Trailer Electrical Help

ewatts2003 · 05-13-2019, 08:41 AM

Good morning all!

I am wanting to add a mini fridge to my trailer for comp use. Since I usually can't take off work on Friday I will take my trailer to the site on Thursday and not arrive back until Friday evening. I've noticed that some comps do not allow power hookup until Friday morning so do you guys have a suggestion for a power source from the time I leave home until I arrive to plug into comp power? I will be doing some simple 120v wiring in the trailer. Is there a good deep cycle/inverter setup that I can install just to keep the fridge cool for about 36-48 hours? Thanks in advance!

Eric

DoctorCueNC · 05-13-2019, 08:43 AM

You would have to see how much amp the fridge pulls but I got a decent deep cycle battery that’s used with a solar system from harbor freight.

ewatts2003 · 05-13-2019, 08:50 AM

Quote:

Originally Posted by DoctorCueNC

You would have to see how much amp the fridge pulls but I got a decent deep cycle battery that’s used with a solar system from harbor freight.

That is kind of what I am leaning towards. Once I am set up at the comp I will use the power provided, and I know that the fridge will hold temp without opening the door for quite a while, but I would hate the take the chance on something happening out of my control.

Untraceable · 05-13-2019, 09:51 AM

Many times what’s officially said (no power till Friday) and what actually occurs are 2 different things. Jugs of water frozen in the fridge may help, but coolers are the most reliable. I’ve seen people even with power not get their fridges below 50 just because of the heat in the trailer

Ron_L · 05-13-2019, 10:15 AM

As mentioned, you need to know the power draw for the fridge, and remember that is the draw at 120V. The current draw at 13.8V from a battery will be a lot higher.

WARNING! Math follows

So, I looked up a 2.6 Cu. Ft. mini fridge and it draws 1.5A at 120V. Using Power=current X voltage, or 1.5 X 120. That is a total of 180W.

Now, let's figure the current draw at 13.8V. That formula is Current=Power/Voltage so 180/13.8, which is 13A. The inverter is not going to be 100% efficient, so let's assume 90% efficient, so that means that the battery has to supply about 14.5A.

Now, assume a Group 28 battery, that typically has a capacity of 105 amp hours. That means that a single Group 27 battery will last 105/14.5, or about 7 hours. You can get a Group 31 battery or put two group 27 in parallel if you need more time.

Sorry for the math

Getting the fridge to temp at home, and then using a small generator when you get on site would probably be a better solution. The fridge will hold temp for a few hours, I would think.

ewatts2003 · 05-13-2019, 10:35 AM

Quote:

Originally Posted by Ron_L

As mentioned, you need to know the power draw for the fridge, and remember that is the draw at 120V. The current draw at 13.8V from a battery will be a lot higher.

WARNING! Math follows

So, I looked up a 2.6 Cu. Ft. mini fridge and it draws 1.5A at 120V. Using Power=current X voltage, or 1.5 X 120. That is a total of 180W.

Now, let's figure the current draw at 13.8V. That formula is Current=Power/Voltage so 180/13.8, which is 13A. The inverter is not going to be 100% efficient, so let's assume 90% efficient, so that means that the battery has to supply about 14.5A.

Now, assume a Group 28 battery, that typically has a capacity of 105 amp hours. That means that a single Group 27 battery will last 105/14.5, or about 7 hours. You can get a Group 31 battery or put two group 27 in parallel if you need more time.

Sorry for the math

Getting the fridge to temp at home, and then using a small generator when you get on site would probably be a better solution. The fridge will hold temp for a few hours, I would think.

I love math!! Lol. The fridge is at home so over lunch I'm going to go see if I can find the info I need. I have 2 group 27 deep cycles in my boat that I can easily pull out for a weekend so I may go that route with a good inverter. If I could just shut the business down on Fridays I wouldn't have this issue!!

InThePitBBQ · 05-13-2019, 11:41 AM

Have you considered the starting amps of the compressor using an inverter?

