Cheap Trick of the Day: Low Voltage Cut-Off for ARB Fridge & Others

[GRM]

I don't know about you, but I have had many experiences where my ARB Fridge has killed the battery. I've done the dual battery route, isolated them, and tried to be diligent with turning the fridge off after trips. Still, I wanted a low voltage cutoff for my fridge.

A few years back, tried to make one: https://forum.ih8mud.com/electronic-toys/194667-how-do-i-make-relay-turn-off-11-volts.html only to find that its not worth the $100 savings over an Engel Battery Monitor. Engel Australia - Portable Fridge-Freezers

Then a few weeks ago I decided to do another search for a battery cut-off solution. Eureka! I found one from Seco-Larm. This one is for alarm systems, but I found it also works on fridges. And at ~$15 its priced for the job.

Once back in the shop, I found that it has an adjustable voltage on/off settings. They very from:

Clockwise: 10.6v on, 9.5v off
Counterclockwise: 11.5v on, 10.5v off

In the counter clockwise position its perfect from preventing deep discharge of my batteries. Plus the 7amp rating makes it perfect for an ARB fridge.

Hopefully this find will help someone else out needing deep-discharge protection from their ARB fridge.

Seco-Larm
Low-Voltage Battery Cut-Off
Part # ST-BD01Q
http://www.google.com/url?sa=t&rct=...obXKDg&usg=AFQjCNEVNcqSZHCiRTlqNbKljorR7aimbQ

 

[jonheld]

My ARB has 3 settings for the low battery cutoff and they work well. Has never been an issue for me, but your project certainly seems like a good idea.

 

[GRM]

My ARB has 3 settings for the low battery cutoff and they work well. Has never been an issue for me, but your project certainly seems like a good idea.

Do you have a newer ARB fridge? Because my 42q doesn't have that feature.

 

[jonheld]

Yes. I picked it up this past summer. It has 3 settings for the voltage cut off as explained in the owners manual. I don't know what they are off the top of my head, but the medium setting seems to be the best for me. The high is the most sensitive setting and that kept shutting down the compressor with plenty of voltage left to start. I never tried the low setting .

Found the manual:
Shut off voltages are
10.1 low
11.4 med
11.8 high

Restart voltages are
11.1 low
12.2 med
12.6 high

This is from the manual. I have not checked these numbers with a meter.