New Old Topic - Starting Batt

iSailor · Apr 8, 2012

my 310 that I just bought last fall has the original batteries plus a 12volt "starter" battery wired into bank 2.

Siamese · Apr 8, 2012

Is your current setup 2-4D batteries?

Do some searching on this site, as well as Sailnet, and see if you don't find some VERY compelling reasons to replace your 4D batteries with 6 volt golf cart batteries. Two cart batteries wired together give you 12volts, with more amp hours than a 4D, and generally are heavier duty for true deep cycling. The two 6volts have about the same footprint as a single 4D, and are just a little taller. They just need to be connected together (minus to plus) with a cable you can order from genuinedealz.com.

Another advantage to the cart battery is you'll never have to lift a 4D again. Carrying a cart battery is like carrying a group 27.

Sam's club is a great source for cart batts.....about $72 each. If you measure your battery compartment, and there's enough room, this would make sense.

Definitely nice to have a separate starting battery. One alternative is to use the cart battery for EVERYTHING, and have the starting battery ready and charged just for emergencies. Starting off the cart battery bank will not harm them.

My 309 had a different setup than your 310. One 4D and one group 27 for starting. I just replaced the single 4D with a pair of cart batteries. I replaced my group 27 with a group 24 to be used strictly as my emergency start battery. Spins my 3ym20 Yanmar just fine.

truckman · Apr 8, 2012

Russ, I added a starting battery and wired my still good 4D's together to give me a dedicated house bank on the switch bank #1 and my starter/emergency battery was bank #2. I don't bother using the emergency/starter battery often for starting and it is kept charged via the shore power trickle charger. This configuration has served me well and gives me way more amp hours than I usually need even on long trips of 2 weeks. If my 4D's were in need of replacement I would definitely go with the golf cart batteries and a separate emergency/starter. If you search this site you will find lots of posts.

darrenwb · Apr 9, 2012

So I bought my 310 this winter and I can't wait to get her back in the water. During the survey I was told that 1 is house and 2 is starting, my DC service only works on Battery 1 or All. Does that sound right?

mfarinas · Apr 10, 2012

darrenwb said:
So I bought my 310 this winter and I can't wait to get her back in the water. During the survey I was told that 1 is house and 2 is starting, my DC service only works on Battery 1 or All. Does that sound right?

My 2003 C-310 is wired with the #2 switch position for the house batteries and # 1 for the starting battery. I had to replace the 4-D batteries a year ago, and simply bought two group 31 batteries connected where the 4-D's were. So far they seem to be working fine.

darrenwb · Apr 10, 2012

mfarinas said:
My 2003 C-310 is wired with the #2 switch position for the house batteries and # 1 for the starting battery. I had to replace the 4-D batteries a year ago, and simply bought two group 31 batteries connected where the 4-D's were. So far they seem to be working fine.

So can you run your DC service like lights off "starting battery"?

Tom J · Apr 10, 2012

Long Story said:
I am asking 310'ers due to our space limits and such. I am sure I have seen this posted before but I can't find it. I was even sure there was another article done on this. How have people added a dedicated starting batt? Did you keep your normal 1-2 switch? Did you go to one house bank, and the starter, or keep two house banks? Anyone switched from the 4-D batts to lighter group 31's and if so how did you set this up? Wiring digram is appreciated. My batt's need to be replaced and couple people suggested a change to the group 31 one house bank, and a separate group 27 starting batt. Let me know please how this has been done?

Thank you all

Russ

You're certainly correct that there are a number of previous posts about this topic. MaineSail is your best source of information about this upgrade. It was the first upgrade I did on my 310, and one of the most useful. I opted to parallel the 4D's and install a start battery in the port settee locker. I also installed a different battery switch, one that isolates the start circuit from the house circuit, along with an automatic charging relay. Now, when I start the engine, the start battery is charged first, and then the house batteries. When I shut down, the start battery is automatically isolated from the house batteries. Of course, this is just my preference. Some folks like to charge the house bank first, then the start battery. And a lot of folks like to keep the old 1-both-2 switch and control things manually. So you'll probably want to review those old posts and see what will work best for you.

Stu Jackson · Apr 10, 2012

Russ, good question. And yes there have been many discussions about just this topic.

