240v, 241 what ever it takes....Inverter question.

I have not said much about my setup, it is in my shop and runs "most" things in the shop. I have this inverter, the small old one is just a backup. I actually don't even have it anymore I gave it to the in laws so next time they loose power for a week they can open the garage door and keep a fridge running for at least long enough to keep things from going bad. A fridge will hold its temp quite well if you leave the door closed.



I have it hooked up to this manual transfer panel. It is currently 120 only and the double breaker in the pic has now been split to just do 120.


Hooked into a "normal" panel. The tape letters go with what circuit is on the panel. This is why I say "most" things are on it.


The things that are not on it that I am thinking about is the 240 stuff. Some of these are high current like welders and plasma cutters. I will not run those off "battery", but I would really like to run the A/C. Perhaps the lift. I also want to power the barn, there are just some LED's in there for light, not many and several battery tenders for the mowers and tractors. This is on a 240 "feeder" to the barn from the panel showed above.

Now for the hard part.....I think, I want to stay 12v. I want to do this for several reasons, but the big one is availability of....stuffs. 12v stuff is everywhere, most campers have it, most motorhomes have it. And if the day comes when I can't find things and the internet is gone, I think 12v is going to be more easy to come by. I just want to stay this way, I think I have an understanding on the shortcomings of the 12v.

To just be clear, I am not a person doing this to "save the planet", I am doing this so I have power when the people on the planet start to act really nutty if you catch my drift.

My setup is also on this rolling Harbor Freight cart, currently 9 batteries, more from when these old photos are taken. This way I can roll it into the house and power things like the fridge freezers and all that jazz. There are also "medical" needs that require power. In a SHTF type deal people will not do well with no power.

I hope I explained that well.

The explanation is fine but you're just not gonna find much support for 12v here. It's unmanageable.

You're near the limit of what is manageable on 12 and the A/C is going to push it into unreasonable territory.

hwy17 said:

The explanation is fine but you're just not gonna find much support for 12v here. It's unmanageable.

You're near the limit of what is manageable on 12 and the A/C is going to push it into unreasonable territory.

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Well that is going to be something I need to think about. I could always roll up to 24-48 then when things fall apart I would have the 12v that would run on whatever I could find in the wild.

You did explain why my own research hit a dead end. I would like to stay under 48 if possible.

fpgt72 said:

Well that is going to be something I need to think about. I could always roll up to 24-48 then when things fall apart I would have the 12v that would run on whatever I could find in the wild.

You did explain why my own research hit a dead end. I would like to stay under 48 if possible.

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Trying to play devils advocate here.. If you're really interested in the availability of 12v stuff in a "just in case" scenario, but want the benefits of 48v for the larger AC loads.. you can always do the "4x 12v in series to make 48v" thing.

If something were to happen down the road, and you can't find 48v stuff, you can always split the batteries back into the 12v components, and scrounge up stuff that'd work with them.

When you buy SCC's, make sure you buy ones that can be set for 12v and 48v batteries, so they can be re-purposed if needed. So the only "difficult" part of this, would be the inverter. I'm not aware of any inverter than can take 12 OR 48v input. So, you'd likely end up with a 48v inverter, and maybe keeping your pictured 12v inverters on a shelf until that day comes.

With a 12 volt system and 9 batteries this tells me you have 9, 12 volt batteries in parallel. Your charging and discharging paths must be all over the place. This is certain death to your batteries. Let me guess, they are all different ages. Adding new batteries to older batteries in parallel is guaranteeing an early death to the new ones. The best way to build a lead acid battery bank is by getting the correct size (amp hour) batteries to build the battery bank with one string in series. If you have to have 1100 amp hours then buy 1100 amp hour 2 volt cells and put 6 in series for 1100 amp hours @ 12 volts

n2aws said:

Trying to play devils advocate here.. If you're really interested in the availability of 12v stuff in a "just in case" scenario, but want the benefits of 48v for the larger AC loads.. you can always do the "4x 12v in series to make 48v" thing.

