Planning questions - new shop (5 Viewers)

[Tennessee Jed]

I'm going to build a steel garage and have a couple of questions. It's going to be a fully solar 12 volt setup, no AC supply due to cost and inconvenience. I live in the woods and it would require digging a long trench crossing utilities, a road, ditches, etc. Initially I'm planning on a 300ah LiFePO4 battery and 400 watts of solar. I should have dependable sun exposure.

1. Do you think I can run a small (125 amp) spool gun off of this power supply and a 3000 - 5000 watt inverter? I'm no big timer, and will only have it for small occasional jobs. If I did tackle something like a bumper or sliders, I'm fine with breaking the job up over several days. But if you think the battery will be dead in 5 minutes, I'll rethink this. I can also double this to a 2 battery setup with 600 ah later on if needed.

2. Is it a good idea to have the system grounded to the steel frame of the building? It'll set on a gravel base. Or should I sink a copper ground rod? Or is it fine to just ground it to the negative of the battery and not have any other ground?

3. Any ideas for 12v lights overhead? Ceiling height is 12' max. Most of the 12v ceiling mount lights are extremely fragile little deals intended for something like a kitchen cabinet. There are exterior RV scene lights as well as small light bars intended for bumper mounts (usually 4" - 6" long) that seem like they would be fine, but even the flood versions of these may wind up being more of a piercing beam of light rather than a more useful kind of area illumination you get from traditional long neon tubes.

4. The troopy will sit here days at a time sometimes which means no solar coming in to the trucks own panels, and I'm planning on keeping the vehicle accessory battery (which is completely independent of the starting battery) topped up from the shop system. This is to keep the fridge running, mainly. Any issues using just having a good size cable with an Anderson plug running off the shop panel, plugged in to the trucks charging plug? Don't know if there are issues using a battery to maintain the charge of another battery. The more I do 12v DC, the less I realize I know.

Thanks

 

[Bob Morazes]

Interesting idea.
You started me thinking about my own pole barn.
I wonder if a portable 5kw generator would be a better/cheaper solution.
You can get what ever you want done with ample AC power. and there is no need for dc to ac conversion and dc lighting?
And you can take it home if you lose power in a storm.

 

[Tennessee Jed]

I thought about that. And that might be the best option, for all the reasons you mention.

 

[thatcabledude]

Seems like a good scenario for a generator welder.

 

[WarDamnEagle]

I'm with @thatcabledude regarding power if you can't get power pulled. Are you sure you can't just go overhead? Have you asked the power company? Assume yes; but thought I would ask.

Also, you say you are building a "steel" building? Do you mean a red iron building? How do you do that without concrete or are you just pouring footings and having a gravel floor? Regardless, the building should be grounded if it's steel. Size matters so it might need grounding at opposite corners. I'm not an expert on the subject but there are guidelines - and I know enough to know if it's steel it should be grounded.

 

[Tennessee Jed]

No - not a red iron - a steel barn/garage type building, the ordinary "carport" type, only much larger and nicer.

I like the generator welder idea, but I think that's beyond the scope of what I'll need. I think I'll get a regular generator and use it to power the welder for the occasional uses I'll need it.

Getting power to the shop would double the cost of the project and I'm enjoying toying with the idea of straight solar. My needs are pretty minimal.