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12Vdc Refrigeration


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My apologies in advance if this topic has already been discussed to death

My wife and I have been live-aboard cruisers on our 37' sailboat for the last 8 years. We bought a Toyota motorhome last summer and are doing a few things to make our lives "aboard" easier. We have really liked our 12vdc refrigeration on the boat for many reasons. We're beginning to look at changing from our old and tired propane / AC refrigeration to a 12vdc system.

We'd be interested to hear of any real-world experience any of you might have regarding using 12vdc refrigeration in a Toyota RV.

We already have 2 120w solar panels, a Frigiboat compressor (we'd need to add the fan cooling add-on to the compressor), and a pretty good sized evaporator.

Here are a few of the many thoughts we've been tossing around:

- The boat has a house bank of 6 Trojan T-105 golf cart batteries for a total of 675w of 12vdc power. I won't even consider using this much storage on the RV due to the weight, so I'll need to come up with a reasonable compromise.

- Our most desirable camp sites tend to be in the shade.

- On the boat, we'd often sail for days on a passage and the panels and wind generator would keep the batteries charged (unless we had to run the water maker and the sun wasn't out). This included the additional loads for navigation equipment, radios, and nighttime running lights.

- Our fridge on the boat ran at about a 1/3 duty cycle, drawing about 40 amp hours per day. However, we should be able to build a better insulated efficient top opening fridge than the one on the boat. It will fit in the same or less space than the current 120vac / propane fridge.

- We'll be running the engine in the RV more often than we did on the boat, so the alternator will take care of some or most of the charging load except when we stay in one place for a while.

... and so on.

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I've got one RV with a 12 volt compressor refrigerator. Draws 2 amps @ 12 volts with a duty cycle of approx. 15 minutes per hour @ 70 degrees F. I have another RV with a cheap 120 volt AC refrigerator hooked to my "house" batteries via a 1200 watt DC-to-AC inverter. Works fine. Draws near 6 amps @ 12 volts when running but since I added 1" of extra poly-iso insulation - it easily runs a full night with just one house battery (110 amp hour).

Depending on what your style of camping and driving is - you might get by with just one "house" battery. use a pair in mine and also have two 100 amp solar panels on the roof.

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jdemaris,

What kind of 12v compressor do you have that only draws 2 amps when running? My Adler-Barbour draws about 6 amps when it's running. I haven't run the Frigiboat, yet, but it's based on the same Danfoss compressor.

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What I meant to say is they average 2 amps per hour for a 24 hour day @ 70 degrees F.

My Norcold has a Japanese 72 volt AC compressor hooked to a built-in inverter to run on 12 volts DC. It draws approx. 4 amps @ 12 volts when running.

My 5 cubic foot Sundanzer (DCR165) refrigerator with the Danfoss 10-30 volt DC compressor when running draws anywhere from 1.5 amp to 6 amps @ 12 volts. The Danfoss compressor is variable speed. This refrigerator is amazing and will use, on average, 1/2 amp per hour @ 12 volts when the temp is 90 degrees F. Technical data shows it using 14 amp-hours per day @ 12 volts @ 90 degrees F. Or - 168 watt-hours per day @ 90 degrees F.

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That sounds about right based on my experience w/ the Danfoss. Even averaging 2 amps per hour the refrigeration was the biggest electricity consumer on the boat. I've looked at the Sundanzer before and think it's a nice unit. Unfortunately, they don't seem to make one that has both a fridge and a freezer. It's also pretty spendy for my limited budget.

I believe the Frigiboat unit is also variable speed. On a boat it uses a keel cooler to cool the refrigerant - very efficient and quiet. On the RV I'll need to add the optional air cooling unit - basically a fan and a little radiator for the coolant. There's plenty of room where the old Sibir fridge sits to build a Sundanzer-like top opening box, and the evaporator can form a freezer. If I decide to go this route, I'll let you know what sort of performance I see.

Thanks for your input.

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I've looked at the Sundanzer before and think it's a nice unit. Unfortunately, they don't seem to make one that has both a fridge and a freezer. It's also pretty spendy for my limited budget.

Yes, the Sundanzer is expensive. I got mine new for around $750. I see now they are often over $1000. We use our "refrigerator" as a frig and a freezer. We just keep it turned all the way up and the stuff on the bottom stays frozen enough for our purposes. Gets down to the 20s. Not great for a long-term "deep freeze" but we don't need that. Just something cold enough to make ice-cream hard. I don't think you'll find many other 5 cubic foot refrigerators though that can run off a single 100 watt solar panel. Actually, Sundanzer claims it will run off just one 75 watt panel but that I've never tried.

