How much does getting food from the fridge cost?

softdownsoftdown Solar Expert Posts: 2,414 ✭✭✭✭
So I woke up early to 50.1 volts. Not bad. Got a glass of milk and turned on the router/tv/laptop power circuit.
Then the fridge compressor turned on and ran for much longer than I expected. Voltage dropped to 49.7 before the fridge was satiated.
Voltage bounced back up 49.9 with the laptop battery recharged and a game of Monopoly finished. 

Which left me wondering  - What does a glass of cold milk really cost in battery wear and tear?  When the panels are not producing energy of course...
First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries

Comments

  • mvasmvas Registered Users Posts: 345 ✭✭✭
    How long did you leave the door open?

    A quick open & close of the door?
    Then the cooling cycle should not have been that much longer than normal,
    because the "heat of capacity" of air is very low.
    After one cycle, it should be back to normal

    Did you hold the door open long enough to warm up the food?
    Now the compressor has way more cooling to do.
    It may take two longer cycles, or more.

    The longer the door is open, the more the compressor will run ...
  • 706jim706jim Solar Expert Posts: 251 ✭✭✭
    And possibly your fridge started its defrost cycle after you opened the door. Takes more power for a while when this happens.
    Island cottage solar system with 2400 watts of panels, 1kw facing southeast 1kw facing southwest 400watt ancient Arco's facing south.Trace DR1524 MSW inverter, Trace C40 PWM controller 8 Trojan L16's. Insignia 11.5 cubic foot electric fridge. My 27th year.
  • softdownsoftdown Solar Expert Posts: 2,414 ✭✭✭✭
    The door is opened twice to get milk. Maybe for 2-4 seconds each time - wild guess there. It is likely that it coincided with a cycle that was due. I'd guess the fridge runs less than 10% of the time - but sometimes it runs for awhile. I think perceptions tend to be exaggerated upon initial wakening? 

    Been record breaking hot lately. The heat in the sunroom creeps a bit and the fridge runs a lot more when it is hot and sunny. The huge freezer could also have been running. 

    The forklift battery is doing OK now that panels are actually charging it. I expect to run the freezer from two 180 watt panels starting ~October. Technically - they are 175 since I "jumped the gun" buying my solar equipment. Builders have to be optimistic I think. But in this alpine desert at almost 8000' - I'm sure they produce more than most 250 watt panels. The valley offers great water and abundant sunshine and terrific distant scenery. Other than that? Eh. 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • BB.BB. Super Moderators, Administrators Posts: 29,518 admin
    Softdown,

    I may have missed the post--What did you "fix" to get your system charging/operating properly again?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • softdownsoftdown Solar Expert Posts: 2,414 ✭✭✭✭
    BB. said:
    Softdown,

    I may have missed the post--What did you "fix" to get your system charging/operating properly again?

    -Bill
    This is referring to the auxiliary 24 volt system. The BP panels produced measurable voltage but failed to power the charge controller. The extra couple Grape Solar panels have revived the forklift battery to normal parameters. I figure that cycling it may be beneficial but I want a power outage alarm so I don't lose a freezer full of food. Thanks for reminding me about the alarm.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
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