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Old 03-06-2013, 17:30   #106
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Re: House Batteries in my Westsail 32

Just as a reference EotR,

You can calculate what the voltage drop should be in any given wire. You need to measure the voltage between two points and then the amperage during the voltage test and you can easily plug this into a voltage drop calculator like the one here:
Voltage Drop Calculator

If you put in your parameters...
3 ft of 4awg copper wire @ 12.62 volts DC
@ 1 amp of current you should have a voltage drop of:
Votage drop: 0.0015
Votage drop percentage: 0.012%
Votage at the end: 12.6185


Which is way less than the .07v drop you are seeing. As the amps increase the voltage drop will increase as well, but even so you'd have to be pulling some serious amps to make a 3ft 4awg gauge wire drop as much as you're reading.
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Old 03-06-2013, 17:34   #107
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Originally Posted by endoftheroad View Post
Thanks Jedi,
Thanks Target,

I didn't know it was this easy, I will replace the cable then. I will test the other sections now that I know how to do it and replace the necessary ones.
Someday I will look back at this and laugh, today I'm excited and looking forward to a sound electrical system on my boat.

So...to all you greenhorns reading this, turn on your motor, climb into your engine room and start feeling up your cable.

endoftheroad
It is a function of the current that the cable is carrying. It's the good old Ohm's law : resistance = voltage / current ( R=U/I)

An AWG4 cable is 0.24 Ohm per 1,000'. You have, say, 4' so that would be 0.24 / 1000 * 4 = 0.001 Ohm (is why I take 4', easy number). I will now rewrite the formula so that I can get the current from the calculated resistance and the measured voltage:

I=U/R = 0.07 / 0.001 = 70 Amps. Which is unbelievable. The only conclusion is that the resistance must be higher, which is caused by the crimps/terminals/corrosion. Let us assume there was 10 Amps current. Then the resistance was 0.07 / 10 = 0.007 Ohm, which is 7 times higher than the wire alone.

So, check how much current goes through, then measure the voltage across the cable. Checking the temperature is a quick way to find trouble. I use one of those IR thermometers that you can just point at something. I use it for everything: cables, terminals, injectors (all same temp?), fridge seals (cold spot is a leak!) etc.
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Old 05-06-2013, 08:58   #108
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Okay, I found another cable that was bad, I replaced both, I ran the motor and NO warm cables alas.

I have installed my Victron battery monitor sucessfully this morning.
I am ready to syncronize the display.

I need to manually insert my batt banks amp hours into the display.

My batteries are 4 Trojan T-105's 6 volts wired in series/parallel.
I'm a bit confused as to what to enter into the display.
Is it supposed to be 210 or 420 amp hours?
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Old 05-06-2013, 09:24   #109
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Re: House Batteries in my Westsail 32

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Originally Posted by IceDog View Post
Hi End of the Road,

The previous batteries were rated at 105 amp hours at 12 volts and he had 4 of them. Was that in one bank for house use with an additional battery for starting or is that the total he had?
Most battery types provide 40-50 percent of the rated amp hours because you don't want to discharge much beyond 50%. If the total battery rated amp hours=4x105 or 420ah, then realistically, you should expect 170 to 210 ah to be available from the original style battery IF all four were used as the house bank.
The Trojan T-105 6 volt battery is rated at 255 ah at 6 volts. It takes two of them in series to make 12 volts at the same ah. 4 of them would be rated at 510 ah wired in series/parallel. That would provide between 204ah and 255ah (set up as one bank) realistically available per day if you want to maximize battery life. If they are split into two banks, each pair will be wired in series and provide half the ah.
The fridge would probably be the biggest power consumer on your boat. I haven't researched fridges much yet. Caldwell has a great section on refrigeration in "Boat owner's Mechanical and Electrical manual" The quality of the fridge, door style and it's insulation along with usage patterns will help to determine the load it will represent. Did the previous owner have the fridge or is it new?
Another factor is that the wiring will need to be a little different for the 6v set and you need to check the style of terminal posts used. It may be easier to match the post style to the previous ones
Trojan T-105 6V, 225AH (20HR) Flooded Lead Acid Battery

In re-reading your post, I see it looks like he had them in two sets which may indicate that one was a starter set for the engine. If you used them as 2 hooked up as start and 2 as house battery, you could make it work but you would need to have a robust way to recharge them daily, whether that means running the engine, a genny, solar or wind. Eliminating the water maker load should help your power usage also.
In summary, 2 Trojan T-105s hooked up as a house bank will provide 102-130ah available between charges. You would have around 20% more capacity than the previous set. I have heard values for fridge use of around 60 ah but it all depends on the fridge and how you use it...
I am going to install LifeP04 batteries on my boat too DeckOfficer!



