Fridge power?

[JPK]

The AGM battery I'm looking at is an Interstate unit that is very small and has screw on terminals so you can likely easily insulate them to prevent accidental discharges. Securing it is the thing I need to focus on now. I also thought about getting a low voltage cutoff switch. How much are they? Any recommendations on a reliable one?

To run a fridge you would want a deep cycle battery, typically in the sizes we're discussing, a marine or maybe RV battery.

I have been successfully using a cheap KollTron 12v extension cord/cut off switch between my Engel and a cigarette plug for about 15 mos. My one and only battery is a Grp 31 Blue Top Optima (Yellow Tops are also deep cycle, but in my area, near Annapolis, MD on the Chesapeake Bay, it's easier to find the (slightly more expensive) Blue Tops. Sears Die Hard Platinum marine batteries are TOP quality, reportedly made by Odyssey, which sells deep cycle and starting batterries under their own brand too. Also, while adapters from typical automotove lead post terminal to screw terminals are easy to find, the marine batteries almost all have two sets of terminals, the typical automotive posts and also screw terminals.

Here's a link to the cheap ($27) and effective KoolTron extension cord/cut off switch - which cuts of fridge power at 11v, ok for a deep cycle but too low for a starting battery, imo. http://www.roadtrucker.com/koolatron/koolatron-12-volt-cooler-accessories.htm

JPK

 

[jeep-N-montero]

One thing I've seen done and also plan to do is to mount a small 12v deep cycle AGM battery in the back. That way I don't run down the starting battery (even though that's also a deep cycle) overnight should something go wrong with my ARB fridge. I saw this setup in Grasscat's rig and it was pretty sweet. When wheeling he simply plugged the small battery back into his rear cigarette lighter outlet to recharge it.:ylsmoke:

I know the thread is a few months old, but do you know what gauge wiring he used from the front to the rear outlet, and from the outlet to the battery?

 

[trevan]

I have recently purchased an ARB fridge and having been looking through the forum for info on how to wire them in.

One of the earlier posts talks about a small battery used to power the fridge when the engine is off and the use of the aux outlet when the vehicle is operating.

I have an interim setup that is similar.

My question is could you connect the battery to the aux outlet and then the fridge to the battery. If the Aux outlet turns off with the ignition key then the fridge maintains power from the battery and in turn when the engine is running the battery would receive a charge.

Seems so simple that it must break some wiring principles!

Jim

 

[Jay H]

I have recently purchased an ARB fridge and having been looking through the forum for info on how to wire them in.

One of the earlier posts talks about a small battery used to power the fridge when the engine is off and the use of the aux outlet when the vehicle is operating.

I have an interim setup that is similar.

My question is could you connect the battery to the aux outlet and then the fridge to the battery. If the Aux outlet turns off with the ignition key then the fridge maintains power from the battery and in turn when the engine is running the battery would receive a charge.

Seems so simple that it must break some wiring principles!

Jim

It might work but there are quite a few potential problems with this.

1. You need fuses ideally one between the aux and second battery and also one between the fridge and second battery. Think vehicle fire.........

2. In my 2004 toyota the aux is regulated to 12.6 volts meaning a battery connected would never fully charge - this problem is huge and would kill a battery in short order.

3. Does your vehicle disconnect the aux socket while starting because if not current could flow from the second battery to the main battery while starting and it could be enough current to blow the fuse. And dont let any one tell you a simple diode will fix this. It will, but it it will also drop voltage and use a good bit more power. The voltage drop of a cheap diode will probably even be enough to cause low voltage cut out problems. In my toyota the 12 sockets and the stereo are disconnected while starting which is good for not killing sensitive electronics by feeding them low voltages.

4. Your fridge will run a little AGM battery flat pretty quick when sitting in the sun so a low voltage disconnect to protect the battery is a good idea. Most of these cut out circuits do not kick in soon enough. An average AGM battery will cycle half as many times before dying if run to below 50% capacity.

5. When the engine is running the vehicle would have to power the fridge and provide a charge, this could be quite a few amps depending on the size of the second battery.

 

[trevan]

Thanks for the great response! I thought it was too good to be true.

Two quick q's.

1) If I run a dedicated line to the fridge from the main battery do you think 10 gauge is good for a max run of 15'?

