Catalina 310 Batteries

[FlyorSail]

Aloha all. My 2002 Catalina 310 has a bad battery and I want to replace both. Her previous owner put in two West Marine 8Ds, with 1150 CCA and a 225 AH capacity. He also installed a 40 Amp charger. Lots of power to be sure. My question is what is really needed in terms of CCA and AH? I can't find anything in my owner's manual. I'm looking for Gel or AGM batteries, so any recommendations are welcome. Mahalo.

 

[LeslieTroyer]

Don’t worry about CCA it’s meaningless on small diesels. You need to check the 20hr amp rating. If 225 was enough I’d probably recommend four GC2 golf cart 6V AGM’s. That will double your House capacity and last a good long time. Be sure and read @Maine Sail article on deep cycle batteries at marinehowto.com. If you don’t need capacity look at 12V sweeper batteries, they are mostly FLA and don’t have the recharge cycles of the GC2’s but purchase price is much lower.

I just got 4 235A (20hr rate) GC2’s for $620+tax but they were FLA.

Les
Sailing on Mahalo

 

[JK_Boston_Catalina310]

Her previous owner put in two West Marine 8Ds, with 1150 CCA and a 225 AH capacity.

If you have read about this before, 4Ds and 8Ds are not actually deep cycle batteries. Check out and read all the battery and electrical articles on Marine How To.com. The same author goes by Mainesail here and has his own forum section under featured contributors. Its worth reading all of that as well.

He also installed a 40 Amp charger.

What brand and model? Just because it may be newer doesn't mean it's worth much. Any other charging sources such as solar?

My question is what is really needed in terms of CCA and AH? I can't find anything in my owner's manual.

The CCA is an insignificant thing to consider on our engines. I have successfully started mine on nothing but a small lithium jump pack. Its more about how you use your boat and what equipment you have on board. For instance I live full-time and cruise my 310. I run the refer, fans, LED lights, a water maker, etc. off of the batteries. I have 4 6volt golf cart batteries in series and parallel to give me around 450 Ah (225 Ah usable). I wish I could double that and may someday with lithium ion. But that's about the max you can fit in the battery box area with traditional batteries. If you read through my blog you can see how to set this up. I also have 500 watts of solar panels and live almost entirely off the grid. I went almost 2 years without touching a dock until I got one in PR for hurricanes Irma and Maria. I haven't been on a dock since late September of last year. I go through about 100 Ah a day if not a little more when watching something on the laptop and with charging phones, cameras, iPads, etc.

I'm looking for Gel or AGM batteries, so any recommendations are welcome.

Do you have a high quality charger and does the boat live plugged in at the dock? If the answer to both isn't "yes" then you may want to rethink this. Again, read the stuff from Mainesail for the why.

Good luck and fair winds,

Jesse[/quote][/quote]

 

[jssailem]

@FlyorSail to the info @LeslieTroyer and @JK_Boston_Catalina310 provided.

The articles here and on MaineSail's website are the best. He provides a detailed breakdown how to look at costs of your battery. Initial price is only the beginning.

I feel one of the keys is to figure out how you want the batteries to work for you. As JK indicates you need to look at the AmpHr value and divide it by 2 to get the usable number of amps the battery can provide. (All explained by MaineSail)

If you have not yet done a Day powers usage worksheet, I suggest you make a list of the amp hours each of the electrical systems you think you use in 24 hours. This will give you an idea of how big (how many amp hours) the battery bank should be. 100 amp hours a day is a lot.

As you will find in the MaineSail info batteries have a cycle rating. True deep cycle batteries have thick lead plates. These plates can recharge more cycles than thin plates. As @LeslieTroyer states the GC batteries are thick plated and can cycle more times than a car battery (even though the car battery may say "Deep Cycle" on the label - buyer beware).

Another of the practical issues is space in the boat. It seems like there is a lot to think about, but you can get through it and you will have a great understanding of your boats electrical system.

 

[SawyerCurt]

Aloha all. My 2002 Catalina 310 has a bad battery and I want to replace both.

It has gotten pushed down past the first page of forum posts, but I posted this exact same question a couple of months ago. Probably worth a read through the replies to that one as well:

https://forums.sailboatowners.com/index.php?threads/dead-battery.191508/

 

[leo310]

Hope this helps.

 

[FlyorSail]

Wow... Great responses and advice. I much appreciate it. I think you've convinced me to go the AGM Golf Cart battery route. I have a couple of questions though. Note, I'm not well versed in this subject. First question is that if I put in the 4 6V Golf Cart batteries, do I then need a separate starting battery? Second, when the 4 batteries are in, do 2 show as "Battery 1" and 2 as "Battery 2" on my electrical panel? Thanks all!

