Copper interconnect straps

[Sr WiNdTeCh]

ahaha.... You knew what would happen when I searched for that.... 

[Ungrounded Lightning Rod]

ahaha.... You knew what would happen when I searched for that.... 

Ah, I see.  Do it here and/or in quotes and all you get is the search term suggestion.  B-b  Sorry, I'm new to the software too.  B-)

A:  Take off the quotes
B:  Go up the tree at least to "Homebrewed Electricity" before you do the search.

That will get you to at least one of the longer discussions.  But it will still tend to find my summaries (rather then the postings that originally enlightened me on the need to do more than just kiddy-corner to get ideal balance) because I'm the one who tends to use the term "loaf" for the batteries that are doing less charging and discharging than their paralleled buddies.

[Boss]

Thanks for the links and now I have the positive input & load at opposite corners , but I am looking at how I can accomplish the arrangement I posted above with six parallel - dual (series)  12 volt batteries. from: http://www.smartgauge.co.uk/batt_con.html "Notice that for each individual battery, the current always goes through a total of one long link and one short link before reaching the loads."  Their arrangement makes sense, but adding two more batteries seems to mean I would need to stack more cable lugs per terminal, currently the bolts I have are too short for more than three.
I just need to stare at the pattern suggested alongside the picture of my bank and figure out a similar puzzle solution with the gear I have on hand, like the 8 unused  anti-rotational lugs I have left over from the original cable builds
Thanks for enlightening
   

[ghurd]

Easiest would be the 2nd Pos terminal and 5th Neg terminal.
G-

[Boss]

i was thinking something like that, or perhaps crisscross near the center

[Ungrounded Lightning Rod]

I just need to stare at the pattern suggested alongside the picture of my bank and figure out a similar puzzle solution with the gear I have on hand, like the 8 unused  anti-rotational lugs I have left over from the original cable builds

You have eight connectors left over?  You are in LUCK.  (Don't wreck any of 'em.)

Starting from the daisy-chained version:
 - Unhook both jumpers between batteries 2 and 3, and between 4 and 5.  (Discard or save for spares.)
 - Hook a new 4-hop-long jumper between + on battery 2 and + on battery 6.
 - Hook a new 4-hop-long jumper between - on battery 1 and - on battery 5.
 - Hook a new 2-hop-long jumper between + on battery 2 and + on battery 4.
 - Hook a new 2-hop-long jumper between - on battery 3 and - on battery 5.
 - Hook up the feeds to + on battery 2, - on battery 5.
(Remember that "N-hop-long" means N times the wire length as a short jumper,
even if that means more slop lying about.)

Worst case stack is four connectors on a terminal.

Every battery sees:
 - 1 hop-length carrying 1 unit of current.
 - 4 hop-lengths carrying 2 units of current.

If you had more connectors and more wire we could come up with something with a tad less drop.  But this is balanced and has less voltage drop than (9/15ths that of) the original version with the kiddy-corner mod.

[Boss]

Damn man this makes sense, I'll need to buy longer bolts, but that ain't no thing. I'll make sure to measure the new lengths to create multiples of the original lengths.

[Boss]

ULR wrote

(Remember that "N-hop-long" means N times the wire length as a short jumper,
even if that means more slop lying about.)

Am i nit picking when I wonder if the cable length of "N" includes the lugs, or will I measure from lug hole to lug hole and make this length "N"? In other words would it be okay to measure from crimp to crimp 

[DanG]

Once you get down to the millimeter you've done precision work, the only constant you can control is the length of wire.

Even if you duplicate each crimp sequence you're not going to keep the assembly from varying in length somewhat.

[Boss]

This is how I interpret the wiring. I've left out the series connections for simplicity

Starting from the daisy-chained version:
 - Unhook both jumpers between batteries 2 and 3, and between 4 and 5.  (Discard or save for spares.)
 - Hook a new 4-hop-long jumper between + on battery 2 and + on battery 6.
 - Hook a new 4-hop-long jumper between - on battery 1 and - on battery 5.
 - Hook a new 2-hop-long jumper between + on battery 2 and + on battery 4.
 - Hook a new 2-hop-long jumper between - on battery 3 and - on battery 5.
 - Hook up the feeds to + on battery 2, - on battery 5.
(Remember that "N-hop-long" means N times the wire length as a short jumper,
even if that means more slop lying about.)

Only problem I see when I am measuring this out is that where"N" equals one of the original lengths, it isn't long enough to reach
I could add ~ an inch, but it would be tight
How important are the actual cable lengths? I see that Dan G says a milimeter  is precise, how's this inch extra going to effect connectivity?
 

