Drilling into battery compartment

I did the same thing. Added 4ga 100amp charging circuit to my truck to the batts. I can't say what's in yours, but what I did was drill a very small 1/8" "exploratory" hole to see if the bit hit anything.
In my case I could see from inside the camper I wouldn't hit wires or plumbing, and like you said, all I hit was Styrofoam and fiberglass.

**Make sure you run an automotive 100a or 80a circuit breaker on each end of your 4ga.**

If the wire gets snagged and shorts, the camper batts can start a fire just as easy as the truck batts. Putting breakers at each end will prevent it. Plus it makes it easy to just hit the disconnect on the breaker when you're parked to separate truck from TC batts.

I would add, do use a good Studfinder to see if anything comes up. They really have helped me make intelligent choices as to where to drill and where not.

While plugged into a/c, use a voltage sensor on both a/c & dc to check for wiring before drilling.

Artum Snowbird wrote:
I would add, do use a good Studfinder to see if anything comes up. They really have helped me make intelligent choices as to where to drill and where not.

Good suggestion. I'd like to drill "clean" through. Hopefully.

SDcampowneroperator wrote:
While plugged into a/c, use a voltage sensor on both a/c & dc to check for wiring before drilling.

Okay. Although, as I'm looking at it and from looking inside, I think I'm clear of all electrical.

Boatycall wrote:
what I did was drill a very small 1/8" "exploratory" hole to see if the bit hit anything.
In my case I could see from inside the camper I wouldn't hit wires or plumbing, and like you said, all I hit was Styrofoam and fiberglass.

That's precisely what I STARTED to do. but chickened out even then.:B

**Make sure you run an automotive 100a or 80a circuit breaker on each end of your 4ga.**

I have a 100A breaker, and was planning on installing it just after the truck battery, but hadn't considered using a second one at the other end. Good idea.

I'll be using a constant duty solenoid, activated via a (30A) upfitter switch. I believe the solenoid is either 85 or 100A. Would that be sufficient for the truck end and then install the 100A breaker on the camper end?

If the wire gets snagged and shorts, the camper batts can start a fire just as easy as the truck batts. Putting breakers at each end will prevent it. Plus it makes it easy to just hit the disconnect on the breaker when you're parked to separate truck from TC batts.

I know about this all too well. Many years ago, before I knew much of anything, I my employer had our trucks fitted with inside winches to raise and lower equip. Well, unknown to me, our "mechanics" had haphazardly ran wire directly from the battery, drilled holes using no grommets or insulation of any kind and called it good. One day, I'm on a freeway overpass (the long sweeping, turning kind) and I smell fire. I immediately identified it as electrical. Unfortunately, I'm traveling about 50 MPH with nowhere to pull off to. Then the SMOKE starts to roll. I can't see nuthin'. Then the engine dies. No power steering. "Uh oh!", I'm thinking. Luckily, I had enough momentum to get around the curve and stop. I grabbed my pliers (I always had a pair within reach, up front), popped the hood, and as quick as I could, somewhat loosened the battery terminal, and yanked it off. Only the wiring had caught on fire, but the various things surrounding it, could have easily went up, and the truck with it. I cut everything they "installed" and headed back to the shop, ready to chew some butt!

joeshmoe wrote:

I have a 100A breaker, and was planning on installing it just after the truck battery, but hadn't considered using a second one at the other end.GOOD IDEA.

I'll be using a constant duty solenoid, activated via a (30A) upfitter switch. I believe the solenoid is either 85 or 100A. Would that be sufficient for the truck end and then install the 100A breaker on the camper end?

No! The solinoid is rated at what it would pass, its working rating-not at what it will fail at. When the solenoid is energized creates a magnet that creates a physical connection between the in & out battery terminals, usually a copper bar. The energized coil/magnet is independant of the battery terminals passing current. It will continue to remain in contact, -passing current until either the coil is deenergized/turned off or something melts. Its probable that would be quite far beyond its rating. which more than likely wires or somthing else would go 1st. adding correctly sized fuse at both ends is...a good idea.

I figured, but wasn't positive. Thanks. Any other recommendations?

Forgot to mention that I'm running two 6 volt batt's. Does it make any difference vs. 12V, in the way that the charge line needs to be connected? Isn't it just one big 12 Volt battery?