2) Is there a practical way of wiring up the remote battery in the rear of the truck so it can obtain a charge through the main battery or the Alternator? I have read a lot on this and there does not appear to be a clear answer. The typical solution appears to be two batteries under the hood but I have no room. Instead I have a large AGM battery for the truck and the winch. May not be a huge issue if I connect to the main battery as I can easily last 4 days on it and still get started. I have a low voltage cutout. In most cases I would only be traveling on the main and then switch over to my remote AGM battery which has a 100ah rating.

I see you are into cycling! After too many years in the sales rat race I took on a role in a not for profit cycling organization on the sport side. Early on I worked on bring IMBA into Canada. We are heading off in a week to act as Trail Host's at a Mountain Bike trail system in one of our provincial parks.

Jim

 

[Jay H]

Thanks for the great response! I thought it was too good to be true.

Two quick q's.

1) If I run a dedicated line to the fridge from the main battery do you think 10 gauge is good for a max run of 15'?

2) Is there a practical way of wiring up the remote battery in the rear of the truck so it can obtain a charge through the main battery or the Alternator? I have read a lot on this and there does not appear to be a clear answer. The typical solution appears to be two batteries under the hood but I have no room. Instead I have a large AGM battery for the truck and the winch. May not be a huge issue if I connect to the main battery as I can easily last 4 days on it and still get started. I have a low voltage cutout. In most cases I would only be traveling on the main and then switch over to my remote AGM battery which has a 100ah rating.

I see you are into cycling! After too many years in the sales rat race I took on a role in a not for profit cycling organization on the sport side. Early on I worked on bring IMBA into Canada. We are heading off in a week to act as Trail Host's at a Mountain Bike trail system in one of our provincial parks.

Jim

10 would be ok for powering the fridge but 8 would be better. For a remote battery 4 or even 2 would probably be more like it.

You could just put a fuse up by the battery and run 4awg back to the back and leave a pig tail hanging out with a large anderson power pole connector. Then put the AGM in a plastic battery box and have a dual battery kit in the battery box with it. This would give you a removable second battery. Kind of a DIY version of the expensive national luna power pack system. This would be an ideal set up. There are a lot of dual battery kits out there some are very fancy and some are just solenoids. There is a ton of info on here about the various dual battery systems. Using two batteries and never running them below 50% is far better than using one and running it down to 20%. In fact they should last twice as long. It should not be any different than wiring it up like a second battery under the hood, just a longer wire run.

I enjoyed riding in Canada a lot! The 7 summits trail in Rossland was amazing, one of the best rides I have ever had. I hope to ride more in Canada some day. Riding and trail building are two of my favorite things. My fiance and I interviewed to be the next IMBA trail care crew in the US but didnt even make it to the second interview. I am still on the look out for payed work trail building.

 

[pods8]

Cool, my ARB requires a 45 amp fuse.

(Edit just realized this is a relatively old post I replied to).
??? That sounds ridiculously high, is this one of the newer ones or an old one? The new one says use a 15amp fused circuit but there is also an 8amp fuse in the cig plug. Personally I never liked the cig plug power connection, it would wiggle and make/break the circuit, so I cut off my cig plug and replaced with anderson powerpoles, I plug that into a wiring with an inline 7amp fuse and it runs great. I put some powerpoles on the cig plug as well so I can put it back on easily if I need to for some reason.

 

[Jay H]

Anderson power pole connectors are great, other good connectors are XT60 and T-type (deans). I get mine from http://www.hobbyking.com/hobbyking/store/__377__58__Hardware_accessories_-Wires_Plugs.html
Hobbyking is also a good source of heat shrink and high quality silicone wire.

 

[pods8]

Here's a link to the cheap ($27) and effective KoolTron extension cord/cut off switch - which cuts of fridge power at 11v, ok for a deep cycle but too low for a starting battery, imo. http://www.roadtrucker.com/koolatron/koolatron-12-volt-cooler-accessories.htm

Also an old post to reply to but 11V is damagingly low* for a deep cycle too assuming you want decent longevity out of it.

*Under no load 11V is basically completely depleted, the caveat being no load. The fridge running will temporarily pull down the voltage some thus if under load it tripped at 11V then it really wouldn't have pulled it down that far but I'm "guessing" you'll have drawn the battery down into the mid 11s by then which is still a DEEP discharge.