Brian’s Morning Newsletter

Thursday, April 22nd 2010

Good Morning
In an attempt to pull myself out of this emotional slump sciatica has tossed my head unceremoniously into, I’m making this morning’s newsletter be all about doing something.

In a two birds one stone effect this BMN will also serve as a new webpage at www.outfitnm.com. Some of you may have seen some of this before, as the process of wiring the new bank of 12 batteries had five month learning curve. I’m not saying I know everything, but I do know a lot more than I did last year, indeed this feels quite meritorious, yeah I need a little merit badge,

BMN Battery bank wiring

Wow, after many hours of surfing I can not locate the crimp lug I thought I saw a few months back at the first electrical supply place I saw. We own power lug crimpers, and made 6 cables for the series part of our battery bank.

These will interconnect the 12 volt batteries to bump the voltage to 24 like our Axial Flux alternator. Next I need to make the parallel interconnects. I had envisioned a copper bar, perhaps made of crushed pipe, but that was coming together and Spring is our traditional windy season.

Anyway I went back to looking for a lug with two cable ends creating a daisy chain effect. I can’t believe this doesn’t exist, the alternative apparently is two lugs per battery terminal.

Many places have thousands of different lugs, like here: http://www.elecdirect.com/catalog/1c3c2ede-3bab-4199-85a9-29c951bb82cc.aspx

I mean these are sweet,

From http://www.delcity.net/store/Anti!rotational-Crimp-Lug/p_1009.a_1

the price is ridiculous (US$2+ per) and I would need two per terminal for the daisy chain effect I am after.  12 batteries this would be at least 24 lugs.

So I went surfin again,

Here is an awesome website if you don’t already know about it

http://store.electrical-insulators-and-copper-ground-bars.com/index.html

well, it’s awesome to me because I love non-ferrous metals.

Anyway, the copper bar stock is gorgeous, and really not that expensive.

I quote from their site” Thickness .250″ x Width .875″ x Length 36″ Copper Bar Silver Flashed, Alloy C11000, Manufactured to ASTM-B187, Half-Hard Temper, Full Round Edge

A-247-250-087-036 $47.92

I’d need two, one for the positive and one for the negative side so, a hundred bucks, hmmm, tempting, but they also sell battery cell interconnect straps:

Sigh so many options,

and all I wanted was a double ended crimp lug so I can use the crimpers and cable we already own.
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That’s some pretty great research you did though. I’m saving the info. Have you tried any of the larger welding supply houses, or go directly to the manufacturers? such as Miller electric, or Lincoln electric?
Peter
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I think 2 lugs per terminal is pretty standard fare for RE battery systems. I actually found 2/0 lugs in stock at my local NAPA auto parts house last time I went checking.
Volvo Farmer
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I’d suggest the copper.  Try to find some big heat-shrink that you can wrap the areas between terminals, too.  Looks real “pro” when you do that.  Plus you can take the bars off a couple of years from now, strip the heat-shrink, and clean the oxidation off.  Can’t do that with a crimped lug, without cutting it apart.

Alternative: Maybe phone these guys:

http://www.go-rv.com/coast/do/catalog/page?pagePrev=TRUE&dealerId=1392&pageNum=47

I know I know – wrong side of the border – just suggesting you look at auto/RV supplies for your terminals.
Sparweb
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Interconnects have always been an issue for me. My first set were Aluminium simply because I had a reasonable amount readily available. A word to anyone who has similar thoughts – DON’T. They’re nothing but trouble!

My next set were scrap copper and were great (and 100% trouble-free) for the next 4 years.

I’ve just (this week) upgraded my battery bank and was faced with the same “what do I do for interconnects” question.

I rang around and visited an industrial switchboard manufacturer in the next town. He ordered me some “small” bar – he doesn’t use this “little” stuff any more. So I got two lengths (8 metres, about 25 feet) of 25mm (1″) by 6.3mm (1/4″) bar.

(Click photos for larger view)

Cutting the bar into 125mm (5″) lengths. The bandsaw made this SO much easier than last time, cutting them all by hand!

A small handfull of cut bars (for scale)

Drilling the links. There is a chunk of bar clamped inside the vice jaws to make a stop so I can drill accurately without having to mark each bar seperately.

They don’t look very shiny in this photo, but they were really. This is half of the links, finished.

Nice to have the tools to set the nominal bolt torque right.

The completed bank. These are 2V 500AH cells in two parallel strings of 24 cells each for 48V, 1000AH (48 KWH)

Viewed from the other end.
Ross
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I’d put some sort of cover over those strips – just in case you’re moving something conductive and it bumps into them.  (FLASH!)

