Running battery cable into truck bed for dual battery setup

[Smoky]

I’m looking to convert my 2007 Silverado Classic into a retirement road trip vehicle. My plan is to install a dual battery system under the hood and run power under the cab and into the bed. Then, I’d like to install a power converter in the bed and run everything off of it – LED lights, vent van, table lamp, charging for phone and laptop, etc. I’d appreciate any ideas, photographs, videos, etc. about how to best get the battery cables into the bed. I assume drilling is required so am interested in best locations, as well as methods to ensure the holes I drill don’t rust and are water-tight. I know that some folks place their deep cell battery in the bed rather than the engine compartment but I really want to avoid battery off-gassing in my living space. Thanks, in advance, for your help.

By the way, I only recently discovered this site and am uber-impressed by all the knowledge and ingenuity shown by people here…very impressive!

 

[M35A2]

Just the basics that you are already aware of. Touch up the raw edges on the holes with a suitable paint. Use good quality grommets that fit the cables. Locate in an area where you can inspect and maintain as needed.

The first hole you drill in your nice sheet metal - that one is the emotional hurdle. But as you suspect, it's not a big deal.

 

[DiploStrat]

Free Advice is ...

worth what you pay for it.

Any battery(s) worth using for camping, say 200Ah, 100Ah usable, is unlikely to fit under the hood of a Silverado. Consider AGM batteries in the bed. The wiring isn't that hard as you can run it along the frame rails.

Do your homework FIRST (measure twice/cut once).

-- What is your load? Probably more than you think if you want a cooler or refrigerator. Heat is even more.

-- How long do you need it without recharging? Two days? A Week?

-- How are you going to recharge when you need to? Alternators are great for bulk charge but it is nearly impossible to assure a full charge without solar or shore.

You may find the reference materials on my website useful. I have scars ... :Wow1:

Good luck!

 

[Smoky]

DiploStrat

I've installed a second battery tray under the hood, measured the height from the tray base to the point where the hood closes, and identified a battery that will clear (Vmax MR107-85 Deep Cycle Battery). This battery doesn't have the reserve power you suggest but should be about right for my application, which would include mostly 3-5 day trips with an annual week-long trip. I'll need power to regularly operate and charge my laptop, charge my iPhone, occasionally run a vent fan, and power LED lights in the truck cap. I don't yet have a fridge/freezer but anticipate getting one. That's about it. I've explored the in-cap AGI battery approach and read that even such sealed batteries give off toxic gases so I'm not excited about doing that...but am open to information to the contrary I may not have seen.

 

[Smoky]

M35A2...yeah, I don't relish the idea of drilling through the bed but there really is no other way to do a clean install. Thanks for the advice.

 

[DiploStrat]

Do Your Maths

DiploStrat

I've installed a second battery tray under the hood, measured the height from the tray base to the point where the hood closes, and identified a battery that will clear (Vmax MR107-85 Deep Cycle Battery). This battery doesn't have the reserve power you suggest but should be about right for my application, which would include mostly 3-5 day trips with an annual week-long trip. I'll need power to regularly operate and charge my laptop, charge my iPhone, occasionally run a vent fan, and power LED lights in the truck cap. I don't yet have a fridge/freezer but anticipate getting one. That's about it. I've explored the in-cap AGI battery approach and read that even such sealed batteries give off toxic gases so I'm not excited about doing that...but am open to information to the contrary I may not have seen.

As you might imagine, I geek the stuffings out of this.

40Ah is not a lot in the cosmic scheme of things, but you can make it go further by:

-- Charging everything you can with 12v DC. You wrote "converter" but I suspect that you mean inverter. Remember that these beasts have significant (5-15%) loss and idle draw. Use the smallest inverter you can and only use it for loads that absolutely require 110V.

-- If your laptop cannot be charged on DC (e.g. a MacBook), try to charge it while driving rather than while on battery alone.

-- Even the very best coolers want about 20Ah a day. With only 40Ah available you will need to look at solar right from the start if you want to be parked for 3-5 days.

Remember that the wire run from the battery to the inverter is going to be BIG.

Parthian shot: Most dual/camper battery systems fail because:

-- The camper battery is too small and gets drawn down too much, and,

-- The battery never gets fully recharged. Solar is your friend, as is a good quality inverter/charger. An inverter/charger, plugged in at home, is a great way of assuring that your batteries get a full, multi-stage charge.

