Zwy
Solar Wizard
Ran across a deal on a large Hoffman electrical box for $200 on Craigslist. I've been looking for something to house the two 48V 280Ah batteries I'm currently building for use in my house. I wanted something that was enclosed, could fit 16 cells long in a series string so it had to be around 49 inches long with any compression fixture on the cells. The box will have fire suppression installed plus smoke detection that will trigger the whole house. I looked at many options, then hit upon the electrical box and found this, note it is laying down in the back of the truck. I didn't get the forklift out today to unload it as the wind is blowing 30 mph. 
This is what it looks like opened.
My first intentions were to stand it up in my basement, then add shelves inside, I could have 3 48V banks with enough space in between shelves to remove an individual cell, 10 inches in between top of bank and shelf above it. I would have to have the threaded rod run thru the sidewall to tighten the compression fixture, I can fit everything in there but only have about 1/2 inch to spare on each end. I would just use the cabinet wall as one end of the compression fixture, saves on material too. The wall would be insulated from the cell sidewall like I always do on my compression fixtures.
But I was looking at it tonight and thinking why not lay it flat, cut it in two and then weld up the sides, making 2 separate boxes. The box opening is 57 inches tall. Laying this on it's back would allow the complete compression fixture and cells to fit inside as this would now be a chest. I would be limited to the 2 48V packs however with no expansion.
I could install up to 4 shelves closer together if I leave this all in one piece and have 5 48V banks. Currently our daily usage runs about 12 to 14Kw and days the dryer or dishwasher is run we see up to 18Kw for the day. PV array is 8.2Kw and the dryer or dishwasher would be run in the daytime and not without PV input. I'm not certain if we remain at the 2 bank size or not as I might add a garage on the house with electrical boiler to heat the floor with excess PV or add heat pumps in the house for use in the fall and spring. We heat with LP here, not unusual to see -30F in the dead of winter. If I were to heat with heat pumps in the dead of winter, it would require a ground source setup.
Knowing all this, would you consider halving this cabinet or leaving intact with the idea that future expansion down the road might be coming? Space is limited in basement. If we did add on to the house, all of the solar would be moved up in the garage area in a small utility room.
Just throwing this out there for opinions as some of you have been thru expansions and might shed some light on what you did.
This is what it looks like opened.
My first intentions were to stand it up in my basement, then add shelves inside, I could have 3 48V banks with enough space in between shelves to remove an individual cell, 10 inches in between top of bank and shelf above it. I would have to have the threaded rod run thru the sidewall to tighten the compression fixture, I can fit everything in there but only have about 1/2 inch to spare on each end. I would just use the cabinet wall as one end of the compression fixture, saves on material too. The wall would be insulated from the cell sidewall like I always do on my compression fixtures.
But I was looking at it tonight and thinking why not lay it flat, cut it in two and then weld up the sides, making 2 separate boxes. The box opening is 57 inches tall. Laying this on it's back would allow the complete compression fixture and cells to fit inside as this would now be a chest. I would be limited to the 2 48V packs however with no expansion.
I could install up to 4 shelves closer together if I leave this all in one piece and have 5 48V banks. Currently our daily usage runs about 12 to 14Kw and days the dryer or dishwasher is run we see up to 18Kw for the day. PV array is 8.2Kw and the dryer or dishwasher would be run in the daytime and not without PV input. I'm not certain if we remain at the 2 bank size or not as I might add a garage on the house with electrical boiler to heat the floor with excess PV or add heat pumps in the house for use in the fall and spring. We heat with LP here, not unusual to see -30F in the dead of winter. If I were to heat with heat pumps in the dead of winter, it would require a ground source setup.
Knowing all this, would you consider halving this cabinet or leaving intact with the idea that future expansion down the road might be coming? Space is limited in basement. If we did add on to the house, all of the solar would be moved up in the garage area in a small utility room.
Just throwing this out there for opinions as some of you have been thru expansions and might shed some light on what you did.