Maybe a strip of plastic.
Ungrounded LightningRod

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Hey Boss,

look this number up on mcmastercarr.com  website, 88865k311 its the same as what you have listed above, except 1/8 inch wider, (silver plated, rounded edges, 1/4 thick, 1 inch wide, comes in 36 inch lengths) and at half the price of what you found. $26.68 each.

or the same thing in a 6 foot long bar, 88865K41 price $47.65, not a big price difference over the (2) 36 inch bars, shipping should be the same for both so 1 long bar or 2 short.

I tried to copy direct links to these but it doesn’t work because of their search method on the site, sorry

Matt
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Hey thanks everyone, it is good to know I’m not alone and belong in this group with its vast knowledge.

Yes sir those copper straps are pretty, how does that work with the battery terminals on the side like that, Ross?

I finally broke down after a tough day working outside in the super strong northern New Mexico Spring wind on Friday and bought the Del City anti-rotational lugs

“Anti-rotational Crimp Lug

Designed for top post and side mount batteries Stackable for multiple battery hook-ups; stacked terminals can lock at 24 different positions for easier cable routing  36 “teeth” bite into the metal so the terminal will not rotate

Terminals of different gauge sizes will easily stack and lock to each other.     Lugs crimp with crimper no. 990000 (all sizes) or 990005 ”

Check out this video if you don’t own the crimpers,

Solder slugs can also be used for installation     click here to view proper solder slug use ” http://www.delcity.net/documents/movies/battery_terminals.mpg

Before I pulled the trigger on the lugs, 28 of them, I called by buddy with the cable, and got him to read off the wire size “#2 AWG,” he said. Awesome.

The whole order is ~$75 I got a couple extra just in case.

These crimp lugs are color coded so it is easy to pick the proper die for the crimpers

I still want to buy some copper, it seems like a great investment, stuff even looks like gold

Anyway, for my next act, I am fairly certain of this, will take any feedback I can get, but like the farmers say, “we’re burnin’ daylight.” In our case the  wind is a  blowin’

AIMS 2500 Watt Power MSW  Inverter 24 Volts

Model #:PWRINV25K24V $249 from the inverter store,

but I may go with the less efficient pure sine wave inverter of less wattage, so I can feel better about plugging the refrigerator into it, if there is enough power.

AIMS 1500 Watt, 24 Vdc, Pure Sine Wave Power Inverter. FREE Remote.

Model #:PWRI150024S

I know these are like toys compared to Xantrec and Outback, but we don’t have the cash to spare, and these are in the range of my bank account

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Interconnects are in and sealed cell batteries are charging

I need to change the voltage on our Ghurd’s diversion load controller to work with sealed cell batteries
What voltage is recommended?
Brian Rodgers

Okay here is a twist, I was wondering why I hadn’t been complemented on the beautiful wiring, to find the answer, and learn why nothing comes easy read on, Brian

Is it intentional to leave no “breathing room” (air space) around your cells?

Do you consider there’s any serious risk of cells overheating being stuck hard up against each other with only one and and the top, to help dissipate any excess heat during charging or discharging?

What’s the “general view” for cell spacing?  Ross
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Oh, dear!  You’ve got both the + and the – fed on the same end of the row of paralleled cells.  That makes the battery nearest the feed do most of the work and the ones at the far end loaf.

For starters move either the + or the – feed to the other end, kiddy-corner style, as a much-improved first approximation.  Then search the board for one of the discussions on even better arrangements.
Ungrounded Lightning Rod
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Okay thanks Rod, currently I have the load on one  end and the turbine input on the other, I’ll switch around the leads today Brian
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I find this link very informative…

http://www.smartgauge.co.uk/batt_con.html
Sr WiNdTeCh
————

I like this statement  from http://www.smartgauge.co.uk/batt_con.html “I think I am right in saying that this is the only example I have ever come across where doing something the correct way actually looks less elegant than doing it incorrectly.” Bummer, but the logic is sound
So connecting diagonally helps some, but the third and forth examples are better.
Hmm, when does this learning curve give us a rest? Doubtless not even after we’ve built three or four of these systems, right? It is a good thing this RE stuff is more fun than anything else I’ve ever done.
The more I look at this layout the more I like it:
I take it the connections can have more resistance than the different cable lengths?
How would this work with 12 batteries though?

Keyword Suggestions?
I’ve been trying to locate the info I know I read before on the different voltages to set Ghurd’s dump load controller for sealed cell batteries, no luck on three tries.
Anyone know how well a google search is working for the new board software?
Brian from Tusas

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“battery loaf”
Rod
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ahaha…. You knew what would happen when I searched for that….  Sr WiNdTeCh

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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.
Rod
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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 Brian
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Easiest would be the 2nd Pos terminal and 5th Neg terminal.
Glen Hurd
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i was thinking something like that, or perhaps crisscross near the center  Brian
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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

Brian
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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.
Dan G
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This is how I interpret the wiring. I’ve left out the series connections for simplicity

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?     Brian
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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

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