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The first two years we had it - we ran it with a single 120 watt solar panel and a single 110 amp-hour battery. And that was in the middle of a mostly dark NY Adirondack woods. Never had a power problem and it was MUCH nicer then our previous Dometic 3-way refrigerator running on propane. In this area of the Adirondacks - propane costs a small fortune.

Later on - added to the solar array to make it 1000 watts - so I could run many power tools to build a house - including a power-sucking air-compressor to run a nail-gun, 13 amp power saws, etc. 1000 watts of solar and a bank of six GC-2, six-volt batteries (Trojan T-105 equivalents). Keep in mind that never is there a time that the sun hits all the solar panels. Mounted in a virtural "hole" in the forest canopy - 500 watts get morning sun, another 500 watt bank facing a different direction gets the afternoon sun.

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I have a 12 volt Norcold in my Escaper. It came out of a retired (scrapped) sailboat that was destroyed in a storm. The frig I think is a 1.7 cf. This last weekend I sat for 2 days without running the motor and the house battery was getting real low so I turned the frig off.

My wife and I don't normally stay in one spot for more one day so the electric frig works for us. If we did more extended stays I would add solar units.

If I could get a gas/electric unit for a decent price, I would pull the 12 volt. One thing I really like about the 12 volt is the ability to run when it is not even close to being level. The manual that I got from the internet says that it can run at up to 30 degrees off level.

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jdemaris,

Unfortunately, the Sundanzer won't fit in our space w/o a major refit. I did find a unit by Nova Kool that will almost be a drop-in replacement, the R5810. We're starting to lean toward buying rather than building. Has anyone had experience w/ Nova Kool? It uses the ubiquitous Danfoss compressor. Backwoodssolar.com says the single door models run at about 35 watts w/ a 30% duty cycle at 70 deg F ambient. This translates to 23.3 amp hours per day by my calculations. Of course, it probably doesn't factor in opening the door and actually using the fridge, but it sounds pretty good. After living w/ a top opening fridge on the boat my wife is ready for the convenience of a front opening fridge.

On a related note, how did you attach solar panels to the top of your Toyota? I'm considering a couple of aluminum brackets the full width of the house w/ feet tabbed on at the end for fastening to the side, rather than going through the roof.

Bob C - do you know how many watts or amps are being drawn by your 12v fridge while it's running? Do you know the duty cycle is - how long the compressor runs to maintain temperature compared to how long it isn't running?

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I would never swap out a gas fridge in a camper for an electric one. I can store far more energy in a 20# propane jug than 10 batteries. I can run my gas fridge for months on a 20# tank despite what some may claim other wise the proof is in the results. A full cylinder is less than 40# a group 24 cheapo is several pounds heaver and can run a fridge for maybe 2 days. Electric fridges on boats is pretty much the norm for safety reasons with an open flame and gas fumes. By the time you buy a electric fridge for $600 then add another $200 for solar another $150 worth of batteries just to keep things cool you have exceeded the price of a brand new gas one by a fair amount.

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Hey - "to each his own." Propane cylinders have to be refilled and in some areas that's not very convenient. Propane refrigerators also have to be level. That's one REAL nice advantage to an electric/compressor type unit. And for anyone that wants an "el cheapo" setup - a $25 AC powered "dorm fridge" from a yard-sale run with a $100 DC to AC inverter is an excellent cheap setup for an RV that's driven or run on a daily basis. Add a few inches of insulation and it can be very efficient. Also if someone chooses solar/electric - no "refilling" needed as long as the sun shines on a daily basis.

I hated having the propane refrigeration at my place in the Adirondacks. There was no place within a 70 mile round-trip to get propane except for one campground that charged a small fortune to fill a small tank.

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For anyone who wants to plan with a propane refrigerator and use some math:

A typical 4-5 cubic foot Dometic 3-way run on propane uses around 650 BTUs of energy per hour and around 16,000 BTUs per day (when it's hot out or when run on high). Note there are some newer models that claim less gas use.

A typical "factory filled" 20 lb. tank often has 15-18 lbs. of propane.

18 lbs. = 388,638 BTUs. That’s 598 hours of refrigeration. (25 days).

