House Batteries in my Westsail 32

[endoftheroad]

I have had this W32 for over 1 year now and I'm finally getting to buying some house batteries. The previous owner told me he used 4 Sea Volt 105 12 volt deep cycle batteries from West Marine but took them with him when he moved to a cabin in the woods. I have been researching (searching the forum) extensively and am thinking about buying 4 Trojan 6 volt batts. It seems that the four 12 volt batts would be too heavy not to mention the hefty price tags on them.

Am I correct that I would still have about the same amp hrs as the PO's setup?

BTW, I have refrigeration, ipads, anchor light, pressure water, bilge, propane solenoid, cell phones, some lighting usage, I'm a full time liveaboard on the hook. We're pretty minimal regarding electrical consumption but the Wife is a Vegetarian and the fridge (if it works) may save my marriage .
The PO had a large modern water maker running off the previous set up that he removed.

The electrical in my boat isn't in too bad of condition, it's fairly tidy and somewhat modern.
There are 2 bays port and starboard where the batteries sat and a bunch of wires laying waiting for their new power source.

Any suggestions are appreciated.

Thanks,
endoftheroad

[deckofficer]

I'll assume the 12 volt 105's are 105 a-hr, so yes (4) 6 volt golf cart batteries in a series/parallel configuration would give you the same capacity plus 6 volt batteries have thicker plates so do better in deep cycle usage. (4) 6 volt batteries is a very common set up, I used (8) of them many years ago on my Cal 40.

Today though with the drop in prices of LiFePO4 cells, it is what I use now and don't use lead acid anymore.

[Target9000]

endoftheroad,

We installed 4 golf cart batteries on the starboard side of the engine room just behind the bulk head. I found a battery box that fit all four of them leaving the port side free for other things like the engine start battery. That gives us around 440 amp/hrs and we've been quite happy with it so far.

Lots of info on our blog if you're interested.

The spot:


Battery box


Obviously it is hard to get to them there so I installed a battery watering system:

[deckofficer]

You also could replace each cell cap with a hydrocap which converts the hydrogen back to water.

[billr]

One suggestion: when you decide what you want, check the internet prices. I bought some AGM batteries a few years ago. The boat is in northern Washington state. The best price I could find, including shipping, was from a place called Inverters R Us in Arizona.

[IceDog]

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!

[four winds]

That's the same West Marine AGM battery I have. (2) And I need new ones as well.

Last time I looked they were about $320 each at WM.

Sam's club sells Duracell (Deka) group 31 AGM 12v 105ah for $166 each.

They also have the lead acid Duracell in that 105ah capacity for $90 each. It's a group 29 but that's actually a group 31 size. (don't know why)

I'm hoping to spring for the AGMs sometime soon. But it's amazing that for the lead acid price of about $200 for 2 one gets the same capacity as WM's $600+ agm offering. Or in your case, $400 lead acid vs. $1200 AGM.


edit to add,.... I may have mistakenly thought your batteries were AGM. I have the Sea Volt brand AGMs, guessing they make lead acid also and haven't looked for the WM price for those.

[endoftheroad]

Originally Posted by four winds

That's the same West Marine AGM battery I have. (2) And I need new ones as well.

Last time I looked they were about $320 each at WM.

Sam's club sells Duracell (Deka) group 31 AGM 12v 105ah for $166 each.

They also have the lead acid Duracell in that 105ah capacity for $90 each. It's a group 29 but that's actually a group 31 size. (don't know why)

I'm hoping to spring for the AGMs sometime soon. But it's amazing that for the lead acid price of about $200 for 2 one gets the same capacity as WM's $600+ agm offering. Or in your case, $400 lead acid vs. $1200 AGM.


edit to add,.... I may have mistakenly thought your batteries were AGM. I have the Sea Volt brand AGMs, guessing they make lead acid also and haven't looked for the WM price for those.

When I bought this new boat the price for the WM batteries were about $230 (deep cycle 105ah) each, regardless of the price, the 6 volt option seems a better choice.
Even if they were the same price as 4 Trojans it still wouldn't make much sense to me to continue in the previous owners set up.

[endoftheroad]

Alot of great information here, thanks.

To Icedog;
The starter battery is seperate from these 4 batteries, I bought that new before we splashed.

To everyone;
Electrical is a new unexplored world that remains for me in sailing, I'm looking forward to discovering.

The PO said that he used the Yanmar for charging of the batteries. The Yanny has only a couple hundred hours as he recently got rid of the Westerbeke.
I don't plan on using the motor for charging for very long but I will have to until I get solar on my boat.

