Battery Bank Connections...

2Guido

After reading the posts on the "Sparking battery connection", I have a question...My Battery banks are 4x 6V AGM in series PER Bank with 2 Other 24volt Banks interconnected. I am using the regular Heavy Duty Battery Posts to interconnect the 4 AGM's, with 2/0 Copper, BUT, when tying all three banks together, I am using 4/0 cable tied to the secondary Battery Posts. The Inverters and Charge Controller all tie into the large Battery Terminals. Should I be tying the Banks together using the major Battery terminals also ??

Blackcherry04

Re: Battery Bank Connections...

I saw that " post" , no pun intended, more hand wringing from some Internet rumor parroted from forum to forum. The posts are throw backs to a automotive age and standard that someone started and was copied over and over and now on dual purpose batteries. The lead tapered posts are about the worse connection you can have in my opinion. If your amp draw is under 500 amps I wouldn't worry about it.

That said, I am not a fan of wing nuts on them and you should use Lugs with the proper size holes. Using the wrong size can pull the bolt posts out of the lead when tightened.

Cariboocoot

Re: Battery Bank Connections...

Agreed. Blackcherry is spot-on. There is no reason why the "auxiliary" connections can not handle the current of the big posts. These were original included for "dual purpose" batteries that might be used either in automotive applications where the posts were needed or in marine applications where the bolts were needed. Quite a number of batteries have only bolt connections and frankly they can feed hundreds of Amps just fine.

And yes you probably can't get wing nuts tightened down properly: use something you can get a wrench on.

Blackcherry04

Re: Battery Bank Connections...

Enough cannot be said about proper terminated Battery connections, they are everything. Attention to detail will pay off long term. Using a capable crimping tool is important, one with 8-12 tons of force and then use a adhesive lined Heat Shrink too prevent corrosion in the crimp and to keep acid from wicking up the cable. While you can get away with sloppy cables somewhat in series bank, it's the kiss of death in a parallel system.

Once a year a bank should be dissembled and each lug and connector wire brushed or sanded and re-coated with petroleum jelly / grease to keep intrusion of acid out. It's a pay me now or pay me later, you'll suffer if you don't. I like to number my batteries and shuffle them around when the Bank is apart, like rotating tires on a car.

I took a bank apart yesterday, it had heat shrink, but it wasn't adhesive lined. The cables had wicked acid and they were corroded at least 4 " up each cable. Whatever the guy paid for them it was a waste of time and money and performance of the system. Anytime the cable gets stiff around the lug look close, you might have a problem. The tightness of the connection is important, I torque all battery connections to 13 ft lbs, takes the guess work out of it.

Attention to Detail

Here is a 1000 words, wrong heat shrink. This what I found when I cut it open. The blue is the heat shrink. By the way, they were 3 years old, I didn't make them. I remember that he asked me, he thought mine were to expensive and he found someone cheaper. He got 2/0 and a cheap cable, wrong size lugs ( 3/8" and he has 5/16 " ) and now he has to buy another set, my price is the same.

Attachment not found.
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tons001

Re: Battery Bank Connections...

Blackcherry04 wrote: »

Enough cannot be said about proper terminated Battery connections, they are everything. Attention to detail will pay off long term. Using a capable crimping tool is important, one with 8-12 tons of force and then use a adhesive lined Heat Shrink too prevent corrosion in the crimp and to keep wicking in the cable out. While you can get away with sloppy cables somewhat in series bank, it's the kiss of death in a parallel system.

Once a year a bank should be dissembled and each lug and connector wire brushed or sanded and re-coated with petroleum jelly / grease to keep intrusion of acid out. It's a pay me now or pay me later, you'll suffer if you don't. I like to number my batteries and shuffle them around when the Bank is apart, like rotating tires on a car.

I took a bank apart yesterday, it had heat shrink, but it wasn't adhesive lined. The cables had wicked acid and they were corroded at least 4 " up each cable. Whatever the guy paid for them it was a waste of time and money and performance of the system. Anytime the cable gets stiff around the lug look close, you might have a problem. The tightness of the connection is important, I torque all battery connections to 17 ft lbs, takes the guess work out of it.

Attention to Detail

Do you need any special cleaner when dealing with the lugs like I see everyone mentioning or will a simple hitting it with sand paper work just fine? I am getting ready to install my bank and there is a tiny bit of corrosion on two of the positive terminals.

Blackcherry04

Re: Battery Bank Connections...

tons001 wrote: »

Do you need any special cleaner when dealing with the lugs like I see everyone mentioning or will a simple hitting it with sand paper work just fine? I am getting ready to install my bank and there is a tiny bit of corrosion on two of the positive terminals.

I just use a wire brush on them. I have seen people dip them in " Coke " . Sometimes there will be a build up where it has eaten through the tinning and I scrape it off with a utility knife and re-brush.