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Refrigeration
Art,
Cycle time is dependent on a variety of factors, i.e., insulation quality, door/lid design, how often it's opened, how full it is, location in the boat, etc.
On board Kalina I converted the standard top loading ice box to a refrigerator by installing a Nova-cool refrigeration system. I added 3" of insulation to the opening lid and plugged the bottom drain to keep the cold air from running to the bilge. At the slip, sunlight exposure is on the same side as the frige. With that setup, its cycle is a 4 minute run with a 4 minute interval or 50% of the time. The system draws 5 amps so it adds up to 60 amp-hours daily. This figure decreases in the winter.
On a cruise, I need to produce 60 A-H daily just to keep up with the frige, more for lighting, stereo, blender, etc. I don't have solar yet but it's on the list. I did install a 100 amp alternator but was criticized heavily for doing so on another forum. Their feeling was the output was determined by the battery state rather than the alternator capacity (I agree totally). My position was, what if the battery bank wants more than 35A? My strategy was to reduce recharge time if possible.
Battery storage capacity is a factor too. You want enough capacity to last at least a full day to be able to choose when you recharge (run the engine or generator and annoy everyone within earshot in a quiet anchorage). An old rule of thumb is to add a battery with the addition of refrigeration.
I currently have 5 batteries on board: 4 - group 27 lead-acid batteries paired up in 2 banks for the house and 1 - group 24 isolated as an engine starter. With that, I can survive 24 hours on a single bank (G27 pair) without any regard for power conservation or recharging. In theory, I could recharge once every other day. In practice, I recharge daily, always like to have a reserve.
Finally, I don't know if this applies to our engines but I took a diesel course many years ago and the instructor felt there was nothing worse for a diesel than to run it in neutral at the dock. He said the engine takes too long to reach operating temp if at all and accordingly the nasties in the crankcase oil aren't sufficiently evaporated out causing premature wear. His mantra was if you need to run your engine, take your boat out, put some load on it. Based on what I've read on this thread, this would apply at least to our trannys.
With regard to refrigerators, when on a cruise and no shore power ( mooring) does anyone have experience with how often to run a small refrig/freezer and how often the batteries need to be recharged. Can small freezer run 4 or 5 hours on battery alone? then recharge batteries?. What cycle time is to be expected?
Cycle time is dependent on a variety of factors, i.e., insulation quality, door/lid design, how often it's opened, how full it is, location in the boat, etc.
On board Kalina I converted the standard top loading ice box to a refrigerator by installing a Nova-cool refrigeration system. I added 3" of insulation to the opening lid and plugged the bottom drain to keep the cold air from running to the bilge. At the slip, sunlight exposure is on the same side as the frige. With that setup, its cycle is a 4 minute run with a 4 minute interval or 50% of the time. The system draws 5 amps so it adds up to 60 amp-hours daily. This figure decreases in the winter.
On a cruise, I need to produce 60 A-H daily just to keep up with the frige, more for lighting, stereo, blender, etc. I don't have solar yet but it's on the list. I did install a 100 amp alternator but was criticized heavily for doing so on another forum. Their feeling was the output was determined by the battery state rather than the alternator capacity (I agree totally). My position was, what if the battery bank wants more than 35A? My strategy was to reduce recharge time if possible.
Battery storage capacity is a factor too. You want enough capacity to last at least a full day to be able to choose when you recharge (run the engine or generator and annoy everyone within earshot in a quiet anchorage). An old rule of thumb is to add a battery with the addition of refrigeration.
I currently have 5 batteries on board: 4 - group 27 lead-acid batteries paired up in 2 banks for the house and 1 - group 24 isolated as an engine starter. With that, I can survive 24 hours on a single bank (G27 pair) without any regard for power conservation or recharging. In theory, I could recharge once every other day. In practice, I recharge daily, always like to have a reserve.
Finally, I don't know if this applies to our engines but I took a diesel course many years ago and the instructor felt there was nothing worse for a diesel than to run it in neutral at the dock. He said the engine takes too long to reach operating temp if at all and accordingly the nasties in the crankcase oil aren't sufficiently evaporated out causing premature wear. His mantra was if you need to run your engine, take your boat out, put some load on it. Based on what I've read on this thread, this would apply at least to our trannys.
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