Please help with DC wiring

Maine Sail

Maine Sail

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Feb 6, 1998
11,759
Canadian Sailcraft 36T Casco Bay, ME
Jeunesse27 said:
Ok so more on AGM and xantrex... I wonder why does xantrex specify a minimum of 80ah banks per output charge post on a 40A charger???
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Legal department..

Jeunesse27 said:
My D34M battery can easily take 55A (1C) charge rate so it seems that me trying to satisfy xantrex specs by purchasing 2 D34M (55ah) batteries only works against me?! I should have had bought the 60A charger and only hooked up a single battery to it to take advantage of the AGM's fast recharge, as a matter of fact I could buy 2 60A chargers and wire them in parallel to charge my AGM's which is why I think they came out with the paralleling feature on the new TC2 models... I'm starting to get a really sour taste in my mouth from all the sales pitch BS from various stores and that includes Xantrex tech support...
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With large AGM banks folks usually move to an inverter charger where it is easy to find larger current chargers.
 
Jeunesse27

Jeunesse27

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May 13, 2011
86
Catalina 30 Vancouver, BC
Ok, so I stayed up till 2am reading up on suggested links...

Here's my conclusion on the best way of setting up my battery needs.

I already have 2 brand new optima blue top batteries that are 55ah each, I should wire those as my dedicated start/reserve bank. I would then get two lifeline GPL-27T (100ah ea) batteries for my house bank which I would charger with my TC2/40 for the time being and eventually parallel in a second one to get my charge amperage up to 80A. Directing charging power from my alternator to the house bank would be pointless unless my alternator is indeed a 90 or 100 amp, otherwise I should just feed that to the reserve/start bank to keep those batteries happy and always topped up and to keep the start/reserve bank topped up while on shore power I could get an echo charger with the house bank as the source. I rarely go for trips that are 2 days away from shore power and I'd say 99% of the time I'm on shore power every night when I go cruising. Any comments on that second diagram I posted?
 
Stu Jackson

Stu Jackson

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Feb 26, 2004
23,352
Catalina 34 224 Maple Bay, BC, Canada
You seem to be heading in the right direction, but after reading all those links you still got it backwards.

The reserve/start bank does NOT need much "topping off" if any. It is the HOUSE bank that is used more extensively.

Run the AO regardless of the size of your alternator to the house bank, and use the EC for the reserve. Why? Cuz the EC is current limited, so you want the charge to go to the more used house bank.

Having to retype this stuff...:)
 
Jeunesse27

Jeunesse27

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May 13, 2011
86
Catalina 30 Vancouver, BC
Stu Jackson said:
You seem to be heading in the right direction, but after reading all those links you still got it backwards.

The reserve/start bank does NOT need much "topping off" if any. It is the HOUSE bank that is used more extensively.

Run the AO regardless of the size of your alternator to the house bank, and use the EC for the reserve. Why? Cuz the EC is current limited, so you want the charge to go to the more used house bank.

Having to retype this stuff...:)
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Yes I hear ya, but as MS stated charging AGM batteries at lower C rating actually damages them (unless I misunderstood). So because my start/reserve battery bank is smaller (110ah) the available AO is more suited to that bank. As an example without knowing for sure my AO output but assuming it's 50A, if I feed that to my start/reserve bank of 110ah I would be charging at .45C now if I fed the AO to my house bank of 200ah I would only be charging at .25C. This is a very simplistic calculation which obviously doesn't account for inefficiencies and rising temperatures which lower output during charge, but that proves my point even further as the charge rate would drop even lower.
 
G

gettinthere

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Nov 26, 2008
1,970
Endeavour 42 Cruisin
Does anyone have examples of people dying from battery gasses from wet cell batteries? Our 80's vintage production boat was built with the batteries under the aft cabin bunk. Thousands and thousands of boats (maybe millions) have wet cell batteries in or vented to living spaces. I don't recall hundreds of deaths attributed to battery gassing.

Set up properly, they ARE safe and much more reliable and cost effective.
 
Stu Jackson

Stu Jackson

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Feb 26, 2004
23,352
Catalina 34 224 Maple Bay, BC, Canada
I hear you, except the reserve bank is going to be "almost & completely" full even if you started your engine eight times without recharging. 0.2 to 0.5 ah.

So the issue of charge levels is meaningless. It's the battery acceptance that will determine what's happening. The batteries will only take what they can absorb.

Please, you seem to be trying to reinvent the wheel. And maybe overthinking this quite a bit.

Good luck.
 
Jeunesse27

Jeunesse27

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May 13, 2011
86
Catalina 30 Vancouver, BC
gettinthere said:
Does anyone have examples of people dying from battery gasses from wet cell batteries? Our 80's vintage production boat was built with the batteries under the aft cabin bunk. Thousands and thousands of boats (maybe millions) have wet cell batteries in or vented to living spaces. I don't recall hundreds of deaths attributed to battery gassing.

Set up properly, they ARE safe and much more reliable and cost effective.
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I understand what you are saying and most likely statistics will prove that, although as a personal choice I prefer sealed batteries.
 
Jeunesse27

Jeunesse27

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May 13, 2011
86
Catalina 30 Vancouver, BC
Stu Jackson said:
I hear you, except the reserve bank is going to be "almost & completely" full even if you started your engine eight times without recharging. 0.2 to 0.5 ah.

So the issue of charge levels is meaningless. It's the battery acceptance that will determine what's happening. The batteries will only take what they can absorb.

