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Inverters

Comments

  • Registered Users, Registered Users 2 Posts: 25,490 ✭✭✭✭coylemj


    Divide the power (P) by the voltage (V) and you get the current (I). You also have to adjust for the inverter efficiency, some of the power will be lost. Which is why that gadget has two cooling fans.

    2,600 watts divided by 12 volts equals 216.66 amps. They're claiming an efficiency of >90% so taking it as 90%, you need to divide that current by 0.9 which yields 240 amps.

    Doing it backwards, you will draw 240 amps at 12V which equals 2880 (240*12) watts but you will lose 10% to heat so the inverter will deliver a net or usable 2,600 (2880*0.9) watts.


  • Registered Users, Registered Users 2 Posts: 11,840 ✭✭✭✭Andy From Sligo


    coylemj wrote: »
    Divide the power (P) by the voltage (V) and you get the current (I). You also have to adjust for the inverter efficiency, some of the power will be lost. Which is why that gadget has two cooling fans.

    2,600 watts divided by 12 volts equals 216.66 amps. They're claiming an efficiency of >90% so taking it as 90%, you need to divide that current by 0.9 which yields 240 amps.

    Doing it backwards, you will draw 240 amps at 12V which equals 2880 (240*12) watts but you will lose 10% to heat so the inverter will deliver a net or usable 2,600 (2880*0.9) watts.

    brilliant thanks you , that looks like just the info I was looking for.

    so, operating something at 230v AC @2.6kw will require 240amps from the 12v battery - is that right?

    So a normal 12v battery in a normal petrol 1.2l car take an 012 as an example 12v wet acid battery at 50ah battery but with 460a cold cranking power - would it draw too much power because the 12v will only deliver 50ah or will it be OK because it has 460a CCA ? - I realise the engine will have to be kept running as well to keep the battery charged


  • Registered Users, Registered Users 2 Posts: 1,518 ✭✭✭Lenar3556


    brilliant thanks you , that looks like just the info I was looking for.

    so, operating something at 230v AC @2.6kw will require 240amps from the 12v battery - is that right?

    So a normal 12v battery in a normal petrol 1.2l car take an 012 as an example 12v wet acid battery at 50ah battery but with 460a cold cranking power - would it draw too much power because the 12v will only deliver 50ah or will it be OK because it has 460a CCA ? - I realise the engine will have to be kept running as well to keep the battery charged

    It’s not going to be feasible to run that load off the car for any length of time. The alternator won’t be able to keep it charged. 20% of what you are talking about might be more reasonable.


  • Registered Users, Registered Users 2 Posts: 11,840 ✭✭✭✭Andy From Sligo


    Lenar3556 wrote: »
    It’s not going to be feasible to run that load off the car for any length of time. The alternator won’t be able to keep it charged. 20% of what you are talking about might be more reasonable.

    thanks, so about 200w might get away with?


  • Moderators, Home & Garden Moderators, Technology & Internet Moderators, Regional East Moderators Posts: 12,602 Mod ✭✭✭✭2011


    thanks, so about 200w might get away with?

    Even that might be pushing it.

    A car is designed to power small additional loads such as charging a smartphone. Even when people add spotlights the impact of the additional load can be noticeable.

    The inverter posted is designed for an “RV truck” not a car.


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  • Registered Users, Registered Users 2 Posts: 11,840 ✭✭✭✭Andy From Sligo


    2011 wrote: »
    Even that might be pushing it.

    A car is designed to power small additional loads such as charging a smartphone. Even when people add spotlights the impact of the additional load can be noticeable.

    The inverter posted is designed for an “RV truck” not a car.

    thank you. thanks for your helpful answers


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