Is this a decent DC setup?

Thinking in terms of lots of anchor time does this look pretty good?
42 GB, twin Lehmans, if it matters.

GENERATOR
8.5 KW Onan
5 KW Engine driven alternator

BATTERIES
House bank 12 X 6V Golf cart
Engine start 12V - D8
Gen. start 12V - HD Truck batt.

ELECTRICAL
Inverter/charger 2500A Trace

BATTERY CHARGER
Xantrex TC 40+ 110V
Is this outdated?

"House bank 12 X 6V Golf cart"

Although a lot of beer might be needed to move them , using larger batts , rather than a dozen would be more efficient.

No more than 4 batts to a string works best if you keep with golf carts.

A single Ser: 31 will start a Ford in cold weather , lots lighter than an 8D.

Look at Surette for some batts made up of 2V cells bolted together.

This will eat the output of a DN-50) bus alternator 250-300A in 12v or 24V

The inverter needs to be of the boost style that can add current to a weak dock or noisemaker output.

That would allow a smaller noisemaker , that could be run closer to full load more of the time..


And first item to purchase would be a SOC , state of charge meter, so you know where the batt set is in terms of charge percentage at all times.

There are many other brands ,,,but these are good for the House set..

For Start batts , Sears or any chain store is fine as they are easy to kill, and a guarentee swop might be required.

1. Rolls Surrette Batteries
   
   www.dcbattery.com/rolls.htmlCached
   
   Rolls Surrette batteries stocking warehouse distributor for wholesale domestic and export batteries in Miami, FL. Free quotes and fast Rolls Surrette batteries shipping.

You could stay on the hook for as long as you have fuel! Looks good to me. The only thing I would check would be the age of the batteries and have your surveyor verify everything works.

Alaskan Sea-Duction said:

You could stay on the hook for as long as you have fuel! Looks good to me. The only thing I would check would be the age of the batteries and have your surveyor verify everything works.

Click to expand...

They say "3 days on the hook without running Gennie" and if true, converting lighting to led should add more time, right?

You have the basics of a good system. I assume that the 5kw alternator is AC. That will easily run the inverter/charger (100 amps?) and the 40 amp charger while underway.

I would add the following to make it better:

1. An ACR or battery combiner to automatically tie the house and starting batteries together for simultaneous charging.

2. A battery monitor such as a Xantrex, Mastervolt, etc to keep an eye on things.

David

Lots o' house batts. I'd guess that's around 1320 Ah or so at 12V? If the inverter/charger is on that bank, seems sufficient...


The engine start batteries probably don't need to be that big. A single G31 with decent CCA rating for each engine oughta work for each. Wouldn't switch for not other reason, just thinking ahead to eventual replacement. And weight (your back).


Ditto then genset starter; a G34 should work fine.


A parallel switch on start batteries is sometimes useful. But I think I'd assume the genset will power the Xantrex charger (40 amps?) and that it would be sufficient. Wouldn't change that charger until it craps out, either... outdated or not.


Assuming wet batteries, a watering system would probably be useful.


-Chris

Our 8 KW Onan had a 4D start battery. When it died I installed a sealed no maintenance Group 24. Starts right up for 2 years now. Its a true throwaway battery.

Howard

Have you calculated what all the loads are and what your usage of said loads will be?

That Trace is getting on in years, and is a modified sinewave unit, FYI.

I agree there is no need for a 4 or 8 D battery to start a Genset. In fact you don't need an 8D to start a Lehman.

I also agree you should consider replacing the Trace with something newer like a Magnum.

Assuming the is a new to you boat I agree smaller batts for engine and genny start should be fine but unless the current stuff needs changing why spend the money now?. Try it and keep track of battery condition each day and see how it fits your life style.

bayview said:

Assuming the is a new to you boat I agree smaller batts for engine and genny start should be fine but unless the current stuff needs changing why spend the money now?. Try it and keep track of battery condition each day and see how it fits your life style.

Click to expand...

Thanks.
That's where I was going with this.
Adequate for now or as David put it "the basics of a good system."
The input here will be catalogued and refereed to whether it's this boat or another. I also thought the 8D start was over kill and excessive weight but if it all works, gradual replacement will do.

Now, why would you want a drill press in the engine room of a 42 GB?

LED are good, they are fine and will save you many many amps......

