Weird 12V Power plug behavior.

Wanderman
Wanderman Solar Expert Posts: 180 ✭✭✭
With new, fully charged batteries and a voltage reading of 12.58V at the receptacle, everything BUT a 12 Hair Dryer will work. The fuse is not blown or blowing, I tried connecting a different style 12 V cigarette lighter receptacle. No dice. Plug it in someplace else. Works fine. Just not at this ONE outlet.

Any ideas what to check. Polarity is fine, voltage is fine....wiring is of sufficient gauge for 15+ amps at 4 feet.

Weird!

Rich

Comments

  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    Re: Weird 12V Power plug behavior.
    Wanderman wrote: »
    With new, fully charged batteries and a voltage reading of 12.58V at the receptacle, everything BUT a 12 Hair Dryer will work. The fuse is not blown or blowing, I tried connecting a different style 12 V cigarette lighter receptacle. No dice. Plug it in someplace else. Works fine. Just not at this ONE outlet.

    Any ideas what to check. Polarity is fine, voltage is fine....wiring is of sufficient gauge for 15+ amps at 4 feet.

    How low does the battery voltage get when you try to run the hair dryer? --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Weird 12V Power plug behavior.

    Have you considered an Exorcism ?
  • zoneblue
    zoneblue Solar Expert Posts: 1,220 ✭✭✭✭
    Re: Weird 12V Power plug behavior.

    For a change im going to be the one to say it: a 12v hair dryer... really?

    0. Not sure a hairdryer is something that should in general be hoped to run off an RV sized system (where 12v systems are most often found). If it isnt an RV, and, you have non trivial loads then your battery voltage is too low.
    1. You mention cig lighter sockets. Having a small contact surface, they arent designed to carry large loads.
    2. Hairdryers use lots of power, 1kW+. On 12v thats a lot of amps, and the whole system will need to be designed to support those amps. Fat fat wires, big bank, good connections.
    3. The fact that the fuse isnt blowing suggests one of two things, the fuse is too big, or the losses in the system are preventing the required amps from developing.

    Really its a miracle that it runs at all, so your experience is in fact not weird but 100% fully expected!
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Weird 12V Power plug behavior.

    Obviously that one particular outlet does not make proper contact with the hair dryer's plug, most likely the center (positive) terminal. This type of connector is notoriously unreliable.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Weird 12V Power plug behavior.

    This 12 volt hair drier is rated at 14 Amps (thank you ILFE):

    http://www.campingworld.com/shopping/item/12v-hair-dryer/56981

    Most cigarette lighter plugs are rated at 10 amps maximum--A few may have a 15 amp fuse.

    You should really think about using some other connector (like Anderson Power Pole) for heavier/reliable DC connections/plugs.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ILFE
    ILFE Solar Expert Posts: 364 ✭✭
    Re: Weird 12V Power plug behavior.
    BB. wrote: »
    This 12 volt hair drier is rated at 14 watts:

    Hiya Bill,

    I think you meant to type "amps"?
    Paul
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Weird 12V Power plug behavior.

    You are correct ILFE. :blush:

    Fixed.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Wanderman
    Wanderman Solar Expert Posts: 180 ✭✭✭
    Re: Weird 12V Power plug behavior.

    OK...I tested all the voltages across all the fuses and sockets. Within +- .2 Volts.

    I did manage to blow a fuse, and half of the LED lighting went dim. Not OFF just DIM. Socket still worked for a phone charger, but I found a blown fuse. Looks like power is miswired someplace. If the fuse is blown, I should have no power...not half power!

    Rich
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Weird 12V Power plug behavior.
    Wanderman wrote: »
    OK...I tested all the voltages across all the fuses and sockets. Within +- .2 Volts.

    I did manage to blow a fuse, and half of the LED lighting went dim. Not OFF just DIM. Socket still worked for a phone charger, but I found a blown fuse. Looks like power is miswired someplace. If the fuse is blown, I should have no power...not half power!

    Rich

    Depending on what circuit loads are involved there could be continuity through a load that is energizing another outlet. Look for faults on the negative side first. You see this a lot with vehicles: bad connection on a tailight, for example, that lights dimly because it is making circuit completion through another bulb.