Consider an RV ammonia refrigerator instead those run on 120V to power the heating element when power is available and switch to propane and 12VDC battery source when you can't plug them in.

ewatts2003 · 05-13-2019, 11:51 AM

Quote:

Originally Posted by InThePitBBQ

Have you considered the starting amps of the compressor using an inverter?

Consider an RV ammonia refrigerator instead those run on 120V to power the heating element when power is available and switch to propane and 12VDC battery source when you can't plug them in.

I have looked into this before, but since the trailer is not a dedicated comp trailer I have a hard time spending the money on a 3 way RV fridge and the hookups to use a few weekends out of the year. If I get more involved in the comp scene this will definitely be the route I go.

toys4dlr · 05-13-2019, 01:40 PM

Not the cheapest fix, but it looks cleaner than a quality inverter and 2 deep cell batteries.

https://www.costco.com/Goal-Zero-Yet...100469980.html

I don't know how reliable your power is at comps in your area, but out here it is sketchy at best if it is avaiable at all. I had the inverter with deep cell batteries set up when I cooked on pellets, cause I just could not trust the power at the comps. Now I have a honda EU3000,

ewatts2003 · 05-13-2019, 11:06 PM

Quote:

Originally Posted by Ron_L

As mentioned, you need to know the power draw for the fridge, and remember that is the draw at 120V. The current draw at 13.8V from a battery will be a lot higher.

WARNING! Math follows

So, I looked up a 2.6 Cu. Ft. mini fridge and it draws 1.5A at 120V. Using Power=current X voltage, or 1.5 X 120. That is a total of 180W.

Now, let's figure the current draw at 13.8V. That formula is Current=Power/Voltage so 180/13.8, which is 13A. The inverter is not going to be 100% efficient, so let's assume 90% efficient, so that means that the battery has to supply about 14.5A.

Now, assume a Group 28 battery, that typically has a capacity of 105 amp hours. That means that a single Group 27 battery will last 105/14.5, or about 7 hours. You can get a Group 31 battery or put two group 27 in parallel if you need more time.

Sorry for the math

Getting the fridge to temp at home, and then using a small generator when you get on site would probably be a better solution. The fridge will hold temp for a few hours, I would think.

The fridge is a 4.3 cu ft with a top freezer. The info on the label reads as follows:

Voltage 115v
Frequency 60Hz
Current 1.0A
Power 70w

Ron_L · 05-14-2019, 07:40 AM

Quote:

Originally Posted by ewatts2003

The fridge is a 4.3 cu ft with a top freezer. The info on the label reads as follows:

Voltage 115v
Frequency 60Hz
Current 1.0A
Power 70w

OK... I modified my math below...

Quote:

Originally Posted by Ron_L

1.0A at 120V. Using Power=current X voltage, or 1.0 X 120. That is a total of 120W.

Now, let's figure the current draw at 13.8V. That formula is Current=Power/Voltage so 120/13.8, which is 8.7A. The inverter is not going to be 100% efficient, so let's assume 90% efficient, so that means that the battery has to supply about 9.7A.

Now, assume a Group 28 battery, that typically has a capacity of 105 amp hours. That means that a single Group 27 battery will last 105/9.7, or about 10.8 hours.

Also, one thing I didn’t mention. All of the DC side of the math is based on 13.8V, but as the battery charge level drops, the voltage will drop, so the current will increase to keep the power out the same, so real life use will likely be less time.

bpeyton89 · 05-14-2019, 10:06 AM

To be 100% honest the mini fridge is not likely to hold more than a large Coleman cooler, and ice is certainly cheaper than maintenance on the battery. Personally I'd avoid the math, put your supplies in a cooler on ice, and enjoy the piece of mind.

Don't get me wrong, I love my apartment size fridge in my trailer, and never want to cook without it, but if we have to drop off early and there is no onsite power (city power) everything is going in a cooler until we are onsite. I don't even trust the temporary generators. It's not worth the risk.

