SeaFrost BD System

[Noreastern]

We are installing a brand new refrigeration/freezer system in our boat. Our house batteries will be 2 27 group AGM. Charging system will be 100 amp HO alternator, wing generator and solar panels. With our limited power capacity the best system we have found is the SEA FROST BD with freezer box. Has anybody here have any experience with this system? Appreciate any help and Happy Thanksgiving to all!

[skipmac]

Sea Frost makes good equipment and has a great reputation for customer service. However, almost all marine refrigeration systems use the same compressors from Danfos and properly matched to the evaporator will give similar performance and power use.

By far the biggest factor in power use will be the efficiency of the insulation and seals in the box. No refer system will give you good performance if the door seals leak and the box has 1-2" of old, spray on insulation. Also will make a big difference if you are cruising in the Caribbean in the summer when it's really hot or New England in the winter when it's really cold.

Even with a well insulated box I think two group 27 batteries will be minimal. Group 27 batteries have about 115 amp hour capacity so total of 230 amp hours for you. If you are not plugged in to power at a marina and charge exclusively from the alternator, solar, etc you can expect to use perhaps 30% max of the total battery capacity or about 75 amp hours per day. This is about enough to run a well insulated fridge and a few lights. If you use a lot of lights or have any other power draw I think this is pushing the limits but if the batteries are new and you are careful with other power use should get you by.

Will also depend on how much time you want to run the engine.

[Noreastern]

Thanks for the response Skipmac,
Box is being totally rebuilt (like everything else on this project) and is going to be well insulated. Can't remember the name of the insulation that is recommended but it did say minimum of three inches. I am thinking five to six with a double sealed top opening door. The boat we are refitting is a CCA designed 38' yawl with very limited space for batteries so we are stuck with a battery bank on the small size. While under way we will have an auto-pilot and radar if needed as added drain but we figure we could use engine when needed and add some speed. When we lay at anchor we hope to use few lights (mostly LED) and charging i-pad, laptop and kindle.
Brian

[DeepFrz]

You might want to consider LiFePo4 batteries. There is a thread running now on satisfaction and I believe it is at 100% satisfied.

[onestepcsy37]

Originally Posted by Noreastern

We are installing a brand new refrigeration/freezer system in our boat. Our house batteries will be 2 27 group AGM. Charging system will be 100 amp HO alternator, wing generator and solar panels. With our limited power capacity the best system we have found is the SEA FROST BD with freezer box. Has anybody here have any experience with this system? Appreciate any help and Happy Thanksgiving to all!

give serious thought to increasing battery capacity. four golf cart batts might not take up a whole lot more space but would double your capacity.

[robert sailor]

If you have adequate solar and wind you may be just fine as the only thing the batteries will be doing is to carry through the night. Again if you have good solar/wind then you'll be topped off by lunch time and after lunch you can charge all your computers and other devices. The downside of your smaller battery capacity will be on overnight passages as your draw from autopilot/radar/nav lites etc. will really take the power requirements up so you will have to start up your motor each night to keep thing working unless your wind generator is really putting out.

[skipmac]

Hi Brian,

Do a search on the forum and you will find several discussions on insulation. Maybe not a consensus of opinion but plenty of discussion. For the highest R-value vacuum panels are by far the best but at a very high cost and if they fail over time (which some do) then you are left with no insulation or a box rebuild (a job I just did and never want to repeat).

I went with 4-6" of polystyrene (Dow Blueboard). Tried and true solution. Some of the new stuff claims higher R-value so would allow thinner but I wanted to slightly reduce the size of the box as well so that wasn't an issue for me.

The recommendation for switching to LiFePO batteries would multiply your available amp hours but again a high cost option and require a much more hands on, very knowledgeable care and feeding to keep them happy. You current system should work at anchor but underway with the AP running you will likely have to run the engine fairly often to keep the batteries up. You don't mention starting. Do you have a separate start battery? If not the battery management is going to be much trickier.

PS
Like your choice of boats.

[SV THIRD DAY]

Originally Posted by skipmac

two group 27 batteries will be minimal. Group 27 batteries have about 115 amp hour capacity so total of 230 amp hours for you..

Actually....you will have about 100AH of usable battery capacity out of two group 27 batteries. As with all refrigeration systems the MOST important thing is your box and insulation, so if you are completely re-insulating the box then you will be many Amp-hours ahead of the game!

We make CoolBlue technautics holding plate systems which are the most efficient from an energy usage standpoint on the market, but it also costs a bit more to make them, but not having to use water cooling (even in the tropics) is a big maintenance plus. Sea Frost systems are good quality, honestly, as are most systems on the market today. Some have a 1yr warranty, CoolBlue have a 5yr, after being around since 1968 you get to weed out the bad performing parts.

What size a Box are you looking at...that will play a role in your decision tree.

