Log In | Register
Skip to main content
Topic: Running Fridge with inverter (Read 674 times) previous topic - next topic
0 Members and 4 Guests are viewing this topic.
Running Fridge with inverter
Hi,

We will be taking ferry to Newfoundland tomorrow am and of course we will be asked to turn off the propane.

I was pretty sure that connecting an extention cord from inverter to the empty socket in the back of the fridge from the driver side window will save my ice cream.

I am in touch with Dave who is few days ahead of me. His message is putting some doubt on where I need to connect the inverter output. I am in touch with him but reaching out to bigger team as I do not have much time.

If I will not get correct informtion, i will not risk of putting live 110V plug to wrong place I will simply let go of ice cream and one month of food.

Thanks in advance
Re: Running Fridge with inverter
Reply #1 –
Is your 400ah battery and inverter is still independent of your Lazy Daze 110 system?  This is easily confirmed by attempting to switch your fridge to AC power while you are not connected to shore power.  If you can turn your fridge to AC, then you are ready for the ferry.

If your battery & inverter are independent, then you will need to run an extension cord from your inverter to the external panel that has the refrigerator plugged into the 110 socket.    Simply unplug the fridge and plug it into the extension cord connected to your inverter.   Then confirm you can switch the fridge to AC.

Dave

2017 TK
Re: Running Fridge with inverter
Reply #2 –
Thanks Dave for timely response.

I have very cheap/simple solution and had a independence circuit which I use for Bipap/humidifier/tube heater and use it for other purposes as well (smoothie maker etc). Side benefit is AGM batteries  never goes below 95-90% and I do expect not to worry about them for next 10 years. I did not run wires to the fuse box and circuit is entirely independent except for dc-dc charger which does not interfere as current flow only one way.

Thanks for quick information. I have the information to get it done right. I guess 400ah should be enough for 7 hrs ride. There is built in BMS, even if not enough for 7 hours it will be good enough to save the day before shut itself.

I see a empty socket available below the used socket (which I am going to use) in refrigerator compartment. Do anybody know what it is for? I tried to search database here, look at the companion and also look at Google but could not get any info. Just curious if it is connected in series with the socket which is in use and if answer is yes then I should be able to simply plug in that socket as well, right? Just curious but I got the answer and just curious. I do have the voltmeter, I can simply find out myself ... we have to report two hours before departure and I guess this will be a good activity :-)

Dave, looking forward to seeing you again .... be well
Re: Running Fridge with inverter
Reply #3 –
Quote from: Muhammad  - 
Thanks for quick information. I have the information to get it done right. I guess 400ah should be enough for 7 hrs ride. There is built in BMS, even if not enough for 7 hours it will be good enough to save the day before shut itself.

I see a empty socket available below the used socket (which I am going to use) in refrigerator compartment. Do anybody know what it is for? I tried to search database here, look at the companion and also look at Google but could not get any info.
400ah is plenty for a 7 hour crossing (really more like 9 hours when you account for loading/unlosding), I used maybe 30% on my crossing three days ago.

The 110 outlet in the refrigerator compartment is just like any other outlet in your rig, it’s got power anytime the rest of the outlets do, when you’re hooked up to shore or running the generator. 


Dave

2017 TK
Re: Running Fridge with inverter
Reply #4 –
I have crossed to & from Newfoundland on the N. Sydney/Port-au-Basque ferry many, many times over the last forty years of travel there. All I did was allow the reefer to fully cool overnight at port before boarding and turn it off at boarding without opening the doors. Then I turn the propane off at the tank as required. After arrival I turn the propane and reefer back on. I never had any spoilage or defrost with the contents.
While traveling there and you need any tips on what to see please call, text, or email me as I have extensively travelled the entire Provence.
2010 RB "Monty"  & currently: 2021 RB "Villa Verde"
2004 Born Free 26'
1998 Beaver Patriot 33'
1992 Barth Breakaway 28'
1982 Fleetwood Jamboree 23'
1982 Dolphin/Toyota 22'
Re: Running Fridge with inverter
Reply #5 –
Quote from: Mike Coachman  - 
I have crossed to & from Newfoundland on the N. Sydney/Port-au-Basque ferry many, many times over the last forty years of travel there. All I did was allow the reefer to fully cool overnight at port before boarding and turn it off at boarding without opening the doors. Then I turn the propane off at the tank as required. After arrival I turn the propane and reefer back on. I never had any spoilage or defrost with the contents.
While traveling there and you need any tips on what to see please call, text, or email me as I have extensively travelled the entire Provence.
Thanks Mike. I will take your help.