Please, you seem to be trying to reinvent the wheel. And maybe overthinking this quite a bit.

Good luck.
Click to expand
I don't think I'm trying to re-invent the wheel or overthink it. I read what MS had to say about AGM batteries and now am trying to come up with the best charging solution to ensure long life of my AGMs. Having said that the suggestion you make is to direct AO to house banks and use an echo charger to keep start/reserve bank at 100%, correct?
 
S

Solstice

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May 10, 2008
392
Catalina 355 Boston
Jeunesse27 said:
I don't think I'm trying to re-invent the wheel or overthink it. I read what MS had to say about AGM batteries and now am trying to come up with the best charging solution to ensure long life of my AGMs. Having said that the suggestion you make is to direct AO to house banks and use an echo charger to keep start/reserve bank at 100%, correct?
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FWIW, I've set my charging system up the way Stu and MS have described. My last boat consisted of a House Bank of 2 4D AGMs and a Grp 27 Reserve (starting) using a Yandina Combiner. I had a 50A alt and a 30A charger. The AGMs were 8 years old when I sold the boat and still going strong.
My new boat came with wet cells for House and I added an AGM for a Reserve. Instead of a combiner I went with an EC. So all charging sources go to the House and the EC tops up the Reserve. When these batteries die, I haven't decided whether to stick with Wet or back to AGMs. I can't do 6V due to height restrictions. I think MS overall point with AGMs is that they need to be charged properly. I consulted with him for my current setup. I have a 40A charger and a 60A Alt currently. When I get a chance I will post my wiring diagram for you if you would like...
 
Jeunesse27

Jeunesse27

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May 13, 2011
86
Catalina 30 Vancouver, BC
Solstice said:
FWIW, I've set my charging system up the way Stu and MS have described. My last boat consisted of a House Bank of 2 4D AGMs and a Grp 27 Reserve (starting) using a Yandina Combiner. I had a 50A alt and a 30A charger. The AGMs were 8 years old when I sold the boat and still going strong.
My new boat came with wet cells for House and I added an AGM for a Reserve. Instead of a combiner I went with an EC. So all charging sources go to the House and the EC tops up the Reserve. When these batteries die, I haven't decided whether to stick with Wet or back to AGMs. I can't do 6V due to height restrictions. I think MS overall point with AGMs is that they need to be charged properly. I consulted with him for my current setup. I have a 40A charger and a 60A Alt currently. When I get a chance I will post my wiring diagram for you if you would like...
Click to expand
That sounds pretty much like what I'm leaning towards in terms of wiring it. I'm just at my computer right now playing around with TurboCAD trying to create a wiring diagram.
 
S

Solstice

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May 10, 2008
392
Catalina 355 Boston
Jeunesse27 said:
That sounds pretty much like what I'm leaning towards in terms of wiring it. I'm just at my computer right now playing around with TurboCAD trying to create a wiring diagram.
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Hope this helps. I have all kinds of engineering related SW, but went with a quick and dirty Powerpoint to draw this up...
 

Attachments

Stu Jackson

Stu Jackson

.
Feb 26, 2004
23,352
Catalina 34 224 Maple Bay, BC, Canada
Jeunesse27 said:
...the suggestion you make is to direct AO to house banks and use an echo charger to keep start/reserve bank at 100%, correct?
Click to expand
Yes. And as Solstice said, and MS provided, AGMs last longest when kept fully charged.

AGM Battery Issues (from Maine Sail)
http://forums.sbo.sailboatowners.com/showthread.php?t=124973

AGM Battery Issues and the Blue Seas Dual Circuit Switch (from Maine Sail) "DARN AGM Batteries"
http://forums.catalina.sailboatowners.com/showthread.php?p=848465&highlight=darn agm
 
Jeunesse27

Jeunesse27

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May 13, 2011
86
Catalina 30 Vancouver, BC
In terms of calculating my real life house bank size needs what do you all recommend for keep track of used ah? Xantrex LinkLite? I see the MasterVolt BTM-III gets really good reviews but it's double the price...
 
S

Solstice

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May 10, 2008
392
Catalina 355 Boston
Jeunesse27 said:
In terms of calculating my real life house bank size needs what do you all recommend for keep track of used ah? Xantrex LinkLite? I see the MasterVolt BTM-III gets really good reviews but it's double the price...
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Victron single Battery Monitor. Another MS recommendation that I am very happy with. Had a Link on my last boat, but the plug and play of the Victron is great....
 
Jeunesse27

Jeunesse27

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May 13, 2011
86
Catalina 30 Vancouver, BC
So here's my day's work, well since noon anyway... There might be some mistakes there so if you see any please point them out so I can modify my diagram. Thanks everyone for helping out!
 

Attachments

Maine Sail

Maine Sail

.
Feb 6, 1998
11,759
Canadian Sailcraft 36T Casco Bay, ME
Jeunesse27 said:
So here's my day's work, well since noon anyway... There might be some mistakes there so if you see any please point them out so I can modify my diagram. Thanks everyone for helping out!
Click to expand
Starter & OB should come off "C" post of batt switch. As is now you have no isolation of start battery from starter or outboard.. If one of those starters should hang up yoo'd be glad you had a switch. Also a requirement if you want to wire to safety standards. Don't forget over current protection for batteries..I also don't see wire gauges?

P.S. I just finished a few months of testing the new Balmar Smart Gauge and hands down it is the most simple battery capacity meter out there. Battery monitors are great but only as great as how you use, program them and track changes in your batteries... The Smart Gauge is truly plug and play....
 
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