As one wag put it, most batteries don't "fail," they are murdered.

N.B. This battery is the same height as the battery you are proposing. It is larger, but if it will fit your tray, it will give you 10Ah more and it costs less on sale. http://www.vmaxtanks.com/MR127-100-Deep-Cycle-High-Performance-AGM-Battery_p_24.html

Best wishes.

 

[Smoky]

Verkstad...I'm willing to drill into the bed as I've budgeted for several hours of therapy to help me accept it.

I've read where sealed enclosures can concentrate hydrogen, thereby creating a potentially explosive situation. Since I wouldn't likely be able to anticipate a malfunction, I'll just go the safe route and install the battery in the engine compartment. As you can see, I'm pretty risk-averse.

In terms of the fusing...yes, absolutely...I'm doing my homework to ensure that everything is properly fused...wouldn't have it any other way!

 

[Ducky's Dad]

If your truck is a gasser, there may already be an extra, unused battery tray under the hood for diesels. My 1998 GMC 5.7 came with the extra tray in place and empty, so easy to mount a second battery. If you don't have the second tray, might be wise to get one. You can probably fit a Grp 65 or maybe a Grp 31 AGM in there if it is anything like my truck.

 

[Smoky]

Verkstad...I'm willing to drill into the bed as I've budgeted for several hours of therapy to help me accept it.

I've read where sealed enclosures can concentrate hydrogen, thereby creating a potentially explosive situation. Since I wouldn't likely be able to anticipate a malfunction, I'll just go the safe route and install the battery in the engine compartment. As you can see, I'm pretty risk-averse.

In terms of the fusing...yes, absolutely...I'm doing my homework to ensure that everything is properly fused...wouldn't have it any other way!

 

[Smoky]

DiploStrat...hey, that's a GREAT idea about the VMax MR127-100...thanks! One thing I should've mentioned is that my traveling style rarely involves staying parked for more than a couple days as i like to keep on the move. I've been sniffing out compact solar systems...just haven't settled on whether I want to install one as a permanent feature of the truck, or make a portable system for additional applications. I'll certainly take your suggestion about charging my laptop (which IS a macbook). As you point out, that would really help with the power draw of a fridge/freezer. Thanks again!

 

[Smoky]

It's a gasser...5.3 V8. It had the space for the second battery - passenger side in the corner by the hood hinge - but no tray. I recently purchased and installed the tray, and it looks like it'll work well.

 

[Smoky]

Also...here are the components I'm looking at for my dual battery setup...comments, criticisms, and suggestions welcomed!

Vmax MR127-100 Deep Cycle Battery (thanks to DiploStrat)

Samlex SSW-600-12A, 600W Pure Sine Inverter

Hellroaring BIC-95150B Battery Isolator

Appropriate cabling (0 or 1 to truck bed) and fusing

 

[DiploStrat]

Also...here are the components I'm looking at for my dual battery setup...comments, criticisms, and suggestions welcomed!
...
Hellroaring BIC-95150B Battery Isolator

I would not use a diode isolator with a gun to my head. Your GM truck has an excellent battery charging system, install an intelligent relay (I like Blue Sea's ACR line.) and you will be happy.

Install a diode isolator and you will have a dead battery or two. If you don't check the data on my website, at least read this: http://www.smartgauge.co.uk/facts.html

As to solar - save yourself a lot of time and trouble and go with at least 200w, permanently mounted to your truck. My system was sourced from these folks: http://www.amsolarrv.com Others may be less expensive but Greg and his crew really know what they are doing.

FWIW: It is 82F inside my camper and I am parked in woods with dappled shade. My batteries are fully charged from shore power last night.

I am am running two fans and the NovaKool refrigerator. With 500w of panels, in the shade, I am pulling down about 5A. With the draws of the fans and the refrigerator I am deficit about 3A, so that means that the total draw is about 8A at the moment.

Some real world numbers for you to consider.

 

[Smoky]

THIS is why I joined this forum...it's littered with people who know infinitely more than I do.

Thanks

 

[Smoky]

DiploStrat, what is your opinion of the portable power management systems - Engel Battery Box and ArkPak - as alternatives to an in-vehicle dual battery system?