Slow Electric

Discussion in 'Off-Topic Discussion' started by Phil A, Dec 29, 2014.

  1. Phil A

    Phil A Guest

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    I should know this, having a Physics o level, but I don't :doh:

    Does resistance increase the lower the temperature of the wire? #

    It's just taking ages to charge the lappy in this frost:doh:
     
  2. pete

    pete Growing a bit of this and a bit of that....

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    I dont have any O levels, so cant say for sure, but isn't there an optimum temp for batteries etc.
    Performance charging and discharging depends on temperature.
     
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    • Phil A

      Phil A Guest

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      Seems to be, taking about an hour longer to charge, and the radio didn't want to switch on at all :rolleyespink:
       
    • clueless1

      clueless1 member... yep, that's what I am:)

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      Lots of things could be going on here.

      Resistance actually decreases as metal cools. That's why early superconductors had to be supercooled. I think the boffins have made superconductors more recently that operate at much higher temperatures but that's another topic entirely. Think about switching on an old fashioned incandescent light bulb. It is initially close to short circuit, but within a few milliseconds it heats up and its resistance increases dramatically.

      The other thing to consider is that batteries work by chemistry. Chemical reactions generally use heat to fuel them. If its very cold, the chemical reactions happen much more slowly, so batteries are less efficient at low temperatures. Its one of the three main reasons why your car battery is most likely to fail in winter.
       
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      • Phil A

        Phil A Guest

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        Ahh, more likely the latter then :thumbsup: Ta Dave :)
         
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        • HarryS

          HarryS Eternally Optimistic Gardener

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          It will be the battery performance slowing down in cold weather Zigs . You'll need to sit on them to warm them up :smile:
           
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          • longk

            longk Total Gardener

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            Temperature does alter resistance but the effect is so very slight that it is not a factor. Resistance does affect temperature however so as long as the wiring is not heating up (ie it is too light for the current) the problem is most likely the battery.
             
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            • Phil A

              Phil A Guest

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              Ta all :)

              The inverter, which usually gets hot. is hardly getting warm at the moment.
               
            • longk

              longk Total Gardener

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              Then it sounds as if generator output is low.
               
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              • Phil A

                Phil A Guest

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                I'll take it to the top of Abbotsbury hill and go down in first gear :thumbsup: DSCN0486.JPG
                 
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                • Spruce

                  Spruce Glad to be back .....

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                  H
                  Be careful what you are saying .... :lunapic 130165696578242 5:
                   
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                  • Lea

                    Lea Super Gardener

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                    Give your hamster a little coat before putting on the generator wheel! :)
                     
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                    • Phil A

                      Phil A Guest

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                      Nothing like coating the Hamster to get a good party started :)

                      Actually charged up from the solar panels today, the excess in the sun was more than enough :SUNsmile:

                      Gave the car a good run down the A35 just to make sure though, still need it to charge at night, roll on spring :rolleyespink:
                       
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                      • clueless1

                        clueless1 member... yep, that's what I am:)

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                        I presume you already know about the WD40 trick? If you give the top of the battery, especially around the terminals, a light spray with WD40, it stops condensation settling on it. Condensation is water, water is a conductor. That's one of the reasons why car batteries are more likely to fail in winter when its cold enough for condensation to form on the top of the battery.
                         
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                        • HarryS

                          HarryS Eternally Optimistic Gardener

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                          Not too sure if WD40 is a trick. As WD stands for water dispersant , its what its meant to do especially on electrics. Top quiz question ...... it was named WD40 as it was the inventors 40th recipe to perfect a water dispersant. It was originally called Rocket WD40 , as I think NASA promoted the development of it. Magic stuff though , would not be without a can :dbgrtmb:
                           
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