New Start/House Battery setup….using KISS

[The Brockerts]

New Start/House Battery setup….using KISS

I was going to the setup that Mike H. has on his Californian for the factory installed 4 8D batteries on my Californian. This change should only require a simple cable change. See thread and pictures below.

The basic setup is 2 8D’s for Port Engine and Generator, 2 8D’s for Starboard and House. Mike setup is 1 8D for Port and Generator, and 3 8D’s for Starboard and House.

I have a parallel Battery Switch at the Helm(tested and works) for the case where I run down the start/house back and can’t start the Starboard bank.

I don’t hang out much but would like the extra capacity since I’ve added and inverter/charger to run a refrigerator

In reviewing the current configuration, (see Pictures) I noticed that each battery has it’s own ground even though each bank is wired in parallel.
The reason for this extra ground wire is ?

So if I disconnect battery #4 and reconnect it in parallel to battery bank 1&2, should I add the additional ground connection too for the third battery ?
.
https://www.trawlerforum.com/forums...use-batteries-58401-post1012223.html#poststop

The Brockerts

Engine Batteries and House Batteries - Trawler Forum

 

[sbman]

Looks to me like a 'diagonally' wired bank. The idea is to pull negative off one end of the parallel bank and positive off the other end to help balance current flow through all the batteries. How well this works is debatable. I've initially wired my bank like that and see quite a difference in current flow between the middle batteries and the outer batteries, so the diagonal wiring isn't doing what I'd like it to do.

 

[Bacchus]

Heads up Re: Large Batty Banks

Joe,
I'll preface this with the caveat that I'm no expert on this but have been considering options for replacing my 2- 8D house bank when the time comes. I have read about ABYC fusing reqm'ts for large batty banks. Here is an online post from another forum I saved. I'll highlight the key point that may apply to you going from 2 to 3 8Ds for your house bank. In order to meet ABYC reqmts you may need to add appropriate fusing.
I'll also attach an article by Steve D Antonio, a TF Commercial Member and marine consultant.
Hope it helps or at least educates.

"Jim Healy via Trawlers-and-Trawlering
unread,
Aug 9, 2018, 1:46:26 PM


THIS POST IS JUST A HEADS-UP, RELATED TO THIS THREAD.
Last week, ABYC published their annual standards updates for 2018, including Standard E-11, AC and DC Electrical Systems for Boats. That standard takes effect in July, 2019, and it will affect many cruisers. I have spent the last couple of days reviewing the standard. There are only a few changes, but there is one that is quite significant.
Many, many cruising boats will need to look at fusing of their main battery bank(s). The 2018 E-11 Standard says the any DC system powered by a battery or battery bank (regardless of 12V, 24V, 32V) of greater than 500aHr capacity, THE BANK FEED(S) must be fused with a fuse rated at 20,000 Amp "Ampere Interrupt Capacity." The only fuses that currently meet that requirement are Type JLLN fuses made by a number of manufacturers. They are commonly marketed as Class "T" fuses. Class "T" fuses are available in chandleries in ratings from 125A to 400A. They are often found in inverter/charger feeds, but this new standard requires them in ALL FEEDS originating from large battery banks. NOTE: this includes the "charging feed" from the engine alternator to the battery bank.

The operative language is found in the 2018 section on "Main Battery Overcurrent Protection" in E-11. Following is the quote:
"11.10.1.2.3 For batteries or battery banks with a CCA rating greater than 2200 CCA, or 500 amp hours, battery overcurrent protection shall have a minimum ampere interrupting capacity (AIC) rating at least as great as the battery manufacturer’s short circuit rating or be rated at a minimum of 20kA at 125 VDC or higher."
Impact:
A boat with no more that two 8D batteries in a battery bank will not be affected, since the bank is less than 2200CCA or 500aHr.

Any boat with six, 6V golf cart batteries or more in a bank, or with more than two 8Ds in a bank, is affected.
Any combination of batteries of any size can trigger this requirement, including banks of Group 31 and Group 34 batteries.
Those currently protected with Type MRBF Fuses will no longer meet the criteria of the standard, since Type MRBF fuses are not rated at 20kA AIC.
I do not have any insight into why this change was made. I do agree that the change does improve electrical safety and DC system security. I have no idea how this will affect individual boat owners, but it could be significant if called out as a survey finding in future years.
AGAIN, JUST A HEADS-UP, FOR AWARENESS. Those working on electrical system upgrades are urged to plan for this.
Jim
Peg and Jim Healy aboard Sanctuary, currently at Charlotte Harbor, Punta Gorda, FL
http://gilwellbear.wordpress.com
Monk 36 Hull #132
MMSI #367042570
AGLCA #3767
MTOA #3436"

 

[SteveK]

Don, Thanks, good info filed away.
The main reason suggested for this latest change is to prevent fires onboard.

