Adding aux/'house' battery, with self jump potential

[tshephard]

OK. RCSB - decided against invertor in cab - too premium a space.
Got it in 'behind' passenger fender vent - fairly high for wet, terminals almost at OE battery. near aux/house battery.

So, I'm gonna' run a parallel battery, with a big switch to 'join' the hots while running/charging or 'jumping' - otherwise open, separate circuit for 'house'/winch battery.

My concern is the ground, and the negative flow sensor. The added circuit will, very occasionally, hit 400amps for a few seconds. I'm a real Master Electrician in VA, I got the specs for cable, fuses, connectors, etc. I plan on a copper bar from the negative terminal to add the invertor and aux battery cables.
But, should I connect beyond the flow sensor(directly to battery negative, my occasional loads would never be seen) or in front of the sensor - so occasional loads would be seen through the sensor.
The battery system will be - in order of use frequency - house (12 v frig, lights, toys) OR invertor (for field tools) OR winch/jumps (hopefully never!). So the most 'popular load will be keeping 12v frig running.

Should I wire so ECMs 'see' the occasional loads or work 'around' it.
(I do like my Start/Stop system.)

THX guys!

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[Mszczewski]

I would be interested in seeing photos of what you have installed.

 

[tshephard]

I would too, but it's 'behind' the fender.
I cut 2x2 alum 1/8 angle about 8 inches long to 'hang' a bracket off the hood mount bolts, down the fender space. 3 bolts in flange to invertor for weight/support, and then a single 'bolt' in a lower invertor hole to a convenient structure (firewall?) 'flange' so no vibration.

I am consumed by the space wasted in modern truck design by body panels shaped for 'truck visuals', then backed by squared off interior spaces - with 3, 6, 8 square feet of 6 to 10 inch deep space just wasted, and 'almost' inaccessible.
So far I have I hidden my compressor in the passenger rear-most bed 'fender well' space , and now this in front fender well space.
I feel like the spaces are limited to rigid things that do not move (rattles, etc.) so no general storage yet, and things that are light enough for me to mount/remove one handed, JIC.

 

[tsigwing]

Would be concerned with placing those inside fenders. They tend to not fair well in accidents.

 

[FirstFord]

Should I wire so ECMs 'see' the occasional loads or work 'around' it.

Your question strikes me as being more philosophical in nature, rather than technical. And as such, there is no "correct" answer - it's your call. But considering what you are trying to do, I'd bypass the ECM. The purpose of the auxiliary battery and inverter is divorced from the mission-critical purpose of the truck. I'd rather keep them separated. But that's just me, and I am sure there are plenty of people who may disagree with me....

 

[timshephard]

FF, I'm gonna' have to agree.
I did see where jump starting the F-150, the ground would go to the bulky part of battery terminal, bypassing the current sensor. (And I would imagine, upon starting, would begin charging the other vehicle's battery, as well as the F-150's, so exactly my scenario.)

t - I ordered fuses today for every possible 'source' wire - JIC in case of accidents. The 'jumper cable' between the Aux and the main gets one at each end - as that cable could be sourced from the Aux battery, or the main IF I wreck while recharging Aux. (like a fusible link at both batteries to that one heavy cable)

THX, guys

 

[Mszczewski]

I would too, but it's 'behind' the fender.
I cut 2x2 alum 1/8 angle about 8 inches long to 'hang' a bracket off the hood mount bolts, down the fender space. 3 bolts in flange to invertor for weight/support, and then a single 'bolt' in a lower invertor hole to a convenient structure (firewall?) 'flange' so no vibration.

I am consumed by the space wasted in modern truck design by body panels shaped for 'truck visuals', then backed by squared off interior spaces - with 3, 6, 8 square feet of 6 to 10 inch deep space just wasted, and 'almost' inaccessible.
So far I have I hidden my compressor in the passenger rear-most bed 'fender well' space , and now this in front fender well space.
I feel like the spaces are limited to rigid things that do not move (rattles, etc.) so no general storage yet, and things that are light enough for me to mount/remove one handed, JIC.

Even more I now want to see how you mounted that in the back and where exactly.

 

[tshephard]

All right, when I get my cables done, and have to hook 'em up, I'll get pics. But, "in the back", did you mean compressor?

 

[Mszczewski]

Yeah, the compressor.

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