M-25 Electrical

[rbmcintire]

New C-30 owner, "long-time listener, first-time caller". I've read several of the threads on configuring the DC power wiring, and their advantages over the OEM set-up have inspired me to implement those ideas. I have an existing POS connection from my 51 amp alternator going to my starter (a 10 gauge wire!) which then runs back to the Perko battery switch and lands on the Common terminal. I think I'm pretty clear on running the alternator to the house bank and the starter to the Common of the battery switch, but what I want to know is: do I permanently remove this connection between the two and are there some basic issues to be concerned about in doing this, in relation to voltage regulation, starting or engine panel gauges? First, let me say thank you to all of you for getting me to this point of even being able to ask such a question.

Rob

 

[Stu Jackson]

...what I want to know is: do I permanently remove this connection between the two and are there some basic issues to be concerned about in doing this, in relation to voltage regulation, starting or engine panel gauges?

Rob,

Glad you got this far!

The answer is yes to the first question: remove that connection.

The reason is that this small wire was the only connection to the starter solenoid from the alternator output + post that went back to the C post of the switch. That would be the single #4 wire that reversed current: when statrting power went from battery to switch thru wire to alternator output + post thru the small wire to the starter solenoid. Once the engine started, that wire had no current flowing since the start button was disengaged and the alternator started output flowing back(wards) thru the same #4 wire from the alternator to the C post of the switch and then on to the batteries.

Cover in reply #11, here: http://c34.org/bbs/index.php/topic,4949.0.html

The answer is no effect to the second question. Answers the same question in more detail. No impact on charging (what you have now is better and simpler), or gauges, or starting, assuming you moved the #4 wire from the C post of the switch from the alternator to the starter solenoid. Regulation is done from the regulator, whether internal or external and the battery bank.

 

[Bob S]

What an asset it is to have you here Stu.
Thank you again!

 

[rbmcintire]

Thanks Stu. I'm still in the planning stages, but the goal is to improve the existing configuration. I just bought the boat in Feb. and have decided that an electrical upgrade is a priority. It has two banks of 2 batteries (under nav station and under the aft berth), two separate battery chargers, no inverter and some less than ideal NEG ground connections. In general, the idea is to combine all four into a House bank and add a new cranking Reserve battery next to the two under the aft berth.

Rob

 

[Team118]

Bob S is right. The minute I saw the electical topic, I knew Stu would respond and make it sound easy.

While Stu didn't do the wood work, that panel and everything behind it is directly because of him!

Good luck Rob, I bet you can't wait...

 

[Stephen K]

.... It has two banks of 2 batteries (under nav station and under the aft berth), two separate battery chargers, no inverter and some less than ideal NEG ground connections. In general, the idea is to combine all four into a House bank and add a new cranking Reserve battery next to the two under the aft berth.

Rob

Hi Rob,

I don't know your DC electrical consumption and how long you plan on being away from shore power, but that's a lot of batteries (and AMP hours) for a 30 footer. You might consider setting up a 2 banks of 2 batteries each and skip the start battery...just a thought.

 

[rbmcintire]

More Inspiration!
Seriously, this is why I bought a C-30.

Thanks Team118

Rob

 

[rbmcintire]

Hi Rob,

I don't know your DC electrical consumption and how long you plan on being away from shore power, but that's a lot of batteries (and AMP hours) for a 30 footer. You might consider setting up a 2 banks of 2 batteries each and skip the start battery...just a thought.

I do need to have a better handle on our consumption and will work up one of the spreadsheets I've seen. Mostly, we will be daysailing or weekending out of our marina and recharging at the dock. The alternator looks to be the 1984 original. All the batteries are Group 24 wetcells with 2007 and 2008 dates. One group of two are 85A/h and the other two are 65A/h. A nominal 300A/h, but what's a real working capacity with this team of horses?

 

[Stu Jackson]

I don't know your DC electrical consumption and how long you plan on being away from shore power, but that's a lot of batteries (and AMP hours) for a 30 footer. You might consider setting up a 2 banks of 2 batteries each and skip the start battery...just a thought.

That is unfortunately a way old way of thinking, and surely is among the worst ideas for anyone with a fridge on their boat. It has absolutely nothing to do with the size of a boat.

The best thing to have is the largest house bank you can install. It reduces the % draw of any bank with the same daily load (regardless of how large or small that load may be) and thereby increases the life of the same amount of lead (i.e., batteries) significantly.