If something were to happen down the road, and you can't find 48v stuff, you can always split the batteries back into the 12v components, and scrounge up stuff that'd work with them.

When you buy SCC's, make sure you buy ones that can be set for 12v and 48v batteries, so they can be re-purposed if needed. So the only "difficult" part of this, would be the inverter. I'm not aware of any inverter than can take 12 OR 48v input. So, you'd likely end up with a 48v inverter, and maybe keeping your pictured 12v inverters on a shelf until that day comes.

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This is what I have decided to do, String my 12v batteries up so I have 48, then box up my 12v stuff in a nice heavy steel box, I have a feeling you know where I am going with that steel box.

Just buy all new stuff for inverter and such.

Plus side if things do get spunky, I am a LONG way from a major city, but VERY close to a Primary target. If it gets that crazy I might see a flash for 1/10 of a sec before I am reunited with my old dogs. But just incase that primary target is not hit, I will be ready, and I will not care at all about AC.

littleharbor2 said:

With a 12 volt system and 9 batteries this tells me you have 9, 12 volt batteries in parallel. Your charging and discharging paths must be all over the place. This is certain death to your batteries. Let me guess, they are all different ages. Adding new batteries to older batteries in parallel is guaranteeing an early death to the new ones. The best way to build a lead acid battery bank is by getting the correct size (amp hour) batteries to build the battery bank with one string in series. If you have to have 1100 amp hours then buy 1100 amp hour 2 volt cells and put 6 in series for 1100 amp hours @ 12 volts

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They are set in 3 banks of 3. Those 3 are tied into bus bars, Lead from the bus bars goes to the inverter, and the charging is done to the busbar.

I think it would have been "better" to run the batteries all to the busbar but that is a bit of cable, so the 3 sets of 3. I am not sure what the life span of the batteries will be, it is an experiment, we will just see.

All batteries are bought in the same month, and installed over 2-3 months depending on my schedule. They are not lead acid LiFePo4 batteries, and all bought new.

You made quite a few assumptions in your post.

In a world ending scenario, how long do you think you'll need electrical stuff? When the last battery dies, then what? Don't get me wrong, I feel the imminent collapse looming, but I think spending tons of money on electrical equipment might ultimately be fruitless. Spending that money on ammo might be something to consider.

fpgt72 said:

They are set in 3 banks of 3. Those 3 are tied into bus bars, Lead from the bus bars goes to the inverter, and the charging is done to the busbar.

I think it would have been "better" to run the batteries all to the busbar but that is a bit of cable, so the 3 sets of 3. I am not sure what the life span of the batteries will be, it is an experiment, we will just see.

All batteries are bought in the same month, and installed over 2-3 months depending on my schedule. They are not lead acid LiFePo4 batteries, and all bought new.

You made quite a few assumptions in your post.

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And you know what they say about assuming things. my apologies there. It really helps to post all details about the system in question. Sounds like this may not be your permanent system but when you do settle on something that will be at least semi permanent it really helps to fill in the details in the Signature Line of your account.

littleharbor2 said:

And you know what they say about assuming things. my apologies there. It really helps to post all details about the system in question. Sounds like this may not be your permanent system but when you do settle on something that will be at least semi permanent it really helps to fill in the details in the Signature Line of your account.

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I am real new to all this, I am not sure what is relevant and what is not. I have however done electrical work for over 20 years, not professionally but just home stuff, and nothing has burned down or zapped me so something must be right.

No my setup is far from permanent. It was really done around a SHTF type deal. I had hoped to run the fridge and freezers over night in a long term power outage, save the propane as much as I can. In playing with this the thought crossed my mind you know why not hook it to the AC? And I started to look at that. It was not in the cards when I put this all together.

I did it on the cart so I could at least use it in the shop and if need be I can roll it to the house, and power those few things. Blower on the fireplace, and the food are tops on my list to stay alive.

Working in the shop over the hot summer with the AC on, and everything else on battery I thought you know it would be nice if............ So I started looking.