Also the math is simpler 1 20lb bag of ice will last your at least 24 hours.

ewatts2003 · 05-14-2019, 11:58 AM

Quote:

Originally Posted by bpeyton89

To be 100% honest the mini fridge is not likely to hold more than a large Coleman cooler, and ice is certainly cheaper than maintenance on the battery. Personally I'd avoid the math, put your supplies in a cooler on ice, and enjoy the piece of mind.

Don't get me wrong, I love my apartment size fridge in my trailer, and never want to cook without it, but if we have to drop off early and there is no onsite power (city power) everything is going in a cooler until we are onsite. I don't even trust the temporary generators. It's not worth the risk.

Also the math is simpler 1 20lb bag of ice will last your at least 24 hours.

After looking into everything I have a plan figured out. The MAIN reason I want the mini fridge is to be able to stack turn-in boxes after they are made to keep them cool and not have them in a cooler with the risk of being damaged. I'm going to take the fridge with and just plug it in as soon as I get there. I will keep the garnish in the cooler and by the time I get around to making the boxes the fridge should be cooled down enough for my liking.

If I get to a point where I can compete more and have a dedicated trailer we will explore other options!! Thanks everyone for the help!

Untraceable · 05-14-2019, 01:09 PM

15 dollar cooler and a 20lb bag of ice keeps the garnish cold, then houses the made boxes safely.

egorham · 05-14-2019, 03:50 PM

I agree with the cooler and Ice option. Setup everything at the comp except the meat an garnish on Thursday, load the cooler at home Friday morning, check it throughout the day and bring it with you.

For the garnish I just use a moist paper towel with a small zip lock bag of ice on top, close the lid and place all 4 clam shells inside a soft sided insulated cooler bag (mine is 20x13x14 and cost $10-$15). Find a shady spot in your cook site so the bag is not in the sun. Because the bag is collapsible it does not take up much room and I have never had the garnish dry out or wilt.

05-13-2019, 08:41 AM	#1
ewatts2003 Full Fledged Farker Join Date: 08-05-17 Location: Blair, NE	Trailer Electrical Help Good morning all! I am wanting to add a mini fridge to my trailer for comp use. Since I usually can't take off work on Friday I will take my trailer to the site on Thursday and not arrive back until Friday evening. I've noticed that some comps do not allow power hookup until Friday morning so do you guys have a suggestion for a power source from the time I leave home until I arrive to plug into comp power? I will be doing some simple 120v wiring in the trailer. Is there a good deep cycle/inverter setup that I can install just to keep the fridge cool for about 36-48 hours? Thanks in advance! Eric __________________ Traeger Texas Elite w/ Smoke Daddy controller and UDS w/ Smoke Daddy pellet hopper

05-13-2019, 08:43 AM	#2
DoctorCueNC On the road to being a farker Join Date: 04-16-15 Location: Angier, NC	You would have to see how much amp the fridge pulls but I got a decent deep cycle battery that’s used with a solar system from harbor freight. __________________ DoctorCueNC - MCBJ - 270 Smokers KC - Grilleye - Oakridge BBQ - B&B Charcoal

05-13-2019, 10:15 AM	#5
Ron_L Moderator Join Date: 12-09-04 Location: Wandering, but not lost Name/Nickname : Captain Ron	As mentioned, you need to know the power draw for the fridge, and remember that is the draw at 120V. The current draw at 13.8V from a battery will be a lot higher. WARNING! Math follows So, I looked up a 2.6 Cu. Ft. mini fridge and it draws 1.5A at 120V. Using Power=current X voltage, or 1.5 X 120. That is a total of 180W. Now, let's figure the current draw at 13.8V. That formula is Current=Power/Voltage so 180/13.8, which is 13A. The inverter is not going to be 100% efficient, so let's assume 90% efficient, so that means that the battery has to supply about 14.5A. Now, assume a Group 28 battery, that typically has a capacity of 105 amp hours. That means that a single Group 27 battery will last 105/14.5, or about 7 hours. You can get a Group 31 battery or put two group 27 in parallel if you need more time. Sorry for the math Getting the fridge to temp at home, and then using a small generator when you get on site would probably be a better solution. The fridge will hold temp for a few hours, I would think. __________________ "Ron Rico, Boss. You can call me Captain Ron..." Naked Fatties Rock! PKGo X 2/PK360/Weber Q1000/Blackstone Camping Griddle/Pit Boss Pro Series 850