You could go to the Forum tab at the top of this board, and scroll down to Featured Contributors, and Musing with Maine Sail. Scroll down and open all the threads from beginning, and read on.

This topic, from our C34 Board, has a lot of links back to some from this Board.

"It all depends on how it's wired" is a very important issue, don't know what you know or don't know about boat electrics.

http://c34.org/bbs/index.php/topic,5977.0.html

Reply #25 on page 2 of that topic has a great way to download an entire and very good boat electrical book.

mfarinas · Apr 21, 2012

darrenwb said:
So can you run your DC service like lights off "starting battery"?

Yes! All Direct Current items run no matter in what position the switch is at. Of course, NOT when in the "off" position.
My boat came equipped with an inverter which runs only the air conditioner. I think who ever wired this changed the entire configuration. I normally leave the switch on "all" for starting, and only switch it to "2" ( my house bank) when anchored. I tried using bank #1 a few weeks ago as the house battery, and it only lasted about 3 hours before running very low. Had to switch to "all" and start the engine.
If anyone out there has any ideas, please let me know. A friend with an Albin 34 has bank #1 for the house, and bank #2 for the starting. No direct current is available to the boat when using the starting bank. So this is puzzling to me why I always have direct current in the boat no matter what bank I use.
Hope this helps.
Thanks

Tom J · Apr 21, 2012

mfarinas said:
Yes! All Direct Current items run no matter in what position the switch is at. Of course, NOT when in the "off" position.
My boat came equipped with an inverter which runs only the air conditioner. I think who ever wired this changed the entire configuration. I normally leave the switch on "all" for starting, and only switch it to "2" ( my house bank) when anchored. I tried using bank #1 a few weeks ago as the house battery, and it only lasted about 3 hours before running very low. Had to switch to "all" and start the engine.
If anyone out there has any ideas, please let me know. A friend with an Albin 34 has bank #1 for the house, and bank #2 for the starting. No direct current is available to the boat when using the starting bank. So this is puzzling to me why I always have direct current in the boat no matter what bank I use.
Hope this helps.
Thanks

There are different types of battery switches. Your's is the more standard 1-2-both switch. It has a common output from the batteries, hence you get voltage to the house panel from either battery. The Albin probably has the same type I have. It is On-Off-All. It has two outputs, one to the starter and one to the house panel. Thus, in the ON position, the start battery feeds the starter, and the house battery feeds the house panel. The ALL position would combine all the inputs and outputs so that both battery banks feed the starter and house panel. Does this help?

mfarinas · Apr 21, 2012

Thanks Tom, I think this clears up the mystery.

Tom J · May 8, 2012

There is a lot of interest in this post and the subject in general. The archives are full of posts about the start battery install. The thing is, everyone has their own preferences about what they want and how to do it. This is typical of boat electrical systems in general, I think. When I worked at a marina, we required all boat owners to submit a detailed description of where their battery switches were, and what they did. If we had a problem on the boat, we had to know how to shut things down, or if the mechanic had to work on the boat, he had to know how to kill the circuits. You wouldn't believe how complicated some of those systems were. So, as has been said many times on this forum, your boat, your choice.

Stu Jackson · May 8, 2012

Long Story said:
I must need to figure out how to make a photo show up to generate some interest... in this post. I am now considering pulling the cables back to the motor and battery compartment to shorten the runs and have no alternator lead on the "C" post at the 1-2-B

What a good idea!

Try this:

Basic Battery Wiring Diagrams This is a very good basic primer for boat system wiring: http://c34.org/bbs/index.php/topic,6604.0.html

This is another very good basic primer for boat system wiring: The 1-2-B Switch by Maine Sail (brings together a lot of what this subject is all about)
http://forums.catalina.sailboatowners.com/showthread.php?t=137615

Your boat, your choice.

Maine Sail · May 9, 2012

Long Story said:
So let the ACR charge up the starter, then switch over to charge the house, which will need more charge time anyway…?

Is my thinking logical?

Russ

This is not how an ACR works. They simply "COMBINE" the banks, just like using the BOTH feature of a 1/2/BOTH switch, when either bank hits a preset turn on voltage (some models only sense one battery for voltage turn on).. When the house bank is larger than the starting bank it is much preferred to route the alternator charging to the house bank rather than the starting bank to prevent relay cycling..

New Old Topic - Starting Batt

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