15 lbs. = 323,865 BTUs. That’s 498 hours of refrigeration, and 20 ½ days.

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Like I said real life those figures just don't work out. Level is relative the fridge info says level enough for personal comfort I can not do campers sitting on the side of a hill so that's not an issue. The fridge only uses that amount on high flame it gets colder at night and the sun is not shining on the condenser the usage drops dramatically. I heat my water, cook my food and cool my fridge all summer long and have never used much more than 20#. I have known people that left their fridge on by accident and went back over a month later to a cool fridge. I fill my own tanks they take 20#, exchange tanks are only filled to 15# they even tell you that on the placard they all ways beat people out of a gallon of propane.So if your out in the state parks and have 5 days of cloudy weather stop by I'll let you put your food in my fridge my lights will still be burning too. I agree with off grid modern DC fridges that is the way to go because you all ready are set up to make power in reasonable abundance for days with little solar gain. Most any camper all ready has propane tanks.

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Like I said real life those figures just don't work out.

No everyone's "real life" is the same as your's. You keep repeating that statement but doing so does not make your experience the "rule."

One case-in-point. Good friends of mine from Florida come to what's left of their old dairy farm in central NY ever late summer for two months and camp. They use my 4 cubic-foot three-way for their only refrigerator (Japanese by the way, not Swedish). Temps are usually 75-85 F during the days and 50s-60s at nights. They use a Walmart-refill so-called "20 pounder" every three weeks. 21-23 days. Dometic claims that their new generaion of propane refrigerators are much more efficient that the ones that came in our RVs. True or not - I cannot testify since I've never owned or used one. The "real life" reality is - propane refrigeration is great for some peoples's uses and electric just as great for others. Guess we need to just pick what we want. Complaining about the expense of a DC electric refrigerator is a little silly. Propane units are JUST as expensive if someone wants to go out and buy a new one.

In regard to leveling a propane unit? The vast majority of places me and my family camps are not level enough to use a propane fridge unless we jack up certain ends of our RV to level it. Plenty of places slightly cockeyed where we can sleep just fine but too slanted for the propane refrigerator. It's not exactly as if we are sleeping like mountain goats on a side-hill.

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After pricing the 12v options / sizes / features / cost / shipping, we've gone haring off in another direction. We're going to try converting a 5.2 cu. ft. 120v chest freezer into a fridge. The research I've done so far shows a lot of people having very good success doing this in off-grid situations, saving power even though it's being powered by an inverter. Not as efficient as a Sundanzer, for sure, but possibly acceptable for our needs / solar array, etc. And 1/10 of the cost of a comparable Sundanzer. I'll post "real life" results when I know more.

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Well there are cheaper alternatives to a Sundanzer. This place supplies 12 volt and ac/dc fridges to truckers. Cheaper than equivalent sized propane fridges but more efficient than going with an AC only cooler. Friend of mine put one in his Toyota motorhome and loves it.

DC

http://www.truckfridge.com/tf130.html

AC/DC

http://www.truckfridge.com/tf130acdc.html

Linda S

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After pricing the 12v options / sizes / features / cost / shipping, we've gone haring off in another direction. We're going to try converting a 5.2 cu. ft. 120v chest freezer into a fridge. The research I've done so far shows a lot of people having very good success doing this in off-grid situations, saving power even though it's being powered by an inverter. Not as efficient as a Sundanzer, for sure, but possibly acceptable for our needs / solar array, etc. And 1/10 of the cost of a comparable Sundanzer. I'll post "real life" results when I know more.

Yes, the Sundanzer is certainly pricey. I would not buy one today at plus-$1000 prices I'm seeing. In reference to "off-gridders" using AC chest freezers or refrigerators - Crosley was the #1 choice for many years. The reality is - you can take nearly any AC refrigerator or freezer and make it very efficienct by adding insulation. The Sundanzer has nearly 6" of foam around it. Not hard to do the same to any refrigerator.

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No everyone's "real life" is the same as your's. You keep repeating that statement but doing so does not make your experience the "rule."

One case-in-point. Good friends of mine from Florida come to what's left of their old dairy farm in central NY ever late summer for two months and camp. They use my 4 cubic-foot three-way for their only refrigerator (Japanese by the way, not Swedish). Temps are usually 75-85 F during the days and 50s-60s at nights. They use a Walmart-refill so-called "20 pounder" every three weeks. 21-23 days. Dometic claims that their new generaion of propane refrigerators are much more efficient that the ones that came in our RVs. True or not - I cannot testify since I've never owned or used one. The "real life" reality is - propane refrigeration is great for some peoples's uses and electric just as great for others. Guess we need to just pick what we want. Complaining about the expense of a DC electric refrigerator is a little silly. Propane units are JUST as expensive if someone wants to go out and buy a new one.

