need new batteries

[Roxanne]

You guys are so great I decided to come back for more! We need new batteries. (Carver 356) We have 3 now, one dedicated to the gen and the other two start both engines and run the stuff. I am not sure all three need replacing but they are from 2011. Everything was fine until we had company. We always turn off the water pressure when we are going to be gone for a few days and sometimes the microwave and range. Somehow when our company was "helping" they flipped off the battery charger and we didnt notice until we came back a week later to dead stuff. Everything has seemed fine but last weekend (3 weeks since the incident) we anchored out for a few hours and you know it!!! Boat wouldnt start when we were ready to leave. We started the gen and it powered up the batteries but Mike says that since the batteries have been totally depleted its time for new ones. I was going to pick up a few so we would have them ready when he flys in tomorrow but seriously!! What kind? Gel? Deep Cycle? Amps? Ahhh What do I get. Be specific and I will run and get them tomorrow! Thanks!! You guys are amazing and I am learning so much

[g36]

I think some more info on how you use your boat would be helpful. Do you anchor out just for the day or overnight. Do you run your gen all the time while out? What Size Batteries And Type Are they now.? Changing type may require a different charger. Sorry there's just more to it to help with a suggestion. Imo. Might be time to consider some more capacity or what you have now may be adequate.

[tomschauer]

battery set up in the 355 -356 kinda sucks. Not much to work with without significant wiring changes. if your old batteries did the trick and lasted 6 years, I would replace them in kind.

[Samuel]

6 years with the same batteries you did great. You should replace batteries every 3 to 4 years. Replace all batteries the same time. I have a 356 carver and I use group 31 deep cycle Deka brand. When using battery switch use selector 1 or 2 not both. Both on a carver is a parallel for emergency start.

[mjk1040]

Roxanne; Samuel is right. Go to Walmart and get at least 02-Group 31 Marine Deep Cycle batteries. They may only have Group 29's now. Personally if the are all the same age I would change out all three for piece of mind. You may want to make it a habit to only have the battery selector on 1 or 2 while you anchor out so you have one fully charged battery to start ur engines.

[Midnightsun]

Walmart Canada definitely carries group 31 in Canada, not sure of availability in the states though. They are alway in stock in the typical Walmart battery rack. https://www.walmart.ca/en/ip/everstart- ... 0195362471

[AaHubb]

You should probably make sure the replacement batteries are rated as starting/deep cycle. A pure deep cycle battery isn't built to supply starting currents and would not last very long doing so regularly.
..Aaron

[RGrew176]

Source of the post You should probably make sure the replacement batteries are rated as starting/deep cycle. A pure deep cycle battery isn't built to supply starting currents and would not last very long doing so regularly.
..Aaron

I actually think that a deep cycle battery can and will last. My last boat was a Bayliner 3055 Ciera, 1999 model year. When I purchased the boat I had the dealer add 2 additional batteries. I spend quite a few weekends on the hook and I wanted to have the additional power therefore the two additional batteries.

In the spring of 2005 one or two of the batteries had reached the end of their life. I went to Sears and purchased 4 Sears Diehard Deep Cycle Group 27 Marine Batteries and installed them. I sold the boat in 2011 and I still had those same four Sears batteries. They were still going strong. Every spring after the batteries were 3 years old starting with the 2008 season I expected that one or more of the batteries would be finished.

When the 2011 season came, my last season with the boat that spring she fired right up. That is 7 seasons with the same batteries.

Now you get into the question of Cold Cranking Amps. Those batteries were rated at 650 CCA. Now most if not all of us use our boats during the warm months of the year. April to October here. Since we are not starting our boats in cold and sub-zero temperatures just how many CCA's do we really need.

All I am saying is that it is possible that you could install all deep cycle batteries and have no issues. I certainly did not.

Now with my Carver I have what are called Dual Purpose batteries or Deep Cycle and Starting. So far no issues this season with starting or spending time on the hook.

I am not recommending one or the other it is just that in my experience over 7 years I found that Deep Cycle batteries performed flawlessly. And I am in no way trying to say that your assessment is not correct. Your experiences may differ from mine therefore your assessment differs from mine, so please do not take offense at my posting.

[km1125]

Deep Cycles would be fine as long as they can provide sufficient MCA (marine cranking amps) for the engines you have. This is the same as CCA but instead of being rated at 0 degrees F, they're rated at 32 degrees F. The same battery will be rated for a MCA about 25% higher than its CCA.

Really need to know what size fits. I don't have a 356, so I can't comment on that. Regardless of what is already in there, if I could fit a larger battery, I would consider it.

[Viper]

Assuming you have a battery selector switch; you'd have to confirm but typically on your battery selector switch if applicable, the #1 position is usually the engine start bank which should be comprised of Start Batteries for starting your engines. The #2 position on the switch is usually the house bank used for running everything else which should contain Deep Cycle batteries. Killing all the batteries at once indicates that you are not managing bank selection with this switch and are leaving it in the "ALL" position which is not desirable for the very reason you've just experienced. When you leave the switch on "ALL" you are combining ALL the batteries together and will drain them all at the same time leaving you no power to start your engines. When out on the water and anchored, switch to the house bank. When ready to leave, switch to the starting bank before starting your engines.

How much capacity the house bank should have really depends on the type of boating you do but you should be sticking with Deep Cycle batteries for that purpose. If you have big block engines, and especially EFI, you should not go with anything less than 800CCA/1000MCA. Personally I am not a big fan of the dual purpose design simply because they can only be a compromise at best between a good starting battery and a good deep cycle battery. The physical design requirements for the two types of loads are different from each other so the best you can do in combining them into one battery is to give up the best of both designs. To hope of having the batteries as long as they were designed for, you should not use deep cycle batteries to start an engine or a start battery for regular steady depleting loads. It's not what their physical makeup was designed for. Not saying it can't be done, but combine that along with all the other variables involved that affect battery longevity and you could be vastly reducing their life expectancy.

Proper battery design, usage, and maintenance is key to longevity. If you buy cheapies then you can probably afford to replace them every few years but if you spend some serious cash on really good dependable units, the last thing you want to do is use them incorrectly for a load they were not specifically designed for. IMO of course