Refrigerator woes

[tbodine88]

My boat has two 65 amp hour marine batteries. I have just purchased an ice cold 12 volt refrigerator it works great so long as the boat is plugged into house power and the batteries are fully charged.
I bought the smallest ice Co refrigerator available it pulls 8 amps.
Yesterday I disconnected the boat and went for a ride around town on the trailer 4 hours I was gone from the house when I got back to the house the battery was already down to 10 volts.
Places to mount solar cells are small on the boat it's a small boat I have purchased a 50 w solar cell from Walmart according to my calculations I need at least two more possibly three more the power of this refrigerator. I have two spots on the cabin top that are 18 inches wide I have a Bimini I can put a flexible solar cell on. I'm just thinking that all three of these solar cells will have different output voltages and I may not be able to put them in parallel so could I put them in series and have the inverter convert down from 3 * 48 volts to 12 volts without burning out. And to complicate it all I have three weeks until my big Cruise. what do I do

[Windpilot]

You really need a more efficient fridge that draws less, bigger batteries and more solar.
You can put each panel on its own controller if you want.
The 1 or 2 50watt cheap flexible panels won't cut it for you with that set up. The 8 Amp draw is already over 100w.....
My fridge draws 4amps 15min per hour, I've probably got way more needs on my 41' sailboat than yours and have over 600w up.
I'm fine never plugging in to shore with 640ah of house battery.
Your batteries are too small to supply the fridge all night long.
I was in your situation before and this was my experience.
Others here may have better advice than mine, maybe....

[wingssail]

I think you have a tough problem to solve given the 8 amp draw of the refer, the limited battery capacity, the size of the boat, and the lack of solar.

Step 1. Get a smaller refer. 8 amps is a lot of draw for a small refer. Over 24 hours this is 200 amp hours. Maybe that is the peak, what is the average over a 24 hour period? But you maybe should get a box like an Engel which could draw less than 4 amps when running, however, even 4 amps continous will be 100 amp hours a day which is pretty high for your battery set up and solar capacity. You should be able to get down to 75ah per day, or less, 200 is outrageous).

Step 2. Get more battery power. Two 65 ah batteries will give you about 65 ah of useful power on a full charge. That's not enough to run any refer for very long, as you are finding out. You will need about 300 ah to support a small refer for 24 hours with other draws and the limitations of lead acid batteries.

Step 3. Get more recharge capacity. Solar will run about 6 hours a day. Even 150 watts of solar will only put out about 6 amps, and over six hours that gives you 36 ah each day. Not enough for the refer which needs 100 or more ah per day. So I suggest you get a small portable generator to recharge whatever batteries you wind up with.

So, smaller refer, bigger batteries, and a portable genset.

By the way, an Iceco Go20 draws on 45watt on max power, (which is 3.8 amps, or less than 100 ah per day) and less on eco mode. Not Bad.

[tbodine88]

Originally Posted by Windpilot

You really need a more efficient fridge that draws less, bigger batteries and more solar.
You can put each panel on its own controller if you want.
The 1 or 2 50watt cheap flexible panels won't cut it for you with that set up. The 8 Amp draw is already over 100w.....
My fridge draws 4amps 15min per hour, I've probably got way more needs on my 41' sailboat than yours and have over 600w up.
I'm fine never plugging in to shore with 640ah of house battery.
Your batteries are too small to supply the fridge all night long.
I was in your situation before and this was my experience.
Others here may have better advice than mine, maybe....

Yeah I agree. I was looking at fridges, I wanted a thermo-electric which draws what yours draws, I bought with out thinking. I didn't even start looking for a peltier-effect fridge until after the purchase. I'll try it for a couple of weeks under weigh. If I cant hack it with my solar installation, 200 watts once installed then I'll go back to ice until next year.

I can't even think why I would need a freezer, which the ICECO comes with.


Your 41' sailboat has twice as much surface area than my 26'.