Battery Charging with a Generator

Discussion in 'Tech/Mech General' started by lunarman, Jul 31, 2009.

  1. lunarman

    lunarman Funster Life Member

    Joined:
    Sep 23, 2008
    Messages:
    1,569
    Location:
    South Glos
    Ratings:
    +1,088
    I have a Kawasaki 700w suitcase generator that has both 240 and 12 v outputs I can use it to charge the batteries via the 240v ehu and on board charger but would it charge quicker using the 12v output and if so would I need to connect it via some form of charge controller?
     
  2. Geo

    Geo Trader - Funster

    Joined:
    Jul 29, 2007
    Messages:
    9,975
    Location:
    Mansfield,Notts
    Ratings:
    +9,954
    It will charge more efficiantly going direct to the battery,
    check the genny spec for its charging rates it proberbly has a built in reg, given the time it will spend charging i wouldn't worry
    Geo
     
  3. lunarman

    lunarman Funster Life Member

    Joined:
    Sep 23, 2008
    Messages:
    1,569
    Location:
    South Glos
    Ratings:
    +1,088
    Thanks Geo,

    Its rated at 12v 8.5A (suitable for battery charging) with an Automatic Voltage Regulator.

    Do I just connect the Gennie to the battery without isolating the batteries or any internal wiring.

    Lunarman
     
  4. Braunston

    Braunston

    Joined:
    May 21, 2008
    Messages:
    1,415
    Ratings:
    +10
  5. Frankia

    Frankia

    Joined:
    Sep 24, 2007
    Messages:
    133
    Location:
    Lincolnshire
    Ratings:
    +0
    I have a Honda with a similar 12v out. In the 'van we also have 3 leisure batteries which are wired together with the quick release battery terminals. The inbuilt charger gives about 16Ah so:

    If I want a quicker charge up I disconnect the last battery in the run and charge that from the 12v out of the Honda whilst the 230v out is on hook up to the 'van therefore charging the other 2. This gives me a charging rate of 24Ah instead of 16.

    I don't often use this method as we have 2 X 120w solar panels on the roof that for most of the time keep us adequately supplied.
     
  6. Tony Lee

    Tony Lee

    Joined:
    Sep 28, 2008
    Messages:
    274
    Ratings:
    +1
    Most generator 12V outputs are really intended to supply around 12V (sometimes up to 17V open circuit) to things like refrigerators and the like, rather than actually charge a flat battery.
    Just because it is marked 12V, say, 8A doesn't mean it will actually deliver that current to anything other than a dead-flat battery, so it is quite possible that even a small 3-stage mains charger could do a better job than a direct connection. Optimum might be to run any large 12V load direct from the 12V output while using the mains charger to charge the battery.
     
  7. teensvan

    teensvan

    Joined:
    Jul 25, 2009
    Messages:
    63
    Location:
    Fulltime in Motorhome
    Ratings:
    +0
    Hi.

    We have a 2kva kipor geni. The 12 volt output charge is 8.5 Amp. If i connect it to the EHU the batteries are charged at up to 25 amp. Much better charge going through the EHU and onboard charger unit.

    steve & ann. ------- teensvan.
     
  8. lunarman

    lunarman Funster Life Member

    Joined:
    Sep 23, 2008
    Messages:
    1,569
    Location:
    South Glos
    Ratings:
    +1,088
    Hi Teensvan,

    I do not understand your posting how are you connecting the gennie to get 25 amp charge? It seems to say that you are connecting the 12v to the EHU.

    Lunarman
     
  9. pappajohn

    pappajohn Funster Life Member

    Joined:
    Aug 26, 2007
    Messages:
    31,258
    Location:
    YO11 2BD
    Ratings:
    +23,600
    he means connect the 230v genny to the 230v hookup socket on the van and use the onboard charger instead of the 12v facility on the genny.
     
    Last edited: Aug 1, 2009
  10. lunarman

    lunarman Funster Life Member

    Joined:
    Sep 23, 2008
    Messages:
    1,569
    Location:
    South Glos
    Ratings:
    +1,088
    Papajohn


    I still dont understand he says "much better than using the ehu and on board charger"!!

    Lunarman
     
  11. david price

    david price

    Joined:
    Sep 28, 2008
    Messages:
    387
    Location:
    Bridgenorth
    Ratings:
    +27
    Says much better going through the ehu and on board charger.
    Dave
     
  12. sandyketton

    sandyketton

    Joined:
    Aug 29, 2007
    Messages:
    334
    Location:
    South West Suffolk
    Ratings:
    +17

    Lunarman
    He actually said

    "Much better charge going through the EHU and onboard charger unit."

    Sandy:Smile:
     
  13. pappajohn

    pappajohn Funster Life Member

    Joined:
    Aug 26, 2007
    Messages:
    31,258
    Location:
    YO11 2BD
    Ratings:
    +23,600
    think you are miss-reading the post....hes saying its much better to use the gennies 230v supply plugged into the hookup socket and use the onboard charger than the gennies 12v charger direct to the battery.

    genny power output @12v = 8.5amps onboard charger output @ 230v = 25amps
     
  14. hilldweller

    hilldweller Funster Life Member

    Joined:
    Dec 5, 2008
    Messages:
    28,644
    Location:
    Macclesfield
    Ratings:
    +34,283
    There a pattern here - 12*8.5=100W. There must be a cheap 100W regulator out there that they all use.
     
  15. pappajohn

    pappajohn Funster Life Member

    Joined:
    Aug 26, 2007
    Messages:
    31,258
    Location:
    YO11 2BD
    Ratings:
    +23,600
    probably just an industry standard, Brian.
     
  16. lunarman

    lunarman Funster Life Member

    Joined:
    Sep 23, 2008
    Messages:
    1,569
    Location:
    South Glos
    Ratings:
    +1,088
    should have gone to specsave!!
     
  17. sandyketton

    sandyketton

    Joined:
    Aug 29, 2007
    Messages:
    334
    Location:
    South West Suffolk
    Ratings:
    +17
    According to the handbook for my 2005 Lunar 620 the output from the regulator is
    12 volt and 12amp.
    Hope this helps

    Sandy
     
  18. pappajohn

    pappajohn Funster Life Member

    Joined:
    Aug 26, 2007
    Messages:
    31,258
    Location:
    YO11 2BD
    Ratings:
    +23,600
    still better than 8.5amp though and you can run other 230v appliances at the same time.

    my onboard was rated at 12amp as well 'til i bought a 25amp three stage charger and fitted that in its place:thumb:
     
  19. Gonewiththewind

    Gonewiththewind

    Joined:
    Sep 13, 2007
    Messages:
    854
    Location:
    Lancashire
    Ratings:
    +35
    Your Adding words mate, he said "better to ":ROFLMAO:

    Don
     
Loading...

Share This Page