[skipmac]

Originally Posted by SV THIRD DAY

Actually....you will have about 100AH of usable battery capacity out of two group 27 batteries.

IF you can fully charge your batteries every day and discharge no lower than 50% capacity then you could safely IE without damaging the batteries, use 100 amp hours per day.

However the majority of the cruisers living off the grid have found that charging the house batteries over 80% to be impractical and end up cycling the batteries between 50% and 80% SOC, hence the 30% available power for a rule of thumb. If a boat has a very large solar array, sunny cruising grounds and low power use relative to the system capacity, then it is possible to charge the batteries to 100% on a frequent basis but from all reports this seems to be somewhat rare.

Based on the OP's comments I think his charging capacity will be too limited to shoot for 100% SOC on a regular basis and he should plan on the 30% available basis.

[DeepFrz]

Based on the OP's comments I think his charging capacity will be too limited to shoot for 100% SOC on a regular basis and he should plan on the 30% available basis.

I agree with the above statement. My recommendation that the OP go LiFePo4 lithium batteries was because of his statement that he had no or limited room for a larger battery bank. His battery capacity now is way to low for a live aboard/cruising boat. Yes, there is a learning curve associated with lithium batteries but there is much information available on this forum and much help available. Yes, it is pricey, but it is probably a cheaper alternative than expanding his lead acid bank, considering the work that would need to be done to expand his battery box, etc. The last comment being made with consideration that he will need to expand his charging capacity anyway if he is to have a positive cruising experience. As one who has cruised with an inadequate battery bank size/inadequate charging capability, believe me it is no joy running the engine for hours at a time to try to keep the frig. cold. and trying to keep the voltage high enough that the radar doesn't drop out, etc, etc.

[SV THIRD DAY]

Originally Posted by DeepFrz

As one who has cruised with an inadequate battery bank size/inadequate charging capability, believe me it is no joy running the engine for hours at a time to try to keep the frig. cold. and trying to keep the voltage high enough that the radar doesn't drop out, etc, etc.

Man isn't that the truth and quite frankly the VAST Majority of Cruising/Live Aboard boats struggle with power. I saw it down in Mexico and hear it almost daily the poem goes like this:

"My refrigeration used 50AH back in the States (read cooler climate) and not is uses 100 to 150AH down here."

[Noreastern]

Thanks All, I am taking all these points seriously as I have too, wife is going to leave me if I do not get them right! Well maybe just ask me for us to quit cruising. We are not needy people and for the first year we are just planning on cruising from New England to Florida and over to Bahamas.

Box size we are looking at now is 24X24X24' with 10X8X7' freezer box inside the main box. We will have a separate starting battery. Not sure how that works with our planned charging system strategy but that would be another tread.

I am thinking we are trying to walk the line between what refrigeration and freezer we would like to have and what we can afford to have and go cruising, same as the battery capacity. Seems like the same old story for most middle income cruisers we talk to.

Thanks Skipmac, we love our good old boat!

[SV THIRD DAY]

I know the detailed prepper guys that spend years prepping for a cruise they will never leave on will disagree, but honestly where you are going in your first season...why not buy a small engle or do without refrigeration for the first season until you figure out what you want, need, like?

I know this is heresy these days in the cruiser preppper world to even say such a thing, but you are not heading off across oceans on year one anyway. The amount of pure experience and knowladge you will gain in that first year will help you then make the right decision for what you need...rather than what all the chart room experts SAY you need.

I sure wish I would have had a year of experience under my belt before spending thousands...no tens of thousands on gear I wasn't sure would work or that I needed!

[keepondancin]

Give Cleave at Seafrost a call. A good guy, cruises, and will give you some good input. The way you are setting your boat up, you should be OK. You may have to run the engine at times, but what you have is what cruisers used to use.

[skipmac]

Originally Posted by SV THIRD DAY

I know the detailed prepper guys that spend years prepping for a cruise they will never leave on will disagree, but honestly where you are going in your first season...why not buy a small engle or do without refrigeration for the first season until you figure out what you want, need, like?

I think the Engle is a great machine and would serve quite well for a small fridge. Users report they will freeze ice cream solid and still have very low power draw.

So far in my rebuild, rebuilding my fridge, which involved ripping out half the cabinet work in the galley, rebuilding, reinsulating and reinstalling the box (and the cabinets) has been by far the biggest, baddest, most time consuming part of the last 3 years. Totally thrilled with the results and since I have another 2 years before retirement it didn't really add a delay to the plans. But if I had been ready to go with only the fridge holding me back I would have really started looking at the Engle.

The only drawback to the Engle, depending on the size and model you could easily spend $600-$900 for one. If your plans (or your sailing partner ) at some time require a built in refrigerator and the budget is limited (like 99.9% of us) it might make sense to go ahead, bite the bullet and do it. However, from price shopping, the Engles do seem to hold value and you should be able to get a big part of the investment back if you do build the fridge and sell the Engle.