 

[Stu Jackson]

First question is that if I put in the 4 6V Golf Cart batteries, do I then need a separate starting battery? Second, when the 4 batteries are in, do 2 show as "Battery 1" and 2 as "Battery 2" on my electrical panel?

In addition to Maine Sail's excellent website, poke around my collection here:
Electrical Systems 101 http://c34.org/bbs/index.php/topic,5977.0.html

The first dozen or so topics include answers to your questions about reserve banks and wiring.

 

[FlyorSail]

Thanks Stu. But YIKES that's a lot of material to plow through! If you could, I'd appreciate the bottom line on my questions in my last post. I promise to dig through all you sent when able though!

 

[marchem]

Wow... Great responses and advice. I much appreciate it. I think you've convinced me to go the AGM Golf Cart battery route. I have a couple of questions though. Note, I'm not well versed in this subject. First question is that if I put in the 4 6V Golf Cart batteries, do I then need a separate starting battery? Second, when the 4 batteries are in, do 2 show as "Battery 1" and 2 as "Battery 2" on my electrical panel? Thanks all!

Be sure and read some of Maine Sail's articles on battery types, to be sure you want AGM, rather than FLA (flooded lead acid), golf cart batteries.
The answer to your question is: it depends on how you wire them. If you simply replace each 8D with 2 GCs (in series) then you will have two banks of equal size, #1 and #2. That may not be the ideal setup, but it's quick and easy to do. If you decide to wire all 4 GCs together (in both series and parallel) you will only have 1 bank (but with twice the capacity), and you'll want to add a separate "Battery 2". There are many ways to wire that up. Here's how I did mine, but I've also got a lot of other pieces in there to make it work better for us.

 

[LeslieTroyer]

If you go AGM make sure your charging system can handle them for the longest life from the batteries. That mean solar/wind regulator, battery charger and alternator/voltage regulator. Preferably with one that allow for programming the various phases of the charge

This can add significantly to the cost of going AGM.

I replaced battery charger, and alternator/voltageregulator to support the AGM’s in the boat when I got it

As to bat 1/2 start. Your better off with batteries that match the load on them. Deep cycle (true) for house and CCA for start. Most of us can get by with a very small start Battery, I basically have a two switch system But the 3 switch is better. Charge the start with a ACR. The start should be the same chemistry as the house - or get a battery to battery charger in place of the ACR. Don’t split the gc2’s Into 2 banks.

Les

 

[Ron20324]

Wow... Great responses and advice. I much appreciate it. I think you've convinced me to go the AGM Golf Cart battery route. I have a couple of questions though. Note, I'm not well versed in this subject. First question is that if I put in the 4 6V Golf Cart batteries, do I then need a separate starting battery? Second, when the 4 batteries are in, do 2 show as "Battery 1" and 2 as "Battery 2" on my electrical panel? Thanks all!

No, you do not need a separate starting battery. You can start off the house bank, and the running engine should recharge all 4.

 

[Ward H]

Thanks Stu. But YIKES that's a lot of material to plow through! If you could, I'd appreciate the bottom line on my questions in my last post. I promise to dig through all you sent when able though!

I hate to speak for MS but what I came away with when reading through his articles and posts and planning my system was this:
Flooded Lead Acid batteries were the best bang for the buck for most people. If water was maintained can last a long time.
AGMs were a bit more fickle about charging and suited for particular usage.
Look at 20 Hr amp rating, not CCA etc. Two 6V GC2 deep cycles can give you 12V and 235 Amp Hrs. They have much thicker plates and will last a lot longer.
One large house bank is better than two house banks. Use the house bank for house use and for starting.
Use a deep cycle FLA G24 or G27 as an emergency reserve/emergency start. "Starter" batteries are for cars, not needed on a sailboat.
Use a Blue Sea ACR to keep the reserve battery at full charge.
Charger should be rated at 10% of battery bank.
Separate starting batteries are mostly for power or fishing boats who don't want their electronics dropping out when they are frequently starting and stopping while fishing.

At least that is what I got out of it.

 

[paulj]

This is how I installed my new batteries.

dbpaul

 

[LeslieTroyer]

@paulj. Get some MRBF fuses in there. Also what is under the tape on the red wire on the right side of the pic??

Read 1/2/both on Mainesail’s forum.