Deciding to DIY my solar battery was one of my worst mistakes ever

[Daddy Tanuki]

Anybody build a pc when windows Me was the operating system of choice?

Remember building pc's when windows 95 was first out?

Or BEFORE 95? Vista anyone?

Yeah... i love solar!

Windows 3.11 for workgroups... that would have been around 1993 or so...

 

[Brucey]

that would have been my first marriage!

My wife's first husband, big into computer overclocking. Ended up drilling into freezer section of their fridge to eek out more performance.....so compared to that my solar shenanigans are of very low concern to her lol.

 

[Daddy Tanuki]

My wife's first husband, big into computer overclocking. Ended up drilling into freezer section of their fridge to eek out more performance.....so compared to that my solar shenanigans are of very low concern to her lol.

the lives we live huh?

 

[Brucey]

the lives we live huh?

Yes so consider me out of the running for any experiments like, "can a Victron SCC that's placed in a freezer outperform one at ambient 75F thats approaching the temp of the sun due to less derating?"

 

[Daddy Tanuki]

Yes so consider me out of the running for any experiments like, "can a Victron SCC that's placed in a freezer outperform one at ambient 75F thats approaching the temp of the sun due to less derating?"

Dunno, might be worth the doghouse for a night or two to figure that one out.

 

[Brucey]

Dunno, might be worth the doghouse for a night or two to figure that one out.

I do have a chest freezer I can empty, what happens in the power shed stays in the power shed ...

 

[G00SE]

Considering that buying prebuilt batteries would have cost me about $9k more, a couple of hundred Dollars of waste is not so bad, I think.

Also by using the savings on extra battery you can reduce the size of wire in most cases.
Example I have 4x 280ah batteries with 12kw inverter. The most one battery will ever see is around 60a. Wire size for that is reasonable

Why not wire oversized in that case so that if a battery or two gets pulled, you aren’t self limiting your power

 

[1201]

Why not wire oversized in that case so that if a battery or two gets pulled, you aren’t self limiting your power

You could do that.
Or buy more battery

 

[timselectric]

Why not wire oversized in that case so that if a battery or two gets pulled, you aren’t self limiting your power

You could do that.
Or buy more battery

Or both. lol

 

[Supervstech]

Windows 3.11 for workgroups... that would have been around 1993 or so...

Yeah, I upgraded TONS of systems to WFW, huge speed improvement over 3.1 disk cashing for the win!

 

[G00SE]

You could do that.
Or buy more battery

You had me spitballing an idea to save some money but I think I’ll stick with 2/0 from battery to bus lol
4/0 from bus to inverter

 

[1201]

You had me spitballing an idea to save some money but I think I’ll stick with 2/0 from battery to bus lol
4/0 from bus to inverter

2/0 from battery to busbar? How big is your inverter and how many ah of batteries are you planning?

 

[Supervstech]

I'm old enough to remember punch cards and being so excited to get an 80 column graphics card.
But all this talk of remembering back about building computers does remind me of the classic Monty Python skit about "back in our day" (which I am so guilty of).

Oh how times have changed. My kids equivalent to "when dinosaurs roamed..." is "the olden times like when phones were stuck to the wall."

Back on topic. For me, I really enjoy the discovery and tinkering of DIY.

Luxury. They were lucky!

 

[G00SE]

2/0 from battery to busbar? How big is your inverter and how many ah of batteries are you planning?

4-15kwh batteries each with 200ah BMS
10kwh inverter
Each battery has a disconnect so I can run max or close to max output from a single battery if required

 

[1201]

4-15kwh batteries each with 200ah BMS
10kwh inverter
Each battery has a disconnect so I can run max or close to max output from a single battery if required

Ok I don't see a world where you have 4 batteries but switch down to only one but if that's a possibility then it is what it is and you size your wire accordingly.

 

[G00SE]

Ok I don't see a world where you have 4 batteries but switch down to only one but if that's a possibility then it is what it is and you size your wire accordingly.

Oh I sure hope I don’t encounter a situation that would leave me down to one, but if there is…..!

 

[Daddy Tanuki]

Ok I don't see a world where you have 4 batteries but switch down to only one but if that's a possibility then it is what it is and you size your wire accordingly.

drop three out for emergency maintenance... leave one running to keep wife happy.

 

[Aak]

Mainly research is what's time consuming. Currently I'm trying to figure out the correct torque figure for the battery fixture I created. One person on this forum says:

"300 kgf looks to me to be 660 lbs of clamp load. 25 in/lbs of torque on 5/16-18 threads"

another guy says:

"The spec from EVE was 300 KG force which rounds off to 660lbs. Battery face is approx 6.85"x 7.874" = 53.94 sq inches
660lbs/53.94sqin=12.23 lbs per sq inch
Divide 660 by 4 bolts that's 165 lbs Axial (clamping) force per bolt.
Using 4 course 1/4 in threaded rods that should equate to roughly 8 INCH pounds torque per bolt. Realistically, that's a snug twist of the wrist on a regular nut driver for the average build mechanic."

So 1 person says 25 in/lb, the other says 8 in/lb, I don't know which is right. If anyone in this thread happens to have authoritative information, that would be great. My fixture is using 6 threaded rods.

hope this helps you.

 

[Aak]

i hope this chart helps people also a dab of Loctite is a very good idea when building battery's or any connections

 

[Crowz]

LOL... lucky you... I had to use a soldering iron to build my first computer. Not just for connecting bits together, but soldering all the components to the PCB... Yes, I am that old

Lucky you. I started out with bread boards PCB's were a ways off for the home market then.

On a plus note fixing the commercial stuff was easy since the traces look like interstate highways compared to todays multi layer microscope need to see things.