We all have different opinions. My thoughts, and I use something similar is to get rid of the engine start batteries. The 12 six volt and an isolated genset start battery are sufficient. With that large of a bank consider figuring out how to charge the house bank using both your inverter/charger and the separate charger. One way to do that is to be able to split the bank while charging and have the genset alternator and your separate charger feeding one half the bank and then the inverter/charger feeding the other half.

Hawgwash said:

5 KW Engine driven alternator

Click to expand...

That doesn't seem right.

Hawgwash said:

Now, why would you want a drill press in the engine room of a 42 GB?

Click to expand...

Capt.Bill11 said:

Click to expand...

Ok, I'll bite.

As stated these are the basics of a decent system. I would try things for a year and see how it works out before changing anything much. Just because a new inverter/charger and new batteries can easily exceed 5 boat units.

The Rolls batteries are excellent but bring your cheque book! I talked to a fellow who went 16 years on his big 2 volt cells. He also had a huge alternator. I also talked to another fellow who pooched his rolls batteries after one year because of poor battery management. He thought that his alternator was all he needed to keep his batteries properly charged and they eventually failed. His alternator was insufficient for his setup.

When it comes time to a new inverter charger, I'm very pleased with the Magnum MS2812 which is a pure sine wave inverter. The Magnum remote monitor that is an easy integration comes with an SOC meter. While it's nice to augment a low shore power setup at times (for example the magnum Hybrid systems), it's a rare need, in my opinion.

WRT the claims of staying on the hook for 3 days without charging...that's bad battery management IMNSHO. Best to not let the batteries go down too low before charging. My electrician recommended cycling between 70-90%.


Jim
Sent from my iPad using Trawler Forum

JDCAVE said:

WRT the claims of staying on the hook for 3 days without charging...that's bad battery management IMNSHO. Best to not let the batteries go down too low before charging. My electrician recommended cycling between 70-90%.

Click to expand...

I guess it all depends on their usage during those 3 days. He did say it "was possible" but not something they made a habit of.

As for depth of discharge, I always thought 50% was not detrimental as long as a good 100% recharge (ie shore power) was carried out once every couple of weeks or so.

More learning to do I guess.
Thanks Jim.

I have separate fridge and freezer units. When it's hot out we can easily use 250 amp hours or 22% of house bank capacity, SOC 78%. If you then recharge, you might her it back to 95%. The next discharge cycle brings you back down to 73% so you bring it back up to about. 90% and so on. You don't want to start a 2 week anchoring cycle going all the way down to 50% on the first go.

It's because the charge-discharge cycle trends to lower SOC's with each discharge in the cycle, it really is important to be in top of battery management...and that's why solar has great potential for battery longevity, as solar can continue to put a charge into the batteries when the charge efficiency rate is too low for efficient use of a generator.

Calder has a great explanation of the charge-discharge cycle over several days on anchor.


Jim
Sent from my iPad using Trawler Forum

If I got this right, 40 amp charger? You would have to run your genset for...15+ hours? I would reconsider that item, I have 4 golf carts and a 120 amp charger and it takes about 3 and a bit hours to get to float.

Unless you run your engine as a charger but that's getting expensive, unless you move a lot. You need a schwack (opposite of scohtch) of solar panels too.

If there is going to be a noisemaker upgrade , a pair of belts on the front to run a really powerful alt (with a good marine V regulator) will charge the house faster than any other method.

A cheap truck heavy duty unit can be 135A for under $150 or so, with external regulator wiring as std.

About 15% of the house batt capacity would be a good size to install.

Check with the donor engine mfg to see just how many HP van be taken out the front end.

Hawgwash said:

Ok, I'll bite.

Click to expand...

I was just trying to show my shock at seeing space wasted in the engine area with a drill press.

As you seem to be alluding to, why bother. I mean how often do you need a drill press on a pleasure boat?

JDCAVE said:

WRT the claims of staying on the hook for 3 days without charging...that's bad battery management IMNSHO. Best to not let the batteries go down too low before charging. My electrician recommended cycling between 70-90%.

Click to expand...

Hawgwash said:

I guess it all depends on their usage during those 3 days. He did say it "was possible" but not something they made a habit of.

As for depth of discharge, I always thought 50% was not detrimental as long as a good 100% recharge (ie shore power) was carried out once every couple of weeks or so.