The "start" battery should be only a reserve bank, a "just in case." We have stopped calling them start batteries for good reason, because the house bank is used for everything. It is a reserve, emergency or backup. You might be interested in this link which discusses it in detail, mostly on page 2 of the thread: http://forums.catalina.sailboatowners.com/showthread.php?t=104505

And, thanks guys, much appreciated and even better, glad to help.

Save yourself some trouble working up your own energy budget, just use this: http://c34.org/bbs/index.php/topic,3976.0.html The numbers don't change much appreciably for anyone.

 

[Bad Obsession]

When you are designing batter banks for the Catalina 30 you have a space problem. The best I have been able to do is two group 27 batteries for the batter bank and a groups 24 "starting" battery as the Auxilary battery. There is no place to put batteries on the Catalina 30 past that point and fitting that in there was tight. I guess if you took out the starboard water tank you could add batteries in the boat there but that would be a bad sacrifice.

Anyone else add batteries in an interesting place?

 

[rbmcintire]

When you are designing batter banks for the Catalina 30 you have a space problem. The best I have been able to do is two group 27 batteries for the batter bank and a groups 24 "starting" battery as the Auxilary battery. There is no place to put batteries on the Catalina 30 past that point and fitting that in there was tight. I guess if you took out the starboard water tank you could add batteries in the boat there but that would be a bad sacrifice.

Anyone else add batteries in an interesting place?

Hey Bad,

Here are the two locations on my boat. Under the Nav station and under the aft berth. I think I can squeeze a third GRP24 in to the left of the two next to the diesel tank:

 

[rbmcintire]

That is unfortunately a way old way of thinking, and surely is among the worst ideas for anyone with a fridge on their boat. It has absolutely nothing to do with the size of a boat.

The best thing to have is the largest house bank you can install. It reduces the % draw of any bank with the same daily load (regardless of how large or small that load may be) and thereby increases the life of the same amount of lead (i.e., batteries) significantly.

The "start" battery should be only a reserve bank, a "just in case." We have stopped calling them start batteries for good reason, because the house bank is used for everything. It is a reserve, emergency or backup. You might be interested in this link which discusses it in detail, mostly on page 2 of the thread: http://forums.catalina.sailboatowners.com/showthread.php?t=104505

And, thanks guys, much appreciated and even better, glad to help.

Save yourself some trouble working up your own energy budget, just use this: http://c34.org/bbs/index.php/topic,3976.0.html The numbers don't change much appreciably for anyone.

Very Much Appreciated Sir. Adding an inverter and its additonal A/C loads means I will definitely need to keep an eye on the battery monitor, mostly on the overnights.

Rob

 

[Bad Obsession]

That is for an MKI. MKII has the open Nav Station and the batteries are located, from the factor, under the starboard salon setti. I added my single group 24 starter battery under the quarter berth.

 

[rbmcintire]

That is for an MKI. MKII has the open Nav Station and the batteries are located, from the factor, under the starboard salon setti. I added my single group 24 starter battery under the quarter berth.

I think you're just trying to stay in go-fast mode by keeping the weight down. First time I go up the Potomac, I'm lookin' for ya

 

[Team118]

I put 2 house batteries and the battery charger under the nav table and the reserve battery in the engine bay.

The water pump is under the house battery bank set up. I removed the original storage cover and created a duel battery box that is secured to the hull. I can reach under the batteries to get to the pump if need be or pull the batteries in an exteme overhaul is required.

Before

This was after. Since this, I created a louvered door to cover the opening. Last summer, I just left it open. I never noticed it from the cockpit!

 

[rbmcintire]

Team, I really like boxing in the spindle rail shelf above the nav station. I think I'm going to put a Freedom HF I/C and a LINK Light Battery Monitor up there, mounting the displays on the face of it. Yours is down in the cabinet, which is also great splashproof location. On my boat, one of the previous owners has mounted TWO battery chargers on the exterior of the nav (rightside, facing the aft berth), right under the companionway, which I think is too exposed. What kind of charger are you using and do you ever have a concern for overheating inside the enclosure?

Rob

 

[Team118]

Rob;

I found a XantrexTrue Charge 40amp multi stage battery charger on Ebay. I bought the remote monitor panel and the temp sensor for the house batteries.

It did a great job all summer. The charger has it's own internal fan and I never noticed an issue with heat. Since I installed a door over the front, I'm thinking of installing a PC fan on the back of the door. These fans have a low draw and run forever...

Chris