than the battery itself (persistent loading of the battery / bad charging specifications from the PSU etc)
Fabien

 

[InterestedinAV]

Absolutely a contributor to the early demise of the batteries - one could even go down the rabbit hole that the security industry is helped by replacing batteries

 

[InterestedinAV]

All - so, ordered a 1280 8 Ah replacement battery - marking is MightMaxx - made in Vietnam. Most others were Chinese.

Checked out of box at 12.93VDC ... installed ... will wait a few days for the 0400 warning horn . Battery I had removed a few days ago was 10.95VDC after sitting in warm area.

Thanks for your help!