(copied from above)
The Trojan T-105 6 volt battery is rated at 255 ah at 6 volts. It takes two of them in series to make 12 volts at the same ah. 4 of them would be rated at 510 ah wired in series/parallel. That would provide between 204ah and 255ah (set up as one bank) realistically available per day if you want to maximize battery life. If they are split into two banks, each pair will be wired in series and provide half the ah.


This has always confused me.
Should I be entering 510 into my battery monitor?
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Old 05-06-2013, 09:30   #110
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Re: House Batteries in my Westsail 32

Yes. 510 amps
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Old 05-06-2013, 11:52   #111
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Re: House Batteries in my Westsail 32

Quote:
Originally Posted by endoftheroad View Post
(copied from above)
The Trojan T-105 6 volt battery is rated at 255 ah at 6 volts. It takes two of them in series to make 12 volts at the same ah. 4 of them would be rated at 510 ah wired in series/parallel. That would provide between 204ah and 255ah (set up as one bank) realistically available per day if you want to maximize battery life. If they are split into two banks, each pair will be wired in series and provide half the ah.


This has always confused me.
Should I be entering 510 into my battery monitor?
Last time I checked 4 6V T105's were 450Ah's.. 225 + 225 = 450...... The first year you will enter 450Ah...
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Old 05-06-2013, 15:06   #112
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Originally Posted by Maine Sail View Post

Last time I checked 4 6V T105's were 450Ah's.. 225 + 225 = 450...... The first year you will enter 450Ah...
I agree, they are 225Ah unless they came up with some super revision... which they did with the L16's so you never know!
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Old 05-06-2013, 17:43   #113
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Re: House Batteries in my Westsail 32

It's been over cast and rainy all day today and my Kyocera's and Genasun controllers are keeping my Trojans full and 2 ipads, 2 cell phones, 1.5 12 volt fans, fridge is cold, charged a 18 volt cordless drill battery using a 400 watt inverter.

And all I get to see on my battery monitor is SOC (state of charge) 100%.
Sure it dipped down a few times to 99% but it kept recovering.
The amps that were being put into my batteries were a slight surplus to my usage on this rainy day.

I did change my amp hours to 450 in the battery monitor display early in the day.

We even watched a dvd on a small dvd player through my jambox speaker today.

I wasted my money on the Victron battery monitor because all I get to see with my high quality setup is FULL CHARGE.


Thanks guys for all the help, super satisfied!


Jedi, I did buy the battery terminal fuse holder and 2-125 amp fuses, the bus bar, a new fuse block and a bunch of other goodies. Tomorrow or the next day I will install, then I will keep perfecting my electrical system.
Your generous time helping me install my system wasn't wasted nor taken for granted.
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Old 05-06-2013, 18:09   #114
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Re: House Batteries in my Westsail 32

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I

For two Kyocera 140's I'd be tempted to go with two Genasun GV-10 PB MPPT controllers, one for each panel and very simple.
Are the Genasun MPPT controllers adjustable as to voltage set points? I spoke to the Trojan factory and they recommended 14.7v for absorption voltage. Most controllers I have seen default to lower. The more capable brands are user-configurable. Thanks.
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Old 05-06-2013, 18:31   #115
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Re: House Batteries in my Westsail 32

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Originally Posted by F51 View Post
Are the Genasun MPPT controllers adjustable as to voltage set points? I spoke to the Trojan factory and they recommended 14.7v for absorption voltage. Most controllers I have seen default to lower. The more capable brands are user-configurable. Thanks.
They can be custom ordered for any setting you want. If you need or want a user progrmable unit Morningstar, Rogue and others make some that are reasonable and decent...
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Old 05-06-2013, 18:36   #116
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Re: House Batteries in my Westsail 32

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Originally Posted by F51 View Post
Are the Genasun MPPT controllers adjustable as to voltage set points? I spoke to the Trojan factory and they recommended 14.7v for absorption voltage. Most controllers I have seen default to lower. The more capable brands are user-configurable. Thanks.
Genasun's conservative specs state 14.4 absorption.

GV-10 | 140W 10A Solar Charge Controller with MPPT

Genasun will adjust something for a small fee but I can't remember what it is.


I have to give a work estimate tomorrow, if I can get a few minutes you'll have to dinghy over to my boat to check out my system. If not tomorrow then definately Friday.
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Old 05-06-2013, 19:16   #117
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Re: House Batteries in my Westsail 32

Just wanted to say I'm getting some good mileage out of this thread too. I have a Kyocera/Genasun/Echo charge-and-start-battery setup and I'm going to dial it in next week. I'm always trying to upgrade this stuff while sailing and well, it needs some work to make it right. Can't wait to be bobbing around at anchor and doing little wiring projects after several 90 hour weeks farming.