It reminds me back when I was building homes and had inspectors inspect something new and different each month to justify their existence.
ABYC keeps reminding me of this because the new has been around for many decades but now a special fuse is needed.

 

[ranger58sb]

The operative language is found in the 2018 section on "Main Battery Overcurrent Protection" in E-11. Following is the quote:
"11.10.1.2.3 For batteries or battery banks with a CCA rating greater than 2200 CCA, or 500 amp hours, battery overcurrent protection shall have a minimum ampere interrupting capacity (AIC) rating at least as great as the battery manufacturer’s short circuit rating or be rated at a minimum of 20kA at 125 VDC or higher."
Impact:
A boat with no more that two 8D batteries in a battery bank will not be affected, since the bank is less than 2200CCA or 500aHr.

It's easy enough to find 8Ds with greater than 1100 CCA, so pairs would be greater than 2200 CCA.

Our engines want a minimum of something like 1425 CCA per battery in a 24V pair.

Just suggesting the blanket statement -- "A boat with no more that two 8D batteries in a battery bank will not be affected" -- is likely subject to "it depends."

-Chris

 

[Bacchus]

It's easy enough to find 8Ds with greater than 1100 CCA, so pairs would be greater than 2200 CCA.



Our engines want a minimum of something like 1425 CCA per battery in a 24V pair.



Just suggesting the blanket statement -- "A boat with no more that two 8D batteries in a battery bank will not be affected" -- is likely subject to "it depends."



-Chris

No argument with the 8D CCA specs and cut off.
I picked that up as a quoted post and didn't want to start editing someone else's post. Steve D Antonio article has more detail if you read through it.

 

[The Brockerts]

I can see this project is going to be an educational experience.

First, seem like everything in my electrical path would burn up before 20,000 amp’s is reached.

Problem 1. I can not find any fuse for my 3208’s like I can for my Generator. (See picture) My Generator has a 250 amp fuse. I have 1 40 IGN fuse for each engine. That’s all I can find.

Given that a “short” during starting cranking could be a problem and the more battery bank you have the more CCA and therefore a need for a 20,000 amp fuse?

Is that that correct?

 

[C lectric]

THere is more to fusing than what I see discussed here. I have not read Steve DeAntonios article yet.

I am no expert but the high current interrupt capability is needed often because it does not matter about your loads. In situations where at the battery fusing is needed the loads have nothing to do with anything.

The batteries themselves can supply THOUSANDS of amps in the case of what is termed a "Bolted Short Circuit".

Although most of us will hopefully never see it, there is a possibility that if a large wire is shorted to ground through a heavy ground which also has a large wire going back to the battery those batteries would supply far more current than the so called CCA ratings. The wires may melt or burn but sometimes worse is the batteries themselves can explode.

If the fuse itself is not the right type the fuse link can vapourize and explode which ionizes the air which then itself becomes a conductor and continues to conduct even though the fuse has blown. I have seen fuses literally explode because someone thought it fits and that is all there is to it, wrong.
That's part of the reason there are so many different types of fuses with different interrupt ratings beyond just the conducting amperage rating.

In your case you have a + bussbar with branch fuses to various loads.
Just below and to the side a bit is the - bussbar. If for some unforeseen circumstance a wrench for example was dropped and bridged between the two busses, the + & - there is now no fusing to protect the feeds OR you from the resulting fireball unless there are battery fuses next to or at the batteries.


These kinds of shorts or problems can result in a fireball of short but very violent action often burning those nearby or explosions. I've not had personal experience but I have seen the results of something like this. THe guy was dammed lucky he was not blinded but he suffered burns that left him with the equivalent of third degree burns on his face and hands.
His glasses saved his eyes. but they had to be replaced. Debris had melted the glass lenses.

The fuses stopped the short but not before the fireball erupted burning him badly. In this case the fuses were rated though for this type of accidental occurance.
We thought a bomb had gone off, literally.
Yes a different system, higher energy, but 12 or 24 systems can erupt like this also. I have had experience with exploding batteries. Got lucky though.

