Running battery cable into truck bed for dual battery setup

[DiploStrat]

Never Used One ...

so I can't comment.

A proper camper power system is not that hard to set up and GM vehicles have better charging systems than most. I find that you always need more power than you have. That said, there is a bit of magic that sets in when you have:

-- 100Ah of usable battery, that is 200Ah of battery.

-- 200w of solar to charge that battery(s), that is about 10-15A available in good sun. This carries your 5A background load and puts another 5A into your batteries.

-- An intelligent relay to make sure that any charge is shared with all of your batteries.

-- A decent inverter/charger so that you have 110v AC AND a powerful shore charger to keep your batteries happy. (And that intelligent relay obviates the need for AMP-L-START or other band aids to keep your vehicle battery happy.)

I suspect that the cost/power of what I am recommending will be reasonable.

 

[jimi breeze]

I run a dual battery in my 2010 Silverado to power the camper and winch. I have used this set up extensively with no problems. Well I did run out of juice after a four day camp which is why I use the solar panels now.

under the hood parts: Painless Wiring solenoid, 550 CCA battery, tapped into the factory trailer wiring then spliced into the camper. 90watt solar panels.

in the cab parts: 400 watt converter, DC power plugs (1) ISO 4165 which powers the fridge inside the cab (1) cigar type, solenoid battery switch, USB power.

in the camper parts: 120v to 12v converter (to plug into AC when available, fuse panels, led lighting, Fantastic vent fan.

 

[Smoky]

DiploStrat...my alternator puts out 145 amps so would the Blue Sea ML-ACR Automatic Charging Relay with Manual Control be the unit I'd want? It's rated for alternators that put out up to 500 amps while the one you mentioned is rated for 65 amps. Or, is there a better option given my alternator?

 

[DiploStrat]

This is the unit that I recommend (and wish that I had on my truck): https://www.bluesea.com/products/7620/ML-ACR_Automatic_Charging_Relay_-_12V_DC_500A

At a 500A rating, it is a bit of overkill for most of us. I have a pair of 125A alternators and use a 200A rated relay. But for some reason, Blue Sea do not fit a manual override switch on their 120A model. In any case, the price difference is not that great.

If you're bored, you can use this to help size your cables. You want to keep the voltage drop to 0.5v if you can. http://www.calculator.net/voltage-drop-calculator.html?material=copper&wiresize=0.3224&voltage=14&phase=dc&noofconductor=1&distance=15&distanceunit=feet&amperes=100&x=38&y=6

 

[Smoky]

DiploStrat, using that Blue Sea unit, what would the proper wiring sequence be with a solar-supported, dual-battery system where the auxiliary battery is in the engine compartment and there's an inverter in the camper cap?

 

[Smoky]

Jimi...how do you connect your solar panels into your dual battery system so they charge your aux battery?

 

[IdaSHO]

For starters, I fail to see a fuse.

Beyond that, Id add covers to all positive terminals, as well as insulate (for abrasion resistance) the large conductors that are making contact with each other (to and from the relay)

 

[ajmaudio]

that would be over current protection device... aka fuse or breaker.. preferably within 18 inches of battery max... and before any other devices...... Other food for thought for the OP.... while I realize space in your bed is at a premium, do consider that engine bay heat doesn not help battery life, and any expensive deep cycle etc will live longer not in that environment. If you research temp vs battery life you will be shocked!

 

[DiploStrat]

DiploStrat, using that Blue Sea unit, what would the proper wiring sequence be with a solar-supported, dual-battery system where the auxiliary battery is in the engine compartment and there's an inverter in the camper cap?

Look here, plenty of diagrams: https://diplostrat.org/documents/

The physical location of each item is determined by space available, ease of wiring runs, heat, etc.

 

[Smoky]

DiploStrat...excellent resource...thanks.

In the paper entitled, "Dual Battery Slides," there's a diagram for a dual battery setup with intelligent relay and solar. In that diagram, lines extend from both sides of the relay to a midpoint on either side of the relay. What does that midpoint represent? Does it indicate that the cables from the relay connect directly to the positive pole of each battery...or does it represent a connection between the two cables on each side of the relay...or does it represent something else?
.
Forgive my ignorance...this stuff is all new to me.

 

[jimi breeze]

Good eye, but what you can't see are the fuses behind the black plastic cover (along the fender). Also this is an older pic, the solar panel wires are directly to the battery via a 6 awg quick disconnect (it's hanging out of the grill)

As Expo Nitpicker for this week, I am required to ask, Whats missing in this picture ??

Hint, Its initials are OCPD...

 

[DiploStrat]

I Could Have Been Clearer

DiploStrat...excellent resource...thanks.

In the paper entitled, "Dual Battery Slides," there's a diagram for a dual battery setup with intelligent relay and solar. In that diagram, lines extend from both sides of the relay to a midpoint on either side of the relay. What does that midpoint represent? Does it indicate that the cables from the relay connect directly to the positive pole of each battery...or does it represent a connection between the two cables on each side of the relay...or does it represent something else?
.
Forgive my ignorance...this stuff is all new to me.

Sorry. The diagram is "logical" not "physical." But I will change it.

For the moment, ignore how the manufacturer gets power from the alternator to the start battery - YOU want to run a cable from the positive terminal of your start battery to one side of your relay. And another cable from the other side of the relay to the positive terminal of your camper/house battery. Period.

Notes:

-- The cables should both be properly sized for the load. With a 200A+ alternator, I use a pair of AWG 1/0 cables which gives me about 100mm2 of copper.

-- The cables need to be properly fused at BOTH batteries. Remember, if that cable shorts, at any point, it is live from both ends. I use Blue Sea terminal post fuses because they are dead easy to install.

-- The camper/house battery will need a shunt on the negative side unless you use a SmartGuage. http://www.balmar.net/?page_id=15245 If you use a shunt, make sure that nothing bypasses it or your monitor will give screwy readings.

-- The camper/house battery needs to be grounded to the same point, usually a frame rail, as the starter battery and the cable from the negative terminal of the battery must be the same size as the cable to the positive terminal.

Does this help/make sense?

 

[IdaSHO]

Good eye, but what you can't see are the fuses behind the black plastic cover (along the fender). Also this is an older pic, the solar panel wires are directly to the battery via a 6 awg quick disconnect (it's hanging out of the grill)

The relay should be fused.

As in, an inline fuse or breaker between the battery and the relay.

 

[ericvs]

Smoky, for the cable running into the bed, I think your truck has a drain hole in the bed in the front corners. You could probably just run your wire up through that hole and put that therapy money into some cold bevies or something? My 2001 sierra had them, IIRC they were about 1/2"dia hole.

 

[jonyjoe101]

as far as battery placement, I have a kinetik khc2000 agm battery (102 ah). Its installed inside my astrovan in the back. Before that I had a 75 ah and a 145 ah agm batteries. Never had any problem with them in the 4 years I had agm batteries and I sleep in the back. You can always put a vent hole near where the battery is (i never had any reason to put one).
From my own experience its safe to put a agm inside a camper as long as it is properly tiedown so it dont move around. Thats the real hazard.