In regard to leveling a propane unit? The vast majority of places me and my family camps are not level enough to use a propane fridge unless we jack up certain ends of our RV to level it. Plenty of places slightly cockeyed where we can sleep just fine but too slanted for the propane refrigerator. It's not exactly as if we are sleeping like mountain goats on a side-hill.

Well I guess mine just must be a bit more efficient then. As far as expense they are about the same so it's a wash. The gas is simplistic that's what i like about it it's a hundred year old design that still works otherwise they would not still be making them.

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Bought a used 2-yr old Frigidaire 5.2 cu. ft. freezer for $90. At it's lowest setting over the past 25 hours it has used 0.83 kw including warm start and has maintained between 10 and -17 deg F including about 10-15 door openings. If my math is correct, and excluding expected inverter losses, this translates to about 2.76 amps per hour at 12v, or about 66 amp hours per day. Adding in another 14 amp hours per day for (guesstimate) inverter inefficiency and parasitic loss while in standby mode brings it up to a whopping 80 amp hours per day at 12vdc. Not too impressive, but then again, I won't be running this as a freezer, either.

I expect to receive my external thermostat tomorrow and will post again after I've run the thing at between 35 and 40 deg F for a while.

Edited by mustrmrk
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I was just reading an article with complaints about a new 2015 Jayco camper. Jayco Pinnacle that comes with an 18 cubic foot Samsung household-type AC refrigerator - run from an Xantrex Pro 1000 inverter and just ONE "house" battery. Jayco claims the one battery can run that refrigerator for a day and a half. Owners are complaining that seven hours is more like it. I kind of wonder what the heck Jayco was thinking with just using one battery and a refrigerator that huge. BIG issue with inverters is not so-much the battery going dead. It's the surge-voltage drop; Inverters are usually calibrated to shut down if the voltage gets below 11 volts even if for just a micro-second. Start-up surge on a big refrigerator can get to that point pretty quick with just one battery.

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Wow - sounds like the system was designed more by the marketing people than by engineers.

On a related note, when I measured the startup load on my little freezer I only saw about 2x the running load, e.g. 2.8A max starting vs. 1.2 - 1.4A running on 120vac. This is using a "Kill-A-Watt" plug in digital load meter, so I may well not be seeing a really brief surge greater than that. Most AC motors draw between 3x and 7x running load at startup. There doesn't seem to be a "display highest value" on the Kill-A-Watt like there is on my Fluke multimeter. Unfortunately, I don't have the $190 clamp on ammeter accessory. Hmm... maybe I could just insert a shunt so I can use my Fluke, instead. I'll have to think about that some more.

jdemaris - one other question - how did you physically secure your Sundanzer in your motorhome? I've been running a few ideas around but haven't come up w/ anything I'm really happy with, yet. I'd rather not have a flying fridge land on me in an accident...

Edited by mustrmrk
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We just took a short trip and left the freezer / chest fridge running w/ a watt meter on it while we were gone. It used 860 watts in the course of 56 hours to maintain 35-40 deg F. By my math, at 12 volts that works out to 15.357 amps per day or an average draw of 1.28 amps per hour. Assuming the inverter has a parasitic load of, arbitrarily, .72 amps, the total comes out to 24 amp hours per day. By comparison, the Adler Barbour fridge on my boat uses about 40 amp hours per day during average use.

Of course, the door was not opened at all for those 56 hours, so this will be a "best case" scenario. However, since the chest fridge spills so little cold air when opened, I am guardedly optimistic that this just might work out well. I'll post more "real life" results once I get the solar panels on, the fridge mounted, the inverter wired, etc., etc., hopefully within a couple of weeks.

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  • 4 weeks later...

I'm a bit disappointed in my system to date. The starting load on the compressor is way above what I initially counted on. The 600w / 1000w surge inverter I have will run the chest fridge about one start out of three - the other two trip the inverter into overload. I bought a Supco 3 in 1 Hard Start capacitor and relay, but, when I opened the access to the compressor, the wiring is not what I expected to see. There's a capacitor already in the circuit and I can't tell if it's a start or run cap. And, of course, I can't find a wiring diagram to verify my guesses. Frigidaire / Electrolux don't even have my model listed.