I've got all the terminal fuse blocks and fuses, wire, and a victron. What I don't have is bus blocks and a switch to disconnect the solar, just hadn't thought of that. EOTR, did you add a switch or just wire it from Genasuns to battery or pos bus? Whats a good affordable switch.....basic?

Now that I'm thinking along the lines of a distribution block, for tying in charging sources, 1000W inverter, house loads, etc I'm wondering how to protect it. My thought before was that each thing needs it's own protection, but if I'm really just fusing the wire from the battery to bus block, will one fuse do it, at least for loads? Could it really be that simple?

I'm still unclear how to fuse my starter and alternator, just in terms of design, and I'm trying to be a little economical with it as these fuses and spares, switches and wire are not cheap. Not that this is any place for economy, but nonetheless I want to get it right the first time and not waste money or more importantly time.... I get conflicting messages about fusing the starter, and we know how they were installed originally, but alas, I'm not one to take chances.

Should the disconnect switch for the solar panel (my only charge source besides alternator) be in between the genasun controller and the battery? ***EDIT: Just re-read and see in post #69 Maine Sail recommends in between controller and battery, and I think the controller instructions reflect that, and will double check. Current GV-10 user manual online says it doesn't matter but I remember reading otherwise in my paper copy that shipped with GV-10

Thanks for any input-
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Old 05-06-2013, 19:55   #118
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The Blue Sea Systems site has nice application notes. Here is the one for main DC distribution :

http://www.bluesea.com/support/appli...r_Distribution
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Old 05-06-2013, 20:02   #119
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Re: House Batteries in my Westsail 32

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Originally Posted by cheoah View Post
Just wanted to say I'm getting some good mileage out of this thread too. I have a Kyocera/Genasun/Echo charge-and-start-battery setup and I'm going to dial it in next week. I'm always trying to upgrade this stuff while sailing and well, it needs some work to make it right. Can't wait to be bobbing around at anchor and doing little wiring projects after several 90 hour weeks farming.

I've got all the terminal fuse blocks and fuses, wire, and a victron. What I don't have is bus blocks and a switch to disconnect the solar, just hadn't thought of that. EOTR, did you add a switch or just wire it from Genasuns to battery or pos bus? Whats a good affordable switch.....basic?

Now that I'm thinking along the lines of a distribution block, for tying in charging sources, 1000W inverter, house loads, etc I'm wondering how to protect it. My thought before was that each thing needs it's own protection, but if I'm really just fusing the wire from the battery to bus block, will one fuse do it, at least for loads? Could it really be that simple?

I'm still unclear how to fuse my starter and alternator, just in terms of design, and I'm trying to be a little economical with it as these fuses and spares, switches and wire are not cheap. Not that this is any place for economy, but nonetheless I want to get it right the first time and not waste money or more importantly time.... I get conflicting messages about fusing the starter, and we know how they were installed originally, but alas, I'm not one to take chances.

Should the disconnect switch for the solar panel (my only charge source besides alternator) be in between the genasun controller and the battery? ***EDIT: Just re-read and see in post #69 Maine Sail recommends in between controller and battery, and I think the controller instructions reflect that, and will double check. Current GV-10 user manual online says it doesn't matter but I remember reading otherwise in my paper copy that shipped with GV-10

Thanks for any input-
I think most of your answers are here in this thread.
After you start the project you will feel less overwhelmed or intimidated and you'll take off like a rocket.
Start with this terminal fuse holder (but the single version) and re-read this thread.
Your second concern may be what amp fuse (get a spare) for the fuse holder that your system requires and go from there.
BLUE SEA SYSTEMS Terminal Fuse Blocks at West Marine
I think it's a good practice to not connect any accessories or solar power directly to the batteries, use buss bars. I'm not using a switch for my solar, the inline fuse and connection to the positive buss bar is in a very accessable location.
http://www.westmarine.com/webapp/wcs...3#.UazqGsu9KSM
This bus bar is located before my switch to turn on all my boats accessories, here I connect an emergency bilge and my solar so they are always able to run should I turn off power to my boat's accessories.
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Old 05-06-2013, 22:02   #120
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Did a little more research and makes more sense to individually protect each main branch circuit. Could be really bad idea with alternator I guess to share a fuse with say a house load. I just wonder if house and inverter could share a 150a fuse?

What I really need is some time at the boat to design it but I think I now have a handle on principles. I think ill pay a marine electrician to check out my work once its all said and done. Besides branch circuits, original and added, there's no major fault protection close to battery right now.

At any rate these threads are very helpful, thanks to all who take time to contribute accurate info.
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