I don't like drilling a hole through the floor and shoving a wire through. It's not weather proof, and if I ever need to remove or replace the wire, it makes it difficult. I did one like this before realizing how crappy it is. I haven't installed a house battery yet, but I'd like to soon, and I'd like to place it inside the main cabin and grounded to the closest frame member possible.
What are your solutions or ideas for adding a ground point through the floor to the frame? The first thing that comes to mine is a short length of all-thread, with washer and bolts above and below (to secure it to the floor), than bolt grounds with eye terminals. But I don't know if that's a bad idea for any reason.
I’d go heavy copper through the floor, bolted to frame like viks says. Use a squirt of silicone , though underneath holes really don’t get much water anyway. But if the battery is going inside make sure it’s compartment is well vented to the outside, or use a sealed (AGM) battery. Some even vent the sealed ones, but I’ve seen them work safely without extra vent.
I plan on putting it in a sealed battery box with a vent through the floor (with some kind of screen to prevent bugs from coming in). It just occurred to me that I could easily run the ground through the vent channel.
Additionally the battery box will be surrounded by 1/2" plywood on 3 sides, 3/4" plywood on two sides, and 1" of plywood on another. If in the unlikely scenario that the sealed AGM battery (in a sealed battery box with vent to exterior) still manages to explode, and plastic shrapnel is somehow powerful enough to get through all that plywood, I don't think having it immediately on the outside will make much of a difference. Either way, it's a level of risk I'm comfortable with.