So I'm a bit frustrated. It looks like I may need to upgrade my inverter to the the thing to run reliably.

On a good note, it does seem to be very efficient as a fridge. If I can get it to run reliably on 12vdc I'

ll post some real life results.

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I'm a bit disappointed in my system to date. The starting load on the compressor is way above what I initially counted on. The 600w / 1000w surge inverter I have will run the chest fridge about one start out of three - the other two trip the inverter into overload. I bought a Supco 3 in 1 Hard Start capacitor and relay, but, when I opened the access to the compressor, the wiring is not what I expected to see. There's a capacitor already in the circuit and I can't tell if it's a start or run cap. And, of course, I can't find a wiring diagram to verify my guesses. Frigidaire / Electrolux don't even have my model listed.

So I'm a bit frustrated. It looks like I may need to upgrade my inverter to the the thing to run reliably.

On a good note, it does seem to be very efficient as a fridge. If I can get it to run reliably on 12vdc I'

ll post some real life results.

Do you really need that large of a fridge? My fridge size is based on shopping once a week. You don't have to store a lot of condiments in there as many of those do not need refrigeration. You can restock beverages on an as needed basis for that day's supply. The way one would use a refrigerator at home can be modified for life on the road. Its a matter of rethinking how you manage resources. I can purchase UHT milk that stores in the cabinet then when needed I pull from that back stock and put one carton into the fridge, It taste slightly different but not nasty, you get used to it.

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Yeah, it's bigger than we need, for sure - certainly bigger than our fridge on the boat. It just happened to be the smallest chest freezer I could find locally on Craigslist when I was looking for one, so I have this one by default. It looked a lot smaller before we put it in the RV <g>. And after 8 years of live aboard cruising from Maine to Panama we actually do have a pretty good handle on what we need vs. what we want to keep in a fridge. This is more a bit of an exercise in cheapness to see how inexpensively I can replace our fridge.

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The audio freaks use huge capacitors (4400 watts), maybe one these on the input of your inverter will give you the power boost you need to start your refer.

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Yeah, I followed what seemed to be a pretty informed thread on Northern Arizona Wind & Sun's forum - something about "600w inverter won't start 1.2a fridge". One guy mentioned those huge capacitors, but everyone sort of poo-pooed it. The general consensus was "capacitors might help decrease the surge time, and might help it get started, but don't hold out a lot of hope".

One intriguing idea I'd like to look into further was to install a couple of automatic (10 sec delay) valves between high and low pressure lines such that the compressor starts unloaded, then after 10 secs, begins actually compressing. Apparently that's how they do the "big stuff". Makes sense to me, but may well not be worth the cost. I'll be looking into this a bit more tomorrow.

At this point, unfortunately, it seems my most cost-effective option is to upgrade my inverter to the 1500 - 2000 watt range to insure the compressor will start reliably. Yuck.

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Yeah, I followed what seemed to be a pretty informed thread on Northern Arizona Wind & Sun's forum - something about "600w inverter won't start 1.2a fridge". One guy mentioned those huge capacitors, but everyone sort of poo-pooed it. The general consensus was "capacitors might help decrease the surge time, and might help it get started, but don't hold out a lot of hope".

One intriguing idea I'd like to look into further was to install a couple of automatic (10 sec delay) valves between high and low pressure lines such that the compressor starts unloaded, then after 10 secs, begins actually compressing. Apparently that's how they do the "big stuff". Makes sense to me, but may well not be worth the cost. I'll be looking into this a bit more tomorrow.

At this point, unfortunately, it seems my most cost-effective option is to upgrade my inverter to the 1500 - 2000 watt range to insure the compressor will start reliably. Yuck.

sounds like it. I would like a drawer fridge but might end up converting a top loading 12/ 110 marine fridge into one which would save half the cost of buying a ready made drawer fridge of similar capacity. 1.4 cubic feet is large enough for my needs. I can super insulate it by surrounding it with more foam which means lower overall power consumption. Another bonus is very light weight at only 22 lbs. It has an external compressor that can be located up to 5 feet away. That helps a lot if you have a tight space where the drop in fridge will fit but not the compressor.

This is the top loading fridge I have been looking at http://www.suremarineservice.com/C40RBP4-T.aspx . I can get it about the retailers cost through a friend of a friend as a personal favor. But that is not something I can arrange for anyone else. But I am not making any firm decisions for the moment as I have other stuff to get done first and a fridge can wait.

