Carver Owners Forum

Curious if anyone anchors out most of the time and use an inverter at night to run refrigeration, what size and type battery banks are you using?

Refrigeration runs off of 12vdc so no need for an inverter. If you are referring to AC, not going to happen as the bank would need to be rather large and even then would be depleted by morning. You would then be faced with getting all that juice bank into the bank.

If you will be anchoring for extended period with no shore power, the options are to add solar and/or run the genny for meals for the high draw items and at the same time charging the house bank. Inverters work but you need to consider the power drawn from the battery goes out much faster than what can be put back in for items like a cooktop or water heater or even AC which I refer to as high draw items. If your wife needs the hair dryer, time it for when you need the generator any way or simply use the generator. Just managing high draw items when at anchor will make a huge difference on available house bank power in the long run assuming one has a large inverter that is.

Personally I do have a larger inverter which is really only used for the coffee machine on those mornings when I am up earlier than others or at an anchorage in the wee hours of the morning.

All good points Hans. I understand the usage of inverters and solar as we had a cruising sailboat for years in which we lived on anchor 24/7. Our refrigerator is apartment sized 120v so I do need an inverter. My question was more to see if anyone else anchors out for extended periods of time?

Our refrigerator is apartment sized 120v so I do need an inverter

Why not just install a minimum sized inverter dedicated to the fridge. As for how much juice you will need, all depends on the fridge power draw right.

I installed a 600ah Lithium bank last year, best upgrade I have ever made. We do anchor out quite a bit, normally what brings us in is the holding tank however with 2 heads, 2 tanks and just my wife and I aboard, 5-6 days is very doable. Battery issues are a thing of the past and no longer a concern.

I think the norm here is pretty much a weekend on the hook or an extra day now and then unless vacationing on the boat.

You could definitely implement an inverter solution for just the fridge. Sure, you'll lose a little efficiency using the inverter, but a decent inverter should be 85-90% efficient. Not knowing the particulars of the fridge, you also might want to go with a pure sine wave version, which also could be useful for other things. Size the inverter at least twice the continuous rating for the fridge and you'll be covered for the start-up load (which could be 3-5x of the fridge, but only lasts for a very short time).

For a typical "apartment-sized" fridge, you'd need around 120AH of battery capacity to run it for 10-12 hours.
If you're using any type of lead-acid battery bank, that'd suggest having about 240AH of capacity in the bank. If you were using a lithium-iron bank, you could drop that down to 150AH. Note too, that you have to address the recharging when the mains or generator is running. Recharging that bank would take quite a bit longer using lead-acid than lithiums, so if you were planning on using the generator to recharge, that means the generator would have a much longer runtime. If you were planning on running the generator all during the day anyways that wouldn't be a big issue though.

Fishsail wrote:Source of the post Curious if anyone anchors out most of the time and use an inverter at night to run refrigeration, what size and type battery banks are you using?

Just one thing more to consider....if that is a newer style 120 only fridge that has green circuit boards for control.....tip, they don't like dirty power, the boards can actually be damaged given the right circumstances, I would only consider the pure wave inverters.

My house bank is made up of 6 trojan 6v t105 lead acids. A bit overkill but have no issues and my batteries last for several years. Pure sine wave inverter and victron battery monitor. I run the genny in the am to cook breakfast etc charge up the batteries and shut it down. In the evening I'm running ac to cool the boat put some more back in the house bank and enjoy the evening before shutting her down for bed.

One of my previous boats had a 120V AC only fridge in it. I hooked it up to a dedicated inverter and never had any issues. It always ran off the inverter even at the dock. How big a battery bank you need really depends on the fridge, ambient temperatures, and how often you open it to get your drinks Keep your drinks and what ever else you need to open the fridge for often in a separate cooler and that will minimize the amount of running time. Make sure your door seal is in good shape and that there is no ice accumulation on the evaporator. Good ventilation behind and under the fridge helps too, and don't let the sun shine on it through the windows.

Hans, where did you put all your batteries? I have a '92 350 Aft Cabin, room between the engines for only 4-grp 27's. I would love to add more AH but can't see where. Do you have photos? I think this would answer the OP as well.

TIA
Phil Little

I do not think we have the same storage. My lithium house bank is under the galley floor. Here is the long winded story. viewtopic.php?f=12&t=6315&hilit=Lifepo4&start=20