Hoping for a simple dual battery set up

[deliBK]

Hi All... Sure could use some help. Just bought a 2000 L400 Spacegear Chamonix, 3L V6. Trying to figure out a simple way to run a fridge (thinking the ARB 63), occasional laptop, and a heated blanket (the wife sleeps insanely cold... I'm talkin frigid). I was hoping to get a deep cycle batt and somehow have it wired to charge off the main batt (alternator?), while driving. Not much room under the hood, so wondering what other options are available. Clearly I don't know much about this stuff. What I believe I've learned is that I need an isolator (100A?). I'm aware that there are specific Dual Batt Systems available to do just that, but in an effort to keep cost down, I'm wondering if there is a simpler, less costly method. Any help would be greatly appreciated. By the way, I visited an RV shop today. Terrible service, completely unhelpful and mostly a waste of time. The guy there suggested that running a fridge off such a system would drain it in an hour or 2. Can that really be right? Love to hear some thoughts. Big thanks!

[Feds]

The rv shop may have been rude, but they weren't wrong. My 12v cooler will drain the battery even when the trailer is plugged in and charging it.

If you are serious about remote camping, you should look into propane fridges and heaters. If you are mostly looking at camping at serviced sites, you'll be way better off fitting an rv-style converter, which you could then run with a generator when you're back country.

[lrp374]

What your looking @ is possible but first you have to determine the amount of real load. The ARB fridges are very efficient so could last a day or 2 with no charge IF you have a large enough battery. The electric blanket will be the tricky part if you really need it. You'll need to use an AGM type battery so you can mount it anywhere. Nothing is simple anymore!

[deliBK]

Thanks Feds and Irp.
Would the Odyssey 34-PC1500T be large enough?
Can/should an AGM batt like this be mounted inside without venting externally?
Is it possible (advisable?) to wire a 12V charger to the auxiliary power terminal of the trailer wiring outlet on the van? If so, any advise on how to do so? Presumably a charger would have a pos and neg terminal, but the aux pole has only one terminal. Any help is much appreciated.
Thanks again.

[lrp374]

I think if you search Engel on the site it will give you lots of info to decide what to do. Look especially @ info by Jessef as he did lots of good research. I think the unit you are looking @ could last 2 days on the Odyssey battery if it is not set on freezer! The battery can be inside just make sure it is secure and the + is no where near metal. I'm sure after the search review you'll even have more questions.

[Growlerbearnz]

For simplicity, I'd recommend a Voltage Sensitive Relay rather than an isolator switch. You simply connect your two batteries together- negative to negative directly, and positive to positive through the VSR. When one battery is above 14V the VSR connects them together (like when the engine is running, or if you're using a solar panel), and when the batteries drop below 12V the VSR separates them. Connect your fridge to the secondary battery and you can drain it as flat as you like, safe in the knowledge that your main battery is isolated and ready to start the vehicle.

Voltage Sensitive Relays are a bit expensive if you buy them from RV companies, but boatbuilders have been using them for years. Here's the one I have in my Delica: http://www.amazon.com/BEP-Marine-710-14 ... B00B27G1YE

[lrp374]

Growlerbearnz you have a great ( simple ) solution for everything!!

[deliBK]

For simplicity, I'd recommend a Voltage Sensitive Relay rather than an isolator switch. You simply connect your two batteries together- negative to negative directly, and positive to positive through the VSR. When one battery is above 14V the VSR connects them together (like when the engine is running, or if you're using a solar panel), and when the batteries drop below 12V the VSR separates them. Connect your fridge to the secondary battery and you can drain it as flat as you like, safe in the knowledge that your main battery is isolated and ready to start the vehicle.

Voltage Sensitive Relays are a bit expensive if you buy them from RV companies, but boatbuilders have been using them for years. Here's the one I have in my Delica: http://www.amazon.com/BEP-Marine-710-14 ... B00B27G1YE

Awesome. That's exactly what I'm looking for. Thanks a tonne!

[stever1000]

https://www.bluesea.com/products/7650/A ... Kit_-_120A

Similar idea to BEP marine but also includes the switch so you can combine both batteries. The blue sea kit is very popular with the VW camper crowd for adding a recreational battery

[deliBK]

https://www.bluesea.com/products/7650/A ... Kit_-_120A

Similar idea to BEP marine but also includes the switch so you can combine both batteries. The blue sea kit is very popular with the VW camper crowd for adding a recreational battery

Thanks Stever. I'm unclear on the difference. Would you mind elaborating?

[deliBK]

For simplicity, I'd recommend a Voltage Sensitive Relay rather than an isolator switch. You simply connect your two batteries together- negative to negative directly, and positive to positive through the VSR. When one battery is above 14V the VSR connects them together (like when the engine is running, or if you're using a solar panel), and when the batteries drop below 12V the VSR separates them. Connect your fridge to the secondary battery and you can drain it as flat as you like, safe in the knowledge that your main battery is isolated and ready to start the vehicle.

Voltage Sensitive Relays are a bit expensive if you buy them from RV companies, but boatbuilders have been using them for years. Here's the one I have in my Delica: http://www.amazon.com/BEP-Marine-710-14 ... B00B27G1YE

Just thinking about this... would it not be wise to connect the negative of the 2nd battery to ground, rather than to the Starter batt?

[stever1000]

Here is another member's photos with the blue sea system I posted: http://www.delica.ca/forum/viewtopic.ph ... ea#p127042

Both operate on the same principle: combine the batteries for charging above ~14V, and separate batteries when the main battery drops below ~12/13 volts. The blue sea kit includes a battery isolator as well, so you can choose between having battery 1 on, battery 2 on, both off, both on. Extra feature which you may or may not need.

[deliBK]

Here is another member's photos with the blue sea system I posted: http://www.delica.ca/forum/viewtopic.ph ... ea#p127042

Both operate on the same principle: combine the batteries for charging above ~14V, and separate batteries when the main battery drops below ~12/13 volts. The blue sea kit includes a battery isolator as well, so you can choose between having battery 1 on, battery 2 on, both off, both on. Extra feature which you may or may not need.

Got 'er. Thanks a tonne.

[calcos]

Keep us posted on what you end up doing...I'm thinking of doing the same thing at some point in the future. Good info all!

[deliBK]

Keep us posted on what you end up doing...I'm thinking of doing the same thing at some point in the future. Good info all!

Sure...
I spoke with quite a few different folks and read tonnes of stuff on line. Finally made decisions. We don't have availability to a marine shop so I've ordered stuff from Amazon.Ca as well as The Gear Shop in Calgary (great service and willing to "work" on pricing).
I've attached screen shots of the VSR, Inverter, an "emergency" batt booster (huge sale), volt meter, 20A dual bank smart charger (on sale), James Baroud roof top tent and the ARB 63 qt fridge.
Will update with photos once everything is installed.

Last thing I need to sort out is how/where to mount my Aux battery. Since we're sleeping on the roof, we've got lots of space for the fridge etc in the back. I'd like to just have the battery back there but still trying to figure out how significant off gasing may be. Seems to me that it's not a concern with an AGM battery. Any ideas or suggestions would be appreciated.
Thanks all!