Click to expand...

Jim may have meant that his electrician recommended keeping his draw to between 70-90% state of charge (SOC). IOW, not to 70-90% depth of discharge (DoD). Staying between 70-90% SOC would be is compatible with the rule of thumb about not drawing down below 50%.

I suspect you're right about that "possible" -- but would depend on whatever installed loads and management thereof. Especially loads that might not be turned on or off just on a whim, like cabin lighting. Fridges come to mind...

Still, with genset on board... lots o' house bank... gradual improvement eventually possible as you identify specific opportunities... seems like a good prospect assuming you like it and the rest of the boat and the engines survey well.

-Chris

ranger42c said:

Jim may have meant that his electrician recommended keeping his draw to between 70-90% state of charge (SOC). IOW, not to 70-90% depth of discharge (DoD). Staying between 70-90% SOC would be is compatible with the rule of thumb about not drawing down below 50%.
-Chris

Click to expand...

Yes. 70-90% SOC. My Genny is only 4.1 KW. When I run it, the charger running at close to 125 amps is the only load for the first half hour or so. Then I turn on the water heater to keep the loads up. Depending on what we are doing, the genny may run for 1.5 hrs or so. So the charger usually moves to absorb charge before it's shut down and sometimes that's 95% SOC. On our 10 week trip this past summer I had to disable the engine heat function as the Webasto crapped out in me. So all hot water came from either the generator or shore power.


Jim
Sent from my iPad using Trawler Forum

Xsbank said:

If I got this right, 40 amp charger? You would have to run your genset for...15+ hours?

Click to expand...

I guess I should ask how old the various batteries are but here is what he said about use...
The house bank is so big that you can sit for 3 days without starting the generator. You make your own water, have smart a charging systems and huge freezer capacity. She is totally equipped - heat, water, AC, freezers - with everything running you only need a short run on the main engines or 3 hours a day on the gen. to keep batteries up to max. Or sit for 2-3 days on the hook on batteries alone if you don't want to hear the gen.

Part of the reason for asking in the first place is, this is the second GB I've seen with a 1 ton flatdeck load of batteries down there and am wondering if they are outdated ('90s) systems.

MYTraveler said:

That doesn't seem right.

Click to expand...

How so?

Capt.Bill11 said:

I was just trying to show my shock at seeing space wasted in the engine area with a drill press.
As you seem to be alluding to, why bother. I mean how often do you need a drill press on a pleasure boat?

Click to expand...

Yeah, rather have a still down there.
I thought that's what you meant but wanted to be sure you hadn't spotted something else in the picture, I missed.

I agree with many here,

Charger to small for the house set, will take forever to charge running gen-set, go up to 100amp charger better would be an inverter/charger if you can swing it.

No need for an 8D to start the mains I use a 1000 amp starter batt. size 29

Toss 2-4 180 watt solar cells on her and during daylight add back what the fridge uses at night and depending on other uses never need to run gen-set (Southern Latitudes of course)

House bank may be too large to keep happy (>75% charge) consider smaller, do a load calculation.

As it sits, charging up 12 golf-carts is going to take a LOT of generator running . What am I missing? Lots of battery capacity is great if you have the ability to charge them up again. Running a main engine at anchor is a poor way to do it.

A truck alternator is about $250+ in Vancouver in Loonies. The regulator is more. That is still a good solution but remember the rule of thumb is 10% of your battery bank capacity is the largest size of charger you should use. With 12 batteries in good shape and no solar, that means you need about 240 amps charging capacity. You have 40, adding a 135 amp alternator (they don't usually put out total rated amps) gives you about 175 amps. That is still about 9 hours of genset or about 40 litres of fuel to charge that bank plus a sh*tload of noise.

Even if you can provide 240 amps of charging power it will take 5 or 6 hours to charge that bank from 50% or so. And, all this ignores the start batteries or any others you may wish to float.

SCOTTEDAVIS said:

I agree with many here,

Charger to small for the house set, will take forever to charge running gen-set, go up to 100amp charger better would be an inverter/charger if you can swing it...

Click to expand...

Yes, but I think that "Trace" Inverter/charger must have some capacity to charge the house batteries...anyone know for sure? I'll bet it's at least 100 amps or so, on top of the 40 amp charger.


Jim
Sent from my iPad using Trawler Forum