Battery backup on M1Gold giving trouble

[TriLife]

Greetings,

The long power outages in California have exposed an interesting problem with the battery backup on the M1 Gold.

I have two 18Ah batteries as a backup for the alarm panel. One attached to the M1 Gold Panel the other charged by a supervised charger board to power accessories. These accessories include the cable modem/router (Netgear C6900), which is supplied by the same 12V.

Three times in a row now, after the multi-day outages, the modem resets itself to factory, thereby cutting off communication (no ddns, no ports for M1 Gold Access, No wifi for Nest).

I noticed that after a day or so without power, after the batteries reach low level and are turned off by the supervisors, the modem periodically had it's lights flare up, as if it was trying to start up. Just a few seconds at a time, maybe every half hour. I'm guessing the supervisors detect an increasing voltage (room temperature variations?) and try to turn the battery back on. Of course the load brings the voltage right back below threshold and it gets turned off again. I surmise that this power oscillation resets the modem to factory settings.

I have since made a backup copy of the router settings, so I don't have to reconfigure it from scratch every time, but I have to be on site to restore it. I live 9hrs flight time away from this site.

The M1 Gold can turn on the power to the PC, so as to remote in via TeamViewer but since I cannot reach it remotely, that doesn't do me any good. Current solution is to ask a neighbor to turn on the PC...

Any ideas on how to prevent this factory reset?

Cheers.

 

[RAL]

It's common for a SLA battery's voltage to drop under load, and then when the load is removed, the battery recovers and the voltage increases to some degree.  It sounds like that's what is causing the oscillation you are seeing.   The cut-in voltage is right at the level that the battery recovers to.
 
What are you using for the charger and low battery cut-off on the aux battery?  A low battery cutoff should disconnect the battery when it gets low and then it should not reconnect until AC power is restored and the battery is recharged.
 
I use some Altronix Low Power Disconnect (LPD) modules and they work very well.

 

[TriLife]

Thanks RAL,

I use the ELK P1215CB Module to charge and monitor the battery.

Cheers.

 

[tmbrown97]

I would agree that a low voltage cutoff seems to be necessary; and given how CA has been lately, maybe adding in a solar panel to keep that battery charged!

 

[TriLife]

Believe me, solar panels have been on my mind for a long time. Unfortunately, this cabin is on Donner Summit, the area of the contiguous US with the highest snowfall. Solar panels have a zero chance of survived mg even an average winter, let alone the 1,000" snowfall we got last year...

 

[RAL]

Thanks RAL,

I use the ELK P1215CB Module to charge and monitor the battery.

Cheers.

 
I haven't used the P1215CB, so I'm not completely familiar with it.  Looking at a photo of it, there doesn't seem to be a relay on the board, which would be the straightforward way to lock out the battery and keep it from reconnecting if the battery voltage recovers, but the AC is still out.
 
You could add one of the Altronix LPDs to what you have, and I think that should cure your problem.  The relay on the LPD will add a slight current draw to things, but with an 18Ah battery, I doubt you'll notice much difference.

 

[TriLife]

Good thinking. I will work on that circuitry over the winter. All signs are that this might be the last PGE outage we will see this season. I should be able to replace the relay with a MOSFET, reducing the current draw to zero...