[Minnewaska]

Our fridge and freezer come on in the Spring and stay on, until she is hauled back out in the Fall (other than for an occasional cleaning or defrosting). Lots of time plugged into her slip, of course, but something on the order of 100 days off the dock too. It‘s purely a matter of battery capacity and recharging resources (alternator, generator, portable generator, solar or wind). The outcome of having full time refrigeration is very common. How you get there is variable.

 

[Minnewaska]

I've found a number of this company's articles very informative. Coincidental that the most recent is on holding plates, but there are three dozen on refrigeration alone. Worth poking through.

Marine Refrigeration Blog | Coastal Climate Control - Blog

Coastal Climate Control, marine refrigeration, air conditioning, flexible and walk-on solar panels, systems monitoring, and battery solutions, including lithium batteries

www.coastalclimatecontrol.com

 

[Minnewaska]

When I talk to people at the docks I am always astounded at how many people do not understand their battery system at all! It's no wonder so many people think it is normal to replace a battery bank every 5 years!

You're right about the general lack of understanding. No doubt we were all there at one point. Batteries used to give me a headache.

There is, however, another way to look at the 5 yr replacement window. As the informed realize, there is a correlation between the depth of discharge of a lead acid battery and the number of times it will take a charge. The accepted limit of 50% isn't really a magic number, it's just considered an acceptable trade off. If one were to manage to only discharge 20% of capacity, as an example, the battery would accept substantially more recharge cycles. Many folks spend money on extra batteries, or on passive charging systems (solar/wind), and this is ultimately the effect. Longer longevity, due to much more shallow discharge levels. However, at a price. In theory, replacing half the number of batteries every 5 years, is no different than twice as many every 10 years.

Of course, there are many other factors at play too. Some boats are more or less power hungry or are space limited and can't add bigger banks. Some chemistries, like AGM, must get to a good full charge to insure service life, not solely mange discharge levels. And the headache ensues.

 

[Minnewaska]

I am curious about how people are using their refrigerators/"ice boxes"

Not very different from home. The usual beverages, food, condiments, etc. It's stocked at all times, like it is our summer home. Which is exactly what it is. In Maine at the moment.

 

[Minnewaska]

Well I did my little experiment, turned of the shore power to see how much power the refrigerator uses.... Temp. here was, high of 93 and low overnight of 82. It consumed 65 amp hours. The compressor must have been on almost constantly to use that much. That surprised me.

2.7 amps per hour, over 24 hours? I'd guess the compressor was running about half the time. That's pretty reasonable, especially in hot weather. Were you surprised it wasn't more?

 

[Minnewaska]

Do keel cooled refers have fans?

 

[Minnewaska]

Just this year, I bought one of those multi-zone remote temperature gauges on Amazon for maybe $50. Mine has four zones, which is 3 remote, plus the temp in the room you put the display in. The sensors go in the refers and freezer, so at a glance, I can tell all is working properly. Awesome piece of mind and also helps identify when defrosting is needed or other maintenance.

 

[Minnewaska]

They can have both some people forgotten to turn it off when the boat was out of the water

I asked because, for 20 years, all I've had was frigoboat keel cooled or raw water cooled refrigeration and don't ever recall having a fan. Including now.

 

[Minnewaska]

Only my freezer is raw water cooled. I don't really understand why it's different than my keel cooled fridges. What I do know is the keel coolers have never ever failed in my lifetime. The raw water pumps have. I'd love to have the ability to switch it over, while repairs are effected over the time it takes to source a new pump. Maybe that means a fan. But I am suspicious it would be enough.