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I have a Norcold DE 251D installed in my Escaper. The label says that it draws 5.5 amps and I would guess that it runs about 40% of the time. When I installed the unit, I added 2" of styro on the sides and top.

My solar equipment should arrive in the next day or so and I hope to have it installed this week. The solar controller has a display that shows how much power is produced and also what the power usage has been since the panel was reset last. I will find out what my power consumption of the fridge is when I get the equipment installed.

When I replaced the fridge, I would rather have bought a propane fridge but I could not find one at a reasonable price at the time. The RV had a dorm style fridge in it when I bought it and it would not run on my inverter, it might have worked on a pure sine wave inverter but I did not have one.

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The new 2kw inverter works great. I bought a Xantrex PROwatt SW 2000 from Hodges Marine and it arrived the next day! Awesome service. I bought a chartpotter and VHF radio from them a few year back and was happy then, too.

Unfortunately, the weak Walmart marine battery that came w/ the bus can't run the fridge for more than an overnight, at best. W/ a full charge, after I run about 20 amps out of it, I'm down to 12.2v and, when the fridge pulls in, it drops to 11.5. I was pretty spoiled by the 6 Trojan T-105s I had for a house bank on the boat (675 amps total), but there's no way I'm adding that weight. I'm going to replace the group 29 marine battery w/ 2 deep cycle 6 volt golf cart batteries. Way more bottom end "oomph" to handle the 13a load when the fridge is running.

Consumption: still looking at about 5 mins every hour for a total of 26 ah/day. Inverter draws about 0.4-0.5a at rest, so add another 12 ah/day for a total of 38 ah / day, or about 10 ah/day less than the fridge on the boat.

Unfortunately, the cost of this project is growing into something more than I'd hoped for, initially. Still less than the cost of a new 12v / 120v / propane fridge big enough to suit my wife, but not by nearly as much as I'd hoped. On the other hand, if I ever need to replace the fridge all the infrastructure will be in place to do it for the cost of a used Craigslist freezer. At least it's been fun.

More when I get the batteries in.

Edited by mustrmrk
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One day the gap will narrow between house and RVs as far as powering appliances from solar goes. Until then there is no energy efficient cross over in terms of large capacity appliances from houses being well suited to RVs.

Last year's attempt in the forum on the use a big 110 volt freezer for running off of 12 volt as a fridge also failed. But you probably did not read that thread. It would have saved you some money if you had.

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Yep, must have missed that one. But I wouldn't call it a failure, yet. Just not quite the raging financial success I was hoping for <g>. Once I have it all up and running for a bit I'll post some "real world" numbers.

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Unfortunately, the weak Walmart marine battery that came w/ the bus can't run the fridge for more than an overnight, at best. W/ a full charge, after I run about 20 amps out of it, I'm down to 12.2v and, when the fridge pulls in, it drops to 11.5. I'm going to replace the group 29 marine battery w/ 2 deep cycle 6 volt golf cart batteries. Way more bottom end "oomph" to handle the 13a load when the fridge is running.

Consumption: still looking at about 5 mins every hour for a total of 26 ah/day. Inverter draws about 0.4-0.5a at rest, so add another 12 ah/day for a total of 38 ah / day, or about 10 ah/day less than the fridge on the boat.

One twelve-volt BCI type 29 deep-cycle battery from Walmart has approx. the same amp-hour capacity as one Trojan T-105 six-volt battery. Two type 29s in parallel from Walmart have equal AH capacity as two Trojan T-105s (or Deka GC-2s) in series. Only difference should be longevity. The Trojans are built to sustain around 30% more discharge cycles and are priced accordingly.

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  • 3 weeks later...

Preliminary results are in. We've just spent a week running the refrigeration on solar panels only. Granted, we've had nice weather, but the panels have had no trouble fully recharging the house batteries during the day. With the solar panels putting out nothing, we've been using about 40-45a per 24 hours. After about 50-60 hours, the inverter starts to complain about low voltage at start time only. So, not wanting to draw the house bank down below 50%, we figure we have about 2 days w/ no charging. With the solar panels, however, as long as it's not cloudy for longer than 48 hours, we're in good shape. At noon on a sunny day I've seen over 15 amps going into the batteries from our two 120w panels.

We're very happy with the way things have worked out so far.

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