I strongly suggest the use of a piece of Lexan polycarbonate, not Plexi or acrylic, to provide protection from any kind of circumstance that could short between those busses. It could be hinged from above so it can be flipped out of the way or simply screwed to the mounting bulkhead to ensure separation.

Take a look at any other similar buss setup aboard.


JMO

 

[Bacchus]

"First, seem like everything in my electrical path would burn up before 20,000 amp’s is reached."

From what I have read and understand C lectric's description above is exactly what the fuse being discussed is for. It has nothing to do with loads or protecting connected loads or wires. It protects the battys & boat from a catastrophic short. I dont know what ABYC says about location but this is one case where it needs to be close to the battys... the closer the better.
The time for the current to climb in a dead short situation is fast so the fuse needs to open the circuit fast any not melt leaving a conducting path.
From your photo its hard to tell how far from the battys those buss bars and fuses are but the batty bank protection needs to be as close to the battys as possible vs where it is nice & neat to mount.

 

[The Brockerts]

There is(or was) a Lexan polycarbonate covering before the picture. Given that it was broken and only a small section remained I remove the partial covering for the picture and have a new full sheet covering the entire panel. Since it was broken it probably protect the panel from some kind of hit.
I like the idea of hinges since the original was screwed on with old fashion slot screws.

The distance from battery bank to panel is about 3 feet. Cut off switches are just above the panel.



The Brockerts

 

[C lectric]

Use the battery post square fuses made by Bussman , sold often by Blue Seas now. They are rated for 10,000A interrupt. On each battery instead of the whole bank they should do well in case of a problem.

https://www.google.com/search?q=Blu...j0i22i30l3.8427j0j15&sourceid=chrome&ie=UTF-8

They mount right on the post with an adapter.. I did this with my 3 house gel cells. Each battery has its own fuse and then the cable, 4awg runs to the buss bar. Now the cable itself is protected from a short downstream.
The fuses are available in up to a 300A rating. I used a 100A for each.
I don't need that so am thinking???? about going somewhat smaller.

A total cover for the entire set of busses will be good but I would still sort out a separator barrier between the neg. and the two positive busses. If no barrier is present it is still possible to bridge between the + & - when you are working on then no matter how carefull you are.

I prefer the polycarbonate because it is far tougher and stronger and likely would not have broken. In many other uses the Plexi is preferred but not here. Use washers under the screw heads and snug them only, do not crank and drill the holes oversize.

If the old cover was badly broken then I do not think it was made of polycarbonate [Lexan]. Rather it was made of acrylic [Plexi].

 

[Marco Flamingo]

I've been doing fuse research and came across the new ABYC fusing requirements (which don't really apply to me because of two 260A banks). But I was unfamiliar with the difference between ANL and "T" fuses. I have both on my batteries. It appears that when the prior owner moved the batteries from the engine room to the lazarette, he simply added cable and ANL fuses (250A each bank) and kept the original 250A "T" fuses. Other than possibly causing some confusion about "which fuse blew", I don't know if there is any reason not to have two fuses on a circuit. Biggest problem might be having spare T fuses onboard.

A couple things I learned. Fuse types generally have different tolerances even when rated at the same amperage, and not just fast and slow blow. I was surprised by the complexity of how different fuse types respond. Also, ANL fuses are not considered ignition protected. For that you need T fuses.

 

[Flatswing]

Problem1: Your 3208 starters can easily draw 500+A if run continuously such as when fuel priming. Cable overcurrent protection during cranking needs to exceed this which is easy on small diesels but difficult & expensive on larger ones like your 3208’s & my JD6068’s. Start cables are still one of the exclusions for OCP per ABYC because of this. Steve’s article describes paralleling the start cables (no fuse) and all other loads (class T) from most battery banks for this reason.
The high 20k AIC rating of a Type T fuse ensures that, if it blows due to exceeding it’s nominal overcurrent rating, (typically 125A-400A) the fuse doesn’t arc if it was a catastrophic short connecting to a large battery bank.

 

[DennisB1]

I recently installed a new starter in my cat 3208’s. Info with the starter suggested typically current draw would be in the area y
of 1000 amps. Peak would be 1400 amps if you could maintain 12 volts delivered voltage while cranking the engine.