[Boss]

Alrighty then, the battery interconnects are sorted, thank you to everyone for your help

I had to mod two bolts to fit the connections where four lugs connect, after I realised there was going to be five cables, plus the #10 diversion load controller leads, I made one more interconnect for those and tied them into the main connector

From this angle you can see the receptacle for the three cables leading from the tower making a easy to deal with disconnect for the tower in case I need to untangle the cable 


Here is the insulated battery box with its cover on.


Above the 2500 watt MSW inverter is doing a great job powering out 35 inch CRT TV, home theater amp, DVD and our favorite new device the Roku Internet streaming video router. Above right is the three blade kill switch for the turbine, rectifiers on an recycled amp heat sink

[Peter-]

ULR wrote

(Remember that "N-hop-long" means N times the wire length as a short jumper,
even if that means more slop lying about.)

Am i nit picking when I wonder if the cable length of "N" includes the lugs, or will I measure from lug hole to lug hole and make this length "N"? In other words would it be okay to measure from crimp to crimp 

Boss -- I *always* measure from lug hole to lug hole. Like center to center. Because think about it like this: It's a lot easier to cut out some extra, than it is to add some back in. This way you got some slack to work with. With really big DC power like this, it's better to have a few inches extra on the cable instead of having to splice it. The losses are lower. Kinda like wood-working and metal-working: measure twice, cut once.

When I worked as a welder, it added up at the end of the month: a hundred-foot cable with a splice cost more to use and it showed up in the company's power bill, even though it was just a tenth of an ohm.

[ghurd]

When I worked as a welder, it added up at the end of the month: a hundred-foot cable with a splice cost more to use and it showed up in the company's power bill, even though it was just a tenth of an ohm.

I am not disputing you believe it.
Not sure I believe it.

Welding with 120A, 8 hours a day, 40 hours a week, 4 weeks a month, is about $25, maybe $50?
Moving assemblies/parts/cables/items/etc, fitting parts, rearranging, etc., be pretty lucky if an electrode was struck 1 hour a day?  $3 to $6 a month.  The bulb in the Coke machine uses more than that.  The new guy they hired, a slacker, who spends half the day making fresh coffee, uses more than that, but he got hired and fired while you were using the spliced cables?

Or, a sustained 1440W power dissipation in 1~2" of cable is going to cause some issues before the electric bill arrives.
G-

[Peter-]

I am not disputing you believe it.
Not sure I believe it.

Welding with 120A, 8 hours a day, 40 hours a week, 4 weeks a month, is about $25, maybe $50?
Moving assemblies/parts/cables/items/etc, fitting parts, rearranging, etc., be pretty lucky if an electrode was struck 1 hour a day?  $3 to $6 a month.  The bulb in the Coke machine uses more than that.  The new guy they hired, a slacker, who spends half the day making fresh coffee, uses more than that, but he got hired and fired while you were using the spliced cables?

Or, a sustained 1440W power dissipation in 1~2" of cable is going to cause some issues before the electric bill arrives.
G-

[/quote]

Actually Ghurd it did happen just like that. Myself and my guys were striking an arc much more than that, (every few seconds) and the company was particularly cheap: they watched every penny literally. To be fair, it was privately owned and not traded, and electric rates are fairly high here in upstate NY. I had to educate the big bosses about how to do things since welding was only a very small part of their business -- it was not the main thing. Even though I was the "leading man" in that dept.

We used anywhere from 120 to 500 amps of DC for at least 8 hours a day, 6 days a week. The building was fed with 600 VAC 3-phase and the welders used 480-volts 3-phase. It was difficult because be had to carry this current over a long distance, being a construction company basically.
If things were busy in the summer, then it added up fast and the big bosses would figure that into the bill. They had an 150-foot 3-phase 4-wire extension cord on a spool, and you had to drag that out to the site along with a few hundred pounds of welder machine.

I told them to get diesel generator-welders, but they never did. It was all about the up-front costs.

[ghurd]

Myself and my guys were striking an arc much more than that, (every few seconds)

We used anywhere from 120 to 500 amps of DC for at least 8 hours a day, 6 days a week.

Exactly what I meant.

[Peter-]

Myself and my guys were striking an arc much more than that, (every few seconds)

We used anywhere from 120 to 500 amps of DC for at least 8 hours a day, 6 days a week.

Exactly what I meant.

I will shut up leave now then. But IMHO every little bit counts when you get into triple-digits DC amperes and long runs.