05-13-2019, 11:41 AM	#7
InThePitBBQ is One Chatty Farker Join Date: 01-31-19 Location: South Bend, IN Name/Nickname : Bob	Have you considered the starting amps of the compressor using an inverter? Consider an RV ammonia refrigerator instead those run on 120V to power the heating element when power is available and switch to propane and 12VDC battery source when you can't plug them in. __________________ Shirley Fabrication 24 X 70 elevated straight back "Fire for Effect"

05-13-2019, 01:40 PM	#9
toys4dlr is one Smokin' Farker Join Date: 08-02-07 Location: Phoenix, AZ Name/Nickname : David	Not the cheapest fix, but it looks cleaner than a quality inverter and 2 deep cell batteries. https://www.costco.com/Goal-Zero-Yet...100469980.html I don't know how reliable your power is at comps in your area, but out here it is sketchy at best if it is avaiable at all. I had the inverter with deep cell batteries set up when I cooked on pellets, cause I just could not trust the power at the comps. Now I have a honda EU3000, __________________ Q-To-U-BBQ in Cave Creek, Arizona (RIP 2020) 2010, 2011 and 2019 Best BBQ in N. Phoenix Toys 4 BBQ'N Competition BBQ Team 4x Hunsaker Drum Smokers FEC 100 (sold), FEC 120 (sold), FEC 240, FEC 500 (sold), PG 500 Shirley Fab 52 x 24 Patio (sold) 250 gallon trailered Moberg

05-13-2019, 09:51 AM	#4
Untraceable Babbling Farker Join Date: 05-19-11 Location: EAD	Many times what’s officially said (no power till Friday) and what actually occurs are 2 different things. Jugs of water frozen in the fridge may help, but coolers are the most reliable. I’ve seen people even with power not get their fridges below 50 just because of the heat in the trailer

05-14-2019, 10:06 AM	#12
bpeyton89 Full Fledged Farker Join Date: 05-28-14 Location: St. Louis, MO	To be 100% honest the mini fridge is not likely to hold more than a large Coleman cooler, and ice is certainly cheaper than maintenance on the battery. Personally I'd avoid the math, put your supplies in a cooler on ice, and enjoy the piece of mind. Don't get me wrong, I love my apartment size fridge in my trailer, and never want to cook without it, but if we have to drop off early and there is no onsite power (city power) everything is going in a cooler until we are onsite. I don't even trust the temporary generators. It's not worth the risk. Also the math is simpler 1 20lb bag of ice will last your at least 24 hours.

05-14-2019, 01:09 PM	#14
Untraceable Babbling Farker Join Date: 05-19-11 Location: EAD	15 dollar cooler and a 20lb bag of ice keeps the garnish cold, then houses the made boxes safely.

05-14-2019, 03:50 PM	#15
egorham On the road to being a farker Join Date: 04-21-14 Location: Lafayette	I agree with the cooler and Ice option. Setup everything at the comp except the meat an garnish on Thursday, load the cooler at home Friday morning, check it throughout the day and bring it with you. For the garnish I just use a moist paper towel with a small zip lock bag of ice on top, close the lid and place all 4 clam shells inside a soft sided insulated cooler bag (mine is 20x13x14 and cost $10-$15). Find a shady spot in your cook site so the bag is not in the sun. Because the bag is collapsible it does not take up much room and I have never had the garnish dry out or wilt.