Replacing an alarm battery with an "AGM" deep cycle battery

ld13

Honorary Master
Joined
Oct 28, 2005
Messages
12,371
So the alarm battery decided to go *pop*. Would an "AGM" deep cycle battery work. What is so different about it?
 

Everyones-a-Wally

Honorary Master
Joined
Jul 18, 2008
Messages
51,564
I cant answer your question but the considerations are charge current and time and Intelligence on the charging circuit. Different battery technologies have different requirements.
 

ld13

Honorary Master
Joined
Oct 28, 2005
Messages
12,371
I cant answer your question but the considerations are charge current and time and Intelligence on the charging circuit. Different battery technologies have different requirements.

That much I assumed as well. But with these alarm units I only know that it has a battery port on the board, and that is that. No info is obviously shown on the board about the charge current and how intelligently it goes about charging or protecting the battery.

Assumption 1: All alarm panels use stock standard SLA batteries.

A bit of googling tells me that SLA has typical absorption voltage range (charge rate?):
14.2 to 14.7 volts; typical float voltage range 13.1 to 13.4 volts, whereas AGM,
14.2 to 14.5 volts; typical float voltage range 13.2 to 13.5 volts.

Assumption 2: The panel will assume SLA and "charge" (might be using the wrong term here) the AGM between 14.2 to 14.7 volts and keep it floating at around 13.4 volts max.

So the charging rate is at the maximum, only 0.2 volts too high, but the float range seems ok? I do not see anything adverse happening here?
 

Gaz{M}

Executive Member
Joined
Feb 9, 2005
Messages
6,443
When my 7ah goes bust, I intend to put at least a 9Ah in there. AGM is still Lead Acid chemistry and I seriously doubt that the alarm circuit charges at high current or discharges at high current. You should be fine.
 

riscbroker

Expert Member
Joined
Sep 29, 2006
Messages
2,100
The voltage ranges you've quoted are also linked to temperature. The numbers are so close I wouldn't be concerned.
 

ld13

Honorary Master
Joined
Oct 28, 2005
Messages
12,371
Thank you for your feedback guys! Much appreciated.
 

thehuman

Expert Member
Joined
Nov 2, 2004
Messages
3,592
The alarms charger could maybe not keep up , could add a small smart charger to your bigger battery.
 
Top