Truck power outlet for solar panel

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I just installed a small 100 watt panel on my truck that i use for weekend breaks
is it possible to use the power outlet /cigarette lighter socket to receive power to the battery from the Charge Controller.
I don't have long commutes and was planning to use this panel to put additional charge in the battery.
Thanks
Roy

Comments

  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
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    Re: Truck power outlet for solar panel

    Yes.
    Several concerns to be aware of:
    1. The outlet may or may not be switched on and off by the ignition switch.
    2. The outlet will typically have a 10A fuse in series, so do not try to run too much current. A 100W panel will be a lot less than 10A, so you should be OK.
    SMA SB 3000, old BP panels.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,501 admin
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    Re: Truck power outlet for solar panel

    Remember--It does get back to loads...

    A 100 Watt panel in full sun will get 4-6 hours (typical) for ~9 months of the year:

    100 Watts / 17.5 volts Vmp = 5.7 amps Imp
    4 hours of sun * 5.7 Amps = 22.8 Amp*Hours

    A typical car/light truck has around an 80 AH @ 12 volt battery. And should be discharge by no more than 15% or so:

    80 AH * 0.15 discharge = 12 AH @ 12 volt car battery.

    A deep cycle battery can be discharged by 25 to 50% and still have reasonably long life.

    Sometimes, you can wedge in a true Deep Cycle battery (maybe 20% larger AH rating than a car battery) into the vehicle and be very happy.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Novaz
    Novaz Solar Expert Posts: 57 ✭✭✭✭
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    Re: Truck power outlet for solar panel

    Thanks for the replies
    the spare power socket is available in the ignition switch secondary position
    but as Bill mentioned i do in fact have room for a secondary battery so thats what i plan on doing
    as a secondary question on this would the battery have been okay receiving charge from two separate systems
    ie ,alternator and charge controller
    Thanks
    Roy
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
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    Re: Truck power outlet for solar panel
    Novaz wrote: »
    ...
    as a secondary question on this would the battery have been okay receiving charge from two separate systems
    ie ,alternator and charge controller
    The major problem would be if both the alternator and the CC were capable of supplying close to the maximum safe charge rate to the battery. When the battery voltage is low enough for the CC to be in bulk mode and the alternator is delivering its maximum output at the same time, the battery may be damaged by up to twice the normal charging current. This could cause it to overheat, overcharge and gas excessively, lose electrolyte, and even suffer plate damage from the high current density.

    If the CC's output is well below the optimum bulk charging current for the battery, then this should not be a problem.
    SMA SB 3000, old BP panels.
  • Novaz
    Novaz Solar Expert Posts: 57 ✭✭✭✭
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    Re: Truck power outlet for solar panel

    This very small system is up and running
    installed a Midnite Solar Batter Condition Meter
    the condition i see is that even with a brand new Battery its showing
    a 20% drop overnite does the battery need to be charged at full rate for a number of hours/days before it will
    show a constant 100% charged condition when the truck is not running
    with the over cast weather currently in Seattle the panel is barely showing any current despite the 22 volts registering
    My daily commute is approx 7 miles each way ,as mentioned i installed the panel and charger to see how the technology works
    in reality ,i realise that currently its the alternator that is putting charge to the battery .
    I see mention in the BCM manual of putting a switch in the power line with a fuse I have the fuse
    but do i lose much by having the LEDs alight when no power going to the battery.
    Thanks
    Roy
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
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    Re: Truck power outlet for solar panel

    It sounds like you are seeing the 'surface charge' from the alternator degrading overnight.
    To be sure tell us the voltages when you stop the truck wen you return to start the truck and the morning voltage... also at only 7 miles you're NOT getting a full charge as the charge is likely only into the BULK phase and never getting to ABSORB.
    Do you have any daily loads? The battery needs some exercise!
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
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    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • Novaz
    Novaz Solar Expert Posts: 57 ✭✭✭✭
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    Re: Truck power outlet for solar panel

    Thanks for the reply
    i will check the voltages this week,
    I have been driving with headlights on and will run the fan as well
    cant leave the park lights on as they self cancel after a while
    Roy
  • Novaz
    Novaz Solar Expert Posts: 57 ✭✭✭✭
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    Re: Truck power outlet for solar panel

    So have had the panel on truck for a week not any real sunny days this week but some interesting readings on the BCM
    5.00AM- 8.00AM- 12.00 NOON 3.00PM

    MON 70% 80% 90% 70%
    TUE 60% 70% 60% 80%
    WED 80% 80% 80% 80%
    ThUR 70% 90% 90% 70%
    FRI 90% 90% 80% 90%

    The Battery is 8 months old and the Alternator is putting out 13.9-14.1 Volts
    to me this shows that during the day the panel is not picking up enough power due to overcast weather
    and so not making up for the draw that the commute puts on battery
    the voltage from the panel is 22+/- volts
    I am not concerned about getting to 100%as i usually get one long road trip a month which should take care of that
    but would like to know if there is anything else to read from these limited results
    the overnite gain has me confused
    I will collect some more data next week and then install the second battery that will be isolated from the alternator and just receive solar power
  • ILFE
    ILFE Solar Expert Posts: 364 ✭✭
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    Re: Truck power outlet for solar panel
    Novaz wrote: »
    I am not concerned about getting to 100%as i usually get one long road trip a month which should take care of that

    You will need to bring your batteries to a full (100%) charge more frequently than once per month. Once per week is more like it.
    Paul