For now waiting to board and before boarding I overengineered and now fridge is on inverter.

Regards

Re: Running Fridge with inverter
Reply #6 –
I agree with Mike - only did this crossing twice, but everything survived the 8 hours just fine. The more in the freezer the longer it will stay very cold. Note the fridge will draw a lot of power in AC mode and you may deplete the batteries more than you think. If you do try the extension cord, set fridge temp setting as low as it goes...

Steve
2004 FL
2013 Honda Fit
Re: Running Fridge with inverter
Reply #7 –
Quote from: Steve  - 
I agree with Mike - only did this crossing twice, but everything survived the 8 hours just fine. The more in the freezer the longer it will stay very cold. Note the fridge will draw a lot of power in AC mode and you may deplete the batteries more than you think. If you do try the extension cord, set fridge temp setting as low as it goes...

Steve

Thanks Steve. We should have thought about it, oh well too late now. Lithium battery has 400ah capacity, it was fully charged and it has built in bms (cheap chinease battery but I saw bms shutting battery down when I was running heater from the battery last year). In the worst case fridge may not have power for some time, better than my worst case scenario.

I may have to be creative with bipap usage in next few days, as we have not much driving and dc-dc charger will not do its magic and I think we are mostly doing dry camping. We are not very lucky with sun God during this trip, no expecting much from solar.
Re: Running Fridge with inverter
Reply #8 –
YMMV, but...
When I had 300AH installed, I tested empty reefer on AC. From warm to 5 degrees in freezer overnight . Took 200AH to do so.  Running already chilled reefer shouldn't be as extreme.  Also wanted to see how fast it recharged, but series of atmospheric rivers dumped rain 9 days straight.  But that's another story
Joel & Terry Wiley
dog Zeke
2013  31 IB   Orwan   / 2011 CRV Tow'd LWEROVE
Re: Running Fridge with inverter
Reply #9 –
Quote from: Steve  - 
Note the fridge will draw a lot of power in AC mode and you may deplete the batteries more than you think. If you do try the extension cord, set fridge temp setting as low as it goes...
On my longer Alaska crossings, I did set the fridge to the second setting, rather than the usual fourth.

Didn’t need to for the shorter NL crossing.
Dave

2017 TK
Re: Running Fridge with inverter
Reply #10 –
Closure .... my ice cream surviviewed and battery also had some juice left at the end of the day .. no sure how much, i do not have meter for this battery... we kept charging our electronics with lithium battery for couple of days without any issue but I used bipap with coach battery without humidifier ... after few hrs of drive today we are back to business .....

Now I am wondering how easy it will be for my wife if she can use microwave with inverter :-)
Re: Running Fridge with inverter
Reply #11 –
 I put the closure and perhaps I should start a new thread but let's see a quick response from somebody with knowledge save some internet traffic.

Indians (atleast we) do drink lot of tea. Every few hours I will pull in a sceinic area and while I am enjoying the view Sophia warm up the water on stove and put the water in cup with some masala and tea and I feel guilty. She will not let me play with the fire :-) I am wondering if I can make her life little easy.

When I installed the battery, there was no need to put an inverter but I put one snyway now I start using it as we do more dry camping and staying longer on each spots and I got more graphics intense laptop which need more power to charge. I do have standalone battery and standalone inverter with seperate independent standard socket connected to inverter which is connected to 400ah battery.

Now the question, can I take microwave plug out and create some mechanism to have the option of running the microwave with either shore power or with inverter with a select of a switch?

No I am not ready to mess up with fuss box yet.
Re: Running Fridge with inverter
Reply #12 –
Tea with masala sounds good! Just bear in mind that the microwave oven draws upwards of 100 amps at 12 V when powered by an inverter. The propane stove may be a more practical choice.
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: Running Fridge with inverter
Reply #13 –
Quote from: Muhammad  - 
Indians (atleast we) do drink lot of tea. Every few hours I will pull in a scenic area and while I am enjoying the view Sophia warm up the water on stove and put the water in cup with some masala and tea and I feel guilty. She will not let me play with the fire :-) I am wondering if I can make her life little easy.
Get an electric water kettle (probably have some at the Canadian Tire in Corner Brook) and use it directly with your inverter, easier and quicker than the stove or even the microwave.

