Sailboat Batteries

[RobD527]

Hello

Im new to sailing and just bought my first sailboat
Its a Hunter 33 and looks like I am needing new batteries

I have a scissor lift that has four deep cycle 6 volt batteries in it that are rarely used
Would it be smart to run them parallel to make 2 sets of 12 volt and use them or should I go shopping ?

[hobopacket]

I would go shopping. Isolate them. Two Trojan 6v golf cart is series for 12v house and then a 12v starting. Go with lead acid. Cheapest and most user friendly.

[SSgtPitt]

And date match them so they’re all the same. I did a TON of research before replacing mine and Trojans kept coming back as the best.

[RobD527]

The scissor lift batteries are 6 volt duracell golf cart from sams so I could use two of them for house. There are Four 12 volt in the boat now and I dont know whats what because there's solar, inverter and charger (wires everywhere haven't figured it out yet)

[Jon Hacking]

Rob, you haven't mentioned amp-hours or age. You say you have 4x12v now. Is one for the engine and the other 3 for the house? How many Amp-hours are they? Why do you think they need replacing? How many Ah are the golf cart batteries? Is everything flooded wet cells, or some other technology?

Deep cycle Golf cart batteries usually make excellent house batteries, but not so good at engine starting. If they're relatively new & you don't need the lift anymore, they might be a good choice. Engine batteries aren't used (cycled) as much as house batteries, so they don't need to be the same age. Is your engine start battery OK, or does it also need replacing?

Wet cells will take the most abuse, but also won't give you as many cycles, as a general rule. Gel cells have the capability to give the most cycles, but they're also the most delicate. AGMs come in between, but closer to Gels. Changing between these technologies usually means tweaking your (many) charging systems. Ideally, House and Engine batteries should be the same type, but that's not strictly necessary - it just makes things easier.

LiFePO4 batteries have the capability to give you even more cycles (lifetime) but they're even more delicate. If you're new to batteries, they're probably not a good choice, as charging profiles are quite different from lead/acid.

[newhaul]

Originally Posted by RobD527

Hello

Im new to sailing and just bought my first sailboat
Its a Hunter 33 and looks like I am needing new batteries

I have a scissor lift that has four deep cycle 6 volt batteries in it that are rarely used
Would it be smart to run them parallel to make 2 sets of 12 volt and use them or should I go shopping ?

ok I would assume that the 4 12v batteries currently on the boat are all starting batteries.
How old are the gc2's from the scissor lift?
Even if a couple years old they would make a much better house bank than the 12v batteries. I personally would look at removing 3 of the existing batteries and putting the 4 gc2 in their place as a single bank. Using one of the existing 12v batteries as a start battery. Put the rest in the garage as spares.
You say you have solar already when you get things sorted let us know what you have size and number of panels ( watt outputs) and what you have for a controller.

[roverhi]

I'd stick with lead acid Golf Cart Batteries in two separate banks. If you need the amperage or for charging, they can be combined with master switch. Do have to be careful with the 'both' position on the master switch as a bad cell could drain both banks. Of course that would be the same if they were wired in series/parallel for a single bank.

If you aren't going anywhere, would be fine to go with the GC batteries that you have. Change them out when they go bad. Would want a fresh set of batteries before leaving on an extended cruise.

[newhaul]

Originally Posted by Jon Hacking

Rob, you haven't mentioned amp-hours or age. You say you have 4x12v now. Is one for the engine and the other 3 for the house? How many Amp-hours are they? Why do you think they need replacing? How many Ah are the golf cart batteries? Is everything flooded wet cells, or some other technology?

Deep cycle Golf cart batteries usually make excellent house batteries, but not so good at engine starting. If they're relatively new & you don't need the lift anymore, they might be a good choice. Engine batteries aren't used (cycled) as much as house batteries, so they don't need to be the same age. Is your engine start battery OK, or does it also need replacing?

Wet cells will take the most abuse, but also won't give you as many cycles, as a general rule. Gel cells have the capability to give the most cycles, but they're also the most delicate. AGMs come in between, but closer to Gels. Changing between these technologies usually means tweaking your (many) charging systems. Ideally, House and Engine batteries should be the same type, but that's not strictly necessary - it just makes things easier.

LiFePO4 batteries have the capability to give you even more cycles (lifetime) but they're even more delicate. If you're new to batteries, they're probably not a good choice, as charging profiles are quite different from lead/acid.

the op is asking if he can use the gc2 batteries to replace the 12v bank and you even mentioned lifepo4

[Jon Hacking]

Originally Posted by newhaul

the op is asking if he can use the gc2 batteries to replace the 12v bank and you even mentioned lifepo4

The OP seemed to need a quick lesson in batteries.

[newhaul]

Originally Posted by Jon Hacking

The OP seemed to need a quick lesson in batteries.

Lfp isn't for the novice when it comes to batteries.

[DotDun]

There is no problem using deep cycle GC batteries for engine starting. You'll have way more starting current than required.

[Brightstar]

I’ve been stranded by one bad battery when the switch was left in the All position. I then purchased 4 golf cart batteries 2 banks, 2 6 volt in 12v, one start battery all lead acid wet batteries.
This has great capacity and starting capabilities cost me 530 total at Napa. And you can find these batteries all over the world.

[a64pilot]

Originally Posted by DotDun

There is no problem using deep cycle GC batteries for engine starting. You'll have way more starting current than required.

I second that as well, no issues at all, our little Diesels aren’t as hard to start as many think.

[RobD527]

The golf cart batteries I had were too big so I ended up buying 4 new group31 12v duracell batteries from sams for $400


Thank you to everyone that replied