There is about 6-8 wires at each bank that were used on the 4-12 volt batteries.

Any pointers for what I might have to do to convert from 4-12 volters to 4-6 volters at the existing terminal ends?

I'm not asking for anyone to hold my hand as I'm aware this must be a well covered topic here on the forum. I would just like someone to come over to my boat and do it for free . Haha, just kidding.

But a few points in the right direction for me getting started would be greatly helpfull.

Thanks,
endoftheroad

[IceDog]

In order to install 4@6V batteries to provide 12V with double the capacity of one of them, you would need to install them as shown in the final drawing (series/parallel). Was the starter battery in one bay and the house batteries in the other bay or are there still two separate bays with cables laying in there? Do any of the cables go from one bay to the other or do you have a red and black running to each bay from a copper bus bar or terminal block near the alternator? Is the engine alternator the sole source of charging for the batteries at the moment?

The following excerpt is from How Lead Acid Batteries Work



Most marine, automotive, and RV applications use 12V DC. You have the choice to either buy a 12V battery or to create a 12V system by wiring several lower-voltage batteries/cells in Series.


When two 6V, 100Ah batteries are wired in Series, the voltage is doubled but the amp-hour capacity remains 100Ah (Total Power = 1200 Watt-hours).

You may decide to wire batteries in series because a single 12V battery with the right storage capacity is simply too heavy, unwieldy, or awkward to lift into place. Batteries consisting of fewer cells (and hence lower voltage) in series can provide the same storage capacity yet be portable. It is not unusual to see solar power installations where the battery bank consists of a sea of 2V batteries that have been wired in series.

Two 6V, 100Ah batteries wired in Parallel will have a total storage capacity of 200Ah at 6V (or 1200 Watt-hours).

Battery banks consisting of 12V batteries wired in parallel are often seen on OEM installations in boats and RVs alike. Such banks are simple to wire up and require a minimum of cabling. However, the wiring must have the capacity to deal with a full battery bank.

You should fuse each battery individually in such a bank to ensure that a battery gone bad will not affect the rest of the bank.

Battery banks wired in Series-Parallel are even more complicated. Here, four 6V cells are wired in two "strings" of 12VDC that were then wired in parallel. Using 6V, 100Ah batteries, this system will have a storage capacity of 200Ah at 12V or 2,400Wh.

Since such a system has more wiring, it is very important to group "strings" logically and to label everything. Furthermore, it is a very good idea to fuse every "string" of series-wired batteries to ensure that a problem in one part of the battery bank does not take the whole bank down.

[deckofficer]

IceDog, your a nice guy. For the person that fears hooking batteries in series/parallel, you just removed the mystery for them with your graphics.

[IceDog]

I started to draw some batteries using Microsoft Paint for a few minutes and then said to myself Kevin (cause that's what I call myself), just google the bloody thing. Those nice clear graphics were on the first site I looked on . I included a link to the site in my post.

[deckofficer]

Originally Posted by IceDog

I started to draw some batteries using Microsoft Paint for a few minutes and then said to myself Kevin (cause that's what I call myself), just google the bloody thing. Those nice clear graphics were on the first site I looked on . I included a link to the site in my post.

Either way, you helped the guy and that is one of the positive aspects of forums. Since you mentioned your pending upgrade to LiFePO4 cells, have you been to this mile long thread?

http://www.cruisersforum.com/forums/...nks-65069.html

[IceDog]

Deck Officer, I have read that thread in its entirety and the combined reading of that and the other LifeP04 threads on CF is what convinced me to go with that technology. I almost ordered batteries from Balqon but I won't need them until December probably so it only makes sense to wait and buy them closer to the time.

[oregonian]

Ahoy endoftheroad,
This is an alternative to your suggestion and what I have been using in my W-32 for over 30 years. Most of that time was full time living aboard and long distance voyaging. I have all the stuff on my boat as you do.
I use two group 31, AGM's only (12V). No battery box. Both batteries are used separately and equally. No distinction is made for House or Start. I have one single solar panel that is not permanently mounted and only used at anchor or when convenient. All of this is less than 1/2 of your suggestion. I (and my wife), have been discribed as more minimalist than most - but- we have never needed more capacity.
Over the years, I have used wet cell, gel cell, and AGM's. I am most happy with the AGM's. The current 2 batteries are 9 years old and are just now showing signs of needing replacement. They have travelled far and wide.
You might consider using this "smaller" capacity. It will save money, weight, and volume. If it is not enough then just add another one.
Good luck, Hope to see you down the road.