They even make them for 12v, but I doubt they would be very fast.
Dave

2017 TK
Re: Running Fridge with inverter
Reply #14 –
We have a 2200W inverter that allows us to use the microwave.  However, had a problem with the LD installed microwave - when cycling on, it would make a loud buzz and had to be turned off, then back on to work. Since it is the older style that adjusts power by turning power on and off, that was a problem. I replaced it with a Panasonic inverter-microwave that works just fine, since actual power is varied. It draws about 140 Amps from the batteries at high, so heating a cup of water for tea would probably take about 1.5 minutes, using 140X1.5/60 = 3.5 Ah from your LFP battery bank - and would only take 1.5 minutes!

Steve
2004 FL
2013 Honda Fit
Re: Running Fridge with inverter
Reply #15 –
Note that Larry Wade uses the same batteries and inverter I have, but a different setup, and the original microwave does not create a problem for him.

Steve
2004 FL
2013 Honda Fit
Re: Running Fridge with inverter
Reply #16 –
Hi Steve:  You probably meant "original microwave" in your above post.  That microwave found a new home in Lurlie's rig (Outback sub-group of the Caravan Club) and is much appreciated.  Thanks for the donation!    RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB
Re: Running Fridge with inverter
Reply #17 –
We leave the microwave always powered by the inverter no matter if on shore power or batteries. The microwave is usually only used for short periods for rewarming..
For making coffee or tea, the stove is a better choice.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Running Fridge with inverter
Reply #19 –
Quote
How do you get access to microwave plug?

Here's where it is on an 09 MB. In the cabinet above the sink and to the left of the microwave. The map you see in the photo is where the microwave is normally mounted.
jor
09 27' MB
10  Suby Forester
Re: Running Fridge with inverter
Reply #20 –
Thank you very much this information is big help and make our day to day life easy. My wife did not complain but sitting on dinning table in confined spac I noticed the importance of microwave functionality. I did not realized microwave role while at home ...

I did locate position in lower shelf. Your arrow points to upper shelf but close up shows socket and plug next to milk boxes which are placed in lower shelf. Just trying to help folks in my shoes.

Andy showed some calculations ... I looked at microwave label, it is rated at 1.35kw for back of envelop calculation let's say 1.4kw. If it run for an hr it will need 1.4×1000/12 = 117 amp or in other words 2amp/min. 2 cup of teas is 6 min => 12 amp and warming up curry is around 6 min as well which is also 12 amp. At this point if I perminantly connect microwave to 400 ah of lithium, I don't see any dent on the battery (Larry, if you have similar microwave as in my unit, I do not see any issue you using it perminantly with Lithium).

I do have dc-dc charger, plus I also noticed that once solar charge my coach batteries it increase the voltage and dc-dc charger start sending current to lithium. Above analysis is for my setup, please make wise decision for your set up.

Thanks again and am happy to be part of this team.
Re: Running Fridge with inverter
Reply #22 –
I always figured the fridge, microwave and drip coffee drew too much to run off the inverter and batteries.
Steve and Jill, Steve posting
1999 26.5 Mid-Bath
Re: Running Fridge with inverter
Reply #23 –
Quote from: StevenJill  - 
I always figured the fridge, microwave and drip coffee drew too much to run off the inverter and batteries.

As long as the inverter and batteries can handle the current draw, it becomes a matter of how long and how often. The fridge runs all day with a certain duty cycle that will require a lot of total watt-hours over a 24 hour period - how much depending on many internal and external factors. The microwave runs at a high consumption rate with time measured in minutes or seconds. Coffeemakers typically get the job done in a quarter of an hour or so - at high power. So, if the fridge on electric draws 350 Watts and the duty cycle is 30% it will consume 8X350= 2800 Watt-hrs a day. If starting it from warm, though, or if it is a really hot day, the duty cycle might be 80% which is 19X350= 6650 Watt-hrs a day. So the first scenario will deplete your lithium batteries by about 260 Ah, the second by over 600.

Steve
2004 FL
2013 Honda Fit