12V fridge

[lethalee77]

Hi first post new member
i have a Waeco CR-65 fridge in a trailer, I have a 12V/100 amp hour battery which is recharged daily by 2X60W solar panels model RS-M60 which have the following specs: open circuit voltage - 21.96/short circuit current - 3.82A/max power current 3.57A/max power voltage - 17.82V The fridge draws either 5.7A or 1.9A, or 45W depending on which sheet you read (huge discrepancy trying to get to the bottom of it today). Problem is i just went away for two weeks and battery simply did not keep up, panels were used for charging from 7am to sunset (around 8:30pm daily), a few overcast days but a lot of sun also. any suggestions as to what the problem could be.

[Ryland]

First off, are your solar panels pointed at the sun or just kind of "up"?
Do you have a multi meter/volt meter that allows you to check the amp draw?
And do you know how much the fridge compressor runs?
Battery capacity is to 100% dead, using it like that and your battery might last a year if you are lucky, 50% discharge is more reasonable if you want it to last 4-5 years.
As it is I suspect you can get to 50% discharge over night if the weather is warm so right there your battery is not big enough, then you want to size your PV panels by finding your average hours of full sun per day, or sun hours, this easily seen as the number of hours per day that your panels will put out their full output, you use this number paired with your figure on your load to figure out how many panels you need figuring in battery losses as well.

[Clev]

What charge controller are you using to charge the batteries from the panels? Can you get some sense of how often the fridge runs?