Connect Batteries or Not on Hunter 30-2

[ChrisHunter]

I need to replace my 2 batteries on my Hunter30-2. Right now, the previous owner had them connected so I never thought about it.

When I replace my batteries, should I connect them or keep them separate. The boat does have a battery charger wired for 3 batteries. The boat is on a fresh water lake, so no long term trips.

Thanks

 

[jssailem]

Reasonable question. Has the way the boat was connected by the previous owner been serving your boat needs?
If yes then put new batteries in like the old ones. If it ain’t broke don’t try to fix it.

If you want something different the please explain what and why.

 

[Tally Ho]

One thought is that wiring 2 batteries in parallel provides one larger battery, and hence less discharge on either one.

Another thought is that having 2 batteries wired on separate switch positions, gives some redundancy should one battery get run down or have some sort of internal short.

You don’t mention if you have a separate starting battery either…something we need to know to answer more completely.

For me, I went through several iterations with my batteries…

* Lead acid - 2) 100Ah batteries, on separate switch positions. Then went to
* 6-volt golf-cart batteries. These needed to be wired in series to get 12-volts. On one switch positions and no starter battery.
* Still used the 6-volt golf cart batteries in series, then added a 12-volt battery as a backup starter battery (on B switch terminal).
* Moved to Lithium Iron Phosphate batteries…kept the 12-volt lead acid battery, now wired to the starter with a separate cut-off switch…and 2) 100Ah LFP batteries wired in parallel.
* This coming season, I have a single 314Ah LFZp battery to replace the 2) 100Ah batteries. No paralleling issue to deal with hopefully. And I retained the 12-volt lead acid battery for starting the engine.

Greg

 

[dLj]

I need to replace my 2 batteries on my Hunter30-2. Right now, the previous owner had them connected so I never thought about it.

When I replace my batteries, should I connect them or keep them separate. The boat does have a battery charger wired for 3 batteries. The boat is on a fresh water lake, so no long term trips.

Thanks

You haven't said how the 2 batteries are currently installed, what kind/size of batteries they are, or what you want to do. More information please.

dj

 

[ChrisHunter]

There are current 2 Group 27 batteries. There is no single starting battery.

They are tied together, but also tied to different battery circuits. Right now, the battery circuit is set to Battery 1.

Both are also tied to different lines of a single battery charger.

Thinking the redundancy is not required.

 

[jssailem]

Thinking the redundancy is not required.

That is generally a good thought. Setting up the system with 2 batteries is basic.
If you read the material from Rod (@Maine Sail ), he encourages boat owners to use a 2-battery bank with a single shore-powered and a single alternator-powered charge system. It is simple, straightforward, and can provide years of service.
Here is a link to the simple to complex approaches from MaineSail's website:
/mainesail

We vary from this simple infrastructure by creating backup systems that enhance our usability while providing alternate methods should our basic system fail.

With two group 27 batteries, you can make it in One Bank, and it will do all you need. Simple. Just monitor your battery charge consumption so that you can still start your auxiliary engine if needed.

1. They are tied together,
2. but also tied to different battery circuits.
3. Right now, the battery circuit is set to Battery 1
4. Both are also tied to different lines of a single battery charger.

Can you clarify? Perhaps draw out the connections/circuits on paper or post images of the battery.

When you say #1
I assume that the batteries are connected in parallel, providing 12V power to your boat circuits. I assume this because it is logical. The batteries might also be connected in series. This produces 24 power. Not likely, but since electrical connections are sometimes done poorly , verification is essential. It is a safety issue.

#4. It is also a safety issue. How are they "tied to different lines of a single Battery"?

 

[Tally Ho]

That is generally a good thought. Setting up the system with 2 batteries is basic.
If you read the material from Rod (@Maine Sail ), he encourages boat owners to use a 2-battery bank with a single shore-powered and a single alternator-powered charge system. It is simple, straightforward, and can provide years of service.
Here is a link to the simple to complex approaches from MaineSail's website:
/mainesail

We vary from this simple infrastructure by creating backup systems that enhance our usability while providing alternate methods should our basic system fail.

With two group 27 batteries, you can make it in One Bank, and it will do all you need. Simple. Just monitor your battery charge consumption so that you can still start your auxiliary engine if needed.


Can you clarify? Perhaps draw out the connections/circuits on paper or post images of the battery.

When you say #1
I assume that the batteries are connected in parallel, providing 12V power to your boat circuits. I assume this because it is logical. The batteries might also be connected in series. This produces 24 power. Not likely, but since electrical connections are sometimes done poorly , verification is essential. It is a safety issue.

#4. It is also a safety issue. How are they "tied to different lines of a single Battery"?

I would read #4 as each battery wired to separate charger outputs. My Guest charger has 2 charging outputs.

Hopefully the OP confirms.


Greg

 

[jssailem]

I did not want to guess. Too many unknowns.

 

[ChrisHunter]

It will be a week before I get up to my boat. Will confirm connections when I can check.

 

[Terry Cox]

An H28 was our first boat with two group 27 lead acid batteries. Each battery was wired separately to the battery selection switch. That way we would always alternate between each in order to balance use plus avoid running put of starting power. So, each time we left for a cruise, we would use one battery to start the engine and for boat consumption. The next time out we would use the other battery for starting and consumption. This technique helped to ensure we had enough power to start the engine.