Solar/Deep Cycle/Truck Camper Questions

[tortoise]

Hi All!

My first post - this forum is awesome!

I have a Ford F150 and a 70 Tortoise truck camper. I have been repairing and upgrading little by little.

I have an Emerson dorm type fridge in there. The previous owner must have taken out the original fridge. I also would be running a small under the counter dvd/tv.

I want to put a deep cycle/solar/inverter set up in the camper. The problem is this I don't know where to start. My thought was to put the deep cycle battery in the camper rather than the engine compartment on the truck and run wires to an isolator under the hood. My next thought was to put a 1000 watt inverter in the inside back of the camper to plug the main camper supply line into while traveling.

Since I am only running the fridge and the dvd/tv will a 1000w inverter handle the load? Will the deep cycle do what I need it to and will solar panels provide enough juice when parked to recharge the deep cycle?

I am new to all this so please excuse my stupidity if this isn't a good idea. If any of you have suggestions, that would be great or other websites I can check out...

Thanks!

:coffeedrink:

 

[ntsqd]

Look into the various discussion on battery combiners and dual battery installs in this forum. Bound to be a method that you like. The only difference will be the location of the battery. The old diode type battery isolators have issues and there are much better options on the market now.

What does the fridge's info panel say that it's current draw is?
Same for the dvd & tv, what do they draw?
Volts X Amps = Watts
My guess is that 1000 watts is on the edge of being able to handle the fridge start-up load when the dvd/tv are running. Starting in-rush currents can be quite a bit higher than steady-state operation currents.

On the battery search look at the Amp-Hour ("AH") ratings. First search hit explaining that term: http://www.allaboutcircuits.com/vol_1/chpt_11/3.html

 

[charlieaarons]

A 12V fridge will not require the inverter to be left on all the time. You will use quite a bit less battery running the fridge off the battery directly (12V) rather than running the inverter "on" all the time and losing 15% in inverter inefficiency. Plus, 110V fridges probably use more wattage to begin with than similarly sized 12V fridges since the 110V versions aren't designed to be used in conditions of very limited energy storage (batteries).
Our small 85L 12V fridge uses ~50A-H a day. You'll need 180-240W worth of solar cells to keep up, and you'll need a minimum of one and preferably two 100A-H batteries, since you don't want to drop below 50%. A single 4D Lifeline AGM is 210A-H.

Charlie

 

[whatcharterboat]

http://www.allaboutcircuits.com/vol_1/chpt_11/3.html

Thom, I never saw it in the link, but just something to add here to anyone buying or comparing batteries is to check the rate at which the Ah figure is given. As an example a batterry may be said to be 100Ah but it will be 100Ah @ 100hr rate but when it is discharged over a 10 or 20 hr period it will be less. So some manufacturers will advertise their product at the 100 hr rate and others at the more realistic figure of at the 20hr rate so the same battery in the example might only be 90Ah @ the 20hr rate.

So check. 2 different batteries both advertised as 100Ah may not have the same capacity at all. When you are doing your calculations you need to work on the storage capacity of a battery at the rate you are most likely to discharge it at. So if your solar is expected to replace the power daily then work on the capacity at the 20 hr rate and therefore ask the guy at the shop "So how many amp hours is that at the 20hr rate?" He must be able to tell you this or you may be getting led astray.

I'm sure you know all this but most of the public don't and can get caught out by sales guys.

 

[randman]

Tortoise,
I have a 60 watt solar system with a 7 amp charge controller coupled with 2 - 220 ah 6 volt golf cart batteries and the system seems to work well. It runs my cpap, laptop (movies and mapping) lights, water pump, forced air heater and a small 12 volt 10" flat screen tv with no problems. i would suggest finding a rv 3 way refrig with propane, they use very little propane. The electric options both 12v and 120v through the inverter really taxes my batteries.

 

[fisher205]

For your refrigerator I wouldn't recommend a 3 way frig. They have to be level to run on gas and if it switches to 12V it will run down your batteries real fast. I would look to a high efficiency 12V compressor refrigerator. Nova Kool, Norcold, Engel, and ARB are some brands to look at.
-Brad

 

[mhiscox]

For your refrigerator I wouldn't recommend a 3 way frig. They have to be level to run on gas and if it switches to 12V it will run down your batteries real fast. I would look to a high efficiency 12V compressor refrigerator. Nova Kool, Norcold, Engel, and ARB are some brands to look at.
-Brad

This is an important point. The typical RV type "absorption" refrigerator is generally about one-sixth (!) as efficient as "compressor" refrigerators such as the ones Brad mentioned.

However, even those units will be more energy-efficient than the $100 dorm units. Consumer Reports recently reported that they are extremely energy inefficient, citing a 4.6 cubic foot example that used as much power as